This info manual describes how to use and administer CVS version 1.12.13-MirOS-0AB9.1 and up.
This chapter is for people who have never used CVS, and perhaps have never used version control software before.
If you are already familiar with CVS and are just trying to learn a particular feature or remember a certain command, you can probably skip everything here.
CVS is a version control system. Using it, you can record the history of your source files.
For example, bugs sometimes creep in when software is modified, and you might not detect the bug until a long time after you make the modification. With CVS, you can easily retrieve old versions to see exactly which change caused the bug. This can sometimes be a big help.
You could of course save every version of every file you have ever created. This would however waste an enormous amount of disk space. CVS stores all the versions of a file in a single file in a clever way that only stores the differences between versions.
CVS also helps you if you are part of a group of people working on the same project. It is all too easy to overwrite each others’ changes unless you are extremely careful. Some editors, like GNU Emacs, try to make sure that two people never modify the same file at the same time. Unfortunately, if someone is using another editor, that safeguard will not work. CVS solves this problem by insulating the different developers from each other. Every developer works in his own directory, and CVS merges the work when each developer is done.
CVS started out as a bunch of shell scripts written by
Dick Grune, posted to the newsgroup
comp.sources.unix in the volume 6
release of July, 1986. While no actual code from
these shell scripts is present in the current version
of CVS much of the CVS conflict resolution algorithms
come from them.
In April, 1989, Brian Berliner designed and coded CVS. Jeff Polk later helped Brian with the design of the CVS module and vendor branch support.
You can get CVS in a variety of ways, including free download from the Internet. For more information on downloading CVS and other CVS topics, see:
There is a mailing list, known as info-cvs@nongnu.org,
devoted to CVS. To subscribe or
unsubscribe
write to
info-cvs-request@nongnu.org.
If you prefer a Usenet group, there is a one-way mirror (posts to the email
list are usually sent to the news group, but not visa versa) of
info-cvs@nongnu.org at news:gnu.cvs.help. The right
Usenet group for posts is news:comp.software.config-mgmt which is for
CVS discussions (along with other configuration
management systems). In the future, it might be
possible to create a
comp.software.config-mgmt.cvs, but probably only
if there is sufficient CVS traffic on
news:comp.software.config-mgmt.
You can also subscribe to the bug-cvs@nongnu.org mailing list, described in more detail in Dealing with bugs in CVS or this manual. To subscribe send mail to bug-cvs-request@nongnu.org. There is a two-way Usenet mirror (posts to the Usenet group are usually sent to the email list and visa versa) of bug-cvs@nongnu.org named news:gnu.cvs.bug.
CVS can do a lot of things for you, but it does not try to be everything for everyone.
Though the structure of your repository and modules file interact with your build system (e.g. Makefiles), they are essentially independent.
CVS does not dictate how you build anything. It merely stores files for retrieval in a tree structure you devise.
CVS does not dictate how to use disk space in the checked out working directories. If you write your Makefiles or scripts in every directory so they have to know the relative positions of everything else, you wind up requiring the entire repository to be checked out.
If you modularise your work, and construct a build
system that will share files (via links, mounts,
VPATH in Makefiles, etc.), you can
arrange your disk usage however you like.
But you have to remember that any such system is a lot of work to construct and maintain. CVS does not address the issues involved.
Of course, you should place the tools created to support such a build system (scripts, Makefiles, etc) under CVS.
Figuring out what files need to be rebuilt when
something changes is, again, something to be handled
outside the scope of CVS. One traditional
approach is to use make for building, and use
some automated tool for generating the dependencies which
make uses.
See How your build system interacts with CVS, for more information on doing builds in conjunction with CVS.
Your managers and project leaders are expected to talk to you frequently enough to make certain you are aware of schedules, merge points, branch names and release dates. If they don’t, CVS can’t help.
CVS is an instrument for making sources dance to your tune. But you are the piper and the composer. No instrument plays itself or writes its own music.
When faced with conflicts within a single file, most developers manage to resolve them without too much effort. But a more general definition of “conflict” includes problems too difficult to solve without communication between developers.
CVS cannot determine when simultaneous changes
within a single file, or across a whole collection of
files, will logically conflict with one another. Its
concept of a conflict is purely textual, arising
when two changes to the same base file are near enough
to spook the merge (i.e. diff3) command.
CVS does not claim to help at all in figuring out non-textual or distributed conflicts in program logic.
For example: Say you change the arguments to function
X defined in file A. At the same time,
someone edits file B, adding new calls to
function X using the old arguments. You are
outside the realm of CVS’s competence.
Acquire the habit of reading specs and talking to your peers.
Change control refers to a number of things. First of all it can mean bug-tracking, that is being able to keep a database of reported bugs and the status of each one (is it fixed? in what release? has the bug submitter agreed that it is fixed?). For interfacing CVS to an external bug-tracking system, see the rcsinfo and verifymsg files (see Reference manual for Administrative files).
Another aspect of change control is keeping track of
the fact that changes to several files were in fact
changed together as one logical change. If you check
in several files in a single cvs commit
operation, CVS then forgets that those files were
checked in together, and the fact that they have the
same log message is the only thing tying them
together. Keeping a GNU style ChangeLog
can help somewhat.
Another aspect of change control, in some systems, is
the ability to keep track of the status of each
change. Some changes have been written by a developer,
others have been reviewed by a second developer, and so
on. Generally, the way to do this with CVS is to
generate a diff (using cvs diff or diff)
and email it to someone who can then apply it using the
patch utility. This is very flexible, but
depends on mechanisms outside CVS to make sure
nothing falls through the cracks.
It should be possible to enforce mandatory use of a
test suite using the commitinfo file. I haven’t
heard a lot about projects trying to do that or whether
there are subtle gotchas, however.
Some systems provide ways to ensure that changes or releases go through various steps, with various approvals as needed. Generally, one can accomplish this with CVS but it might be a little more work. In some cases you’ll want to use the commitinfo, loginfo, rcsinfo, or verifymsg files, to require that certain steps be performed before cvs will allow a checkin. Also consider whether features such as branches and tags can be used to perform tasks such as doing work in a development tree and then merging certain changes over to a stable tree only once they have been proven.
As a way of introducing CVS, we’ll go through a typical work-session using CVS. The first thing to understand is that CVS stores all files in a centralised repository (see The Repository); this section assumes that a repository is set up.
Suppose you are working on a simple compiler. The source consists of a handful of C files and a Makefile. The compiler is called ‘tc’ (Trivial Compiler), and the repository is set up so that there is a module called ‘tc’.
The first thing you must do is to get your own working copy of the
source for ‘tc’. For this, you use the checkout command:
$ cvs checkout tc
This will create a new directory called tc and populate it with the source files.
$ cd tc $ ls CVS Makefile backend.c driver.c frontend.c parser.c
The CVS directory is used internally by CVS. Normally, you should not modify or remove any of the files in it.
You start your favorite editor, hack away at backend.c, and a couple of hours later you have added an optimization pass to the compiler. A note to RCS and SCCS users: There is no need to lock the files that you want to edit. See Multiple developers, for an explanation.
When you have checked that the compiler is still compilable you decide to make a new version of backend.c. This will store your new backend.c in the repository and make it available to anyone else who is using that same repository.
$ cvs commit backend.c
CVS starts an editor, to allow you to enter a log message. You type in “Added an optimization pass.”, save the temporary file, and exit the editor.
The environment variable $CVSEDITOR determines
which editor is started. If $CVSEDITOR is not
set, then if the environment variable $EDITOR is
set, it will be used. If both $CVSEDITOR and
$EDITOR are not set then there is a default
which will vary with your operating system, for example
vi for unix or notepad for Windows
NT/95.
In addition, CVS checks the $VISUAL environment
variable. Opinions vary on whether this behavior is desirable and
whether future releases of CVS should check $VISUAL or
ignore it. You will be OK either way if you make sure that
$VISUAL is either unset or set to the same thing as
$EDITOR.
When CVS starts the editor, it includes a list of
files which are modified. For the CVS client,
this list is based on comparing the modification time
of the file against the modification time that the file
had when it was last gotten or updated. Therefore, if
a file’s modification time has changed but its contents
have not, it will show up as modified. The simplest
way to handle this is simply not to worry about it—if
you proceed with the commit CVS will detect that
the contents are not modified and treat it as an
unmodified file. The next update will clue
CVS in to the fact that the file is unmodified,
and it will reset its stored timestamp so that the file
will not show up in future editor sessions.
If you want to avoid starting an editor you can specify the log message on the command line using the ‘-m’ flag instead, like this:
$ cvs commit -m "Added an optimization pass" backend.c
Before you turn to other tasks you decide to remove your working copy of tc. One acceptable way to do that is of course
$ cd .. $ rm -r tc
but a better way is to use the release command (see release—Indicate that a directory is no longer in use):
$ cd .. $ cvs release -d tc M driver.c ? tc You have [1] altered files in this repository. Are you sure you want to release (and delete) directory `tc': n ** `release' aborted by user choice.
The release command checks that all your modifications have been
committed. If history logging is enabled it also makes a note in the
history file. See The history file.
When you use the ‘-d’ flag with release, it
also removes your working copy.
In the example above, the release command wrote a couple of lines
of output. ‘? tc’ means that the file tc is unknown to CVS.
That is nothing to worry about: tc is the executable compiler,
and it should not be stored in the repository. See Ignoring files via cvsignore,
for information about how to make that warning go away.
See release output, for a complete explanation of
all possible output from release.
‘M driver.c’ is more serious. It means that the file driver.c has been modified since it was checked out.
The release command always finishes by telling
you how many modified files you have in your working
copy of the sources, and then asks you for confirmation
before deleting any files or making any note in the
history file.
You decide to play it safe and answer n RET
when release asks for confirmation.
You do not remember modifying driver.c, so you want to see what has happened to that file.
$ cd tc $ cvs diff driver.c
This command runs diff to compare the version of driver.c
that you checked out with your working copy. When you see the output
you remember that you added a command line option that enabled the
optimization pass. You check it in, and release the module.
$ cvs commit -m "Added an optimization pass" driver.c Checking in driver.c; /usr/local/cvsroot/tc/driver.c,v <-- driver.c new revision: 1.2; previous revision: 1.1 done $ cd .. $ cvs release -d tc ? tc You have [0] altered files in this repository. Are you sure you want to release (and delete) directory `tc': y
The CVS repository stores a complete copy of all the files and directories which are under version control.
Normally, you never access any of the files in the repository directly. Instead, you use CVS commands to get your own copy of the files into a working directory, and then work on that copy. When you’ve finished a set of changes, you check (or commit) them back into the repository. The repository then contains the changes which you have made, as well as recording exactly what you changed, when you changed it, and other such information. Note that the repository is not a subdirectory of the working directory, or vice versa; they should be in separate locations.
CVS can access a repository by a variety of
means. It might be on the local computer, or it might
be on a computer across the room or across the world.
To distinguish various ways to access a repository, the
repository name can start with an access method.
For example, the access method :local: means to
access a repository directory, so the repository
:local:/usr/local/cvsroot means that the
repository is in /usr/local/cvsroot on the
computer running CVS. For information on other
access methods, see Remote repositories.
If the access method is omitted, then if the repository
starts with ‘/’, then :local: is
assumed. If it does not start with ‘/’ then either
:ext: or :server: is assumed. For
example, if you have a local repository in
/usr/local/cvsroot, you can use
/usr/local/cvsroot instead of
:local:/usr/local/cvsroot. But if (under
Windows NT, for example) your local repository is
c:\src\cvsroot, then you must specify the access
method, as in :local:c:/src/cvsroot.
The repository is split in two parts. $CVSROOT/CVSROOT contains administrative files for CVS. The other directories contain the actual user-defined modules.
There are several ways to tell CVS
where to find the repository. You can name the
repository on the command line explicitly, with the
-d (for "directory") option:
cvs -d /usr/local/cvsroot checkout yoyodyne/tc
Or you can set the $CVSROOT environment
variable to an absolute path to the root of the
repository, /usr/local/cvsroot in this example.
To set $CVSROOT, csh and tcsh
users should have this line in their .cshrc or
.tcshrc files:
setenv CVSROOT /usr/local/cvsroot
sh and bash users should instead have these lines in their
.profile or .bashrc:
CVSROOT=/usr/local/cvsroot export CVSROOT
A repository specified with -d will
override the $CVSROOT environment variable.
Once you’ve checked a working copy out from the
repository, it will remember where its repository is
(the information is recorded in the
CVS/Root file in the working copy).
The -d option and the CVS/Root file both
override the $CVSROOT environment variable. If
-d option differs from CVS/Root, the
former is used. Of course, for proper operation they
should be two ways of referring to the same repository.
For most purposes it isn’t important how CVS stores information in the repository. In fact, the format has changed in the past, and is likely to change in the future. Since in almost all cases one accesses the repository via CVS commands, such changes need not be disruptive.
However, in some cases it may be necessary to understand how CVS stores data in the repository, for example you might need to track down CVS locks (see Several developers simultaneously attempting to run CVS) or you might need to deal with the file permissions appropriate for the repository.
The overall structure of the repository is a directory tree corresponding to the directories in the working directory. For example, supposing the repository is in
/usr/local/cvsroot
here is a possible directory tree (showing only the directories):
/usr| +--local| | | +--cvsroot| | | | | +--CVSROOT| (administrative files) | +--gnu| | | +--diff| | (source code to GNU diff) | | | +--rcs| | (source code to RCS) | | | +--cvs| (source code to CVS) | +--yoyodyne| +--tc| | | +--man| | | +--testing| +--(other Yoyodyne software)
With the directories are history files for each file under version control. The name of the history file is the name of the corresponding file with ‘,v’ appended to the end. Here is what the repository for the yoyodyne/tc directory might look like:
$CVSROOT| +--yoyodyne| | | +--tc| | | +--Makefile,v+--backend.c,v+--driver.c,v+--frontend.c,v+--parser.c,v+--man| | | +--tc.1,v| +--testing| +--testpgm.t,v+--test2.t,v
The history files contain, among other things, enough
information to recreate any revision of the file, a log
of all commit messages and the user-name of the person
who committed the revision. The history files are
known as RCS files, because the first program to
store files in that format was a version control system
known as RCS. For a full
description of the file format, see the man page
rcsfile(5), distributed with RCS, or the
file doc/RCSFILES in the CVS source
distribution. This
file format has become very common—many systems other
than CVS or RCS can at least import history
files in this format.
The RCS files used in CVS differ in a few ways from the standard format. The biggest difference is magic branches; for more information see Magic branch numbers. Also in CVS the valid tag names are a subset of what RCS accepts; for CVS’s rules see Tags–Symbolic revisions.
All ‘,v’ files are created read-only, and you should not change the permission of those files. The directories inside the repository should be writable by the persons that have permission to modify the files in each directory. This normally means that you must create a UNIX group (see group(5)) consisting of the persons that are to edit the files in a project, and set up the repository so that it is that group that owns the directory. (On some systems, you also need to set the set-group-ID-on-execution bit on the repository directories (see chmod(1)) so that newly-created files and directories get the group-ID of the parent directory rather than that of the current process.)
This means that you can only control access to files on a per-directory basis.
Note that users must also have write access to check out files, because CVS needs to create lock files (see Several developers simultaneously attempting to run CVS). You can use LockDir in CVSROOT/config to put the lock files somewhere other than in the repository if you want to allow read-only access to some directories (see The CVSROOT/config configuration file).
Also note that users must have write access to the CVSROOT/val-tags file. CVS uses it to keep track of what tags are valid tag names (it is sometimes updated when tags are used, as well as when they are created).
Each RCS file will be owned by the user who last checked it in. This has little significance; what really matters is who owns the directories.
CVS tries to set up reasonable file permissions
for new directories that are added inside the tree, but
you must fix the permissions manually when a new
directory should have different permissions than its
parent directory. If you set the CVSUMASK
environment variable that will control the file
permissions which CVS uses in creating directories
and/or files in the repository. CVSUMASK does
not affect the file permissions in the working
directory; such files have the permissions which are
typical for newly created files, except that sometimes
CVS creates them read-only (see the sections on
watches, Telling CVS to watch certain files; -r, Global options; or CVSREAD, All environment variables which affect CVS).
Note that using the client/server CVS
(see Remote repositories), there is no good way to
set CVSUMASK; the setting on the client machine
has no effect. If you are connecting with rsh, you
can set CVSUMASK in .bashrc or .cshrc, as
described in the documentation for your operating
system. This behavior might change in future versions
of CVS; do not rely on the setting of
CVSUMASK on the client having no effect.
Using pserver, you will generally need stricter permissions on the CVSROOT directory and directories above it in the tree; see Security considerations with password authentication.
Some operating systems have features which allow a particular program to run with the ability to perform operations which the caller of the program could not. For example, the set user ID (setuid) or set group ID (setgid) features of unix or the installed image feature of VMS. CVS was not written to use such features and therefore attempting to install CVS in this fashion will provide protection against only accidental lapses; anyone who is trying to circumvent the measure will be able to do so, and depending on how you have set it up may gain access to more than just CVS. You may wish to instead consider pserver. It shares some of the same attributes, in terms of possibly providing a false sense of security or opening security holes wider than the ones you are trying to fix, so read the documentation on pserver security carefully if you are considering this option (Security considerations with password authentication).
Some file permission issues are specific to Windows operating systems (Windows 95, Windows NT, and presumably future operating systems in this family. Some of the following might apply to OS/2 but I’m not sure).
If you are using local CVS and the repository is on a networked filesystem which is served by the Samba SMB server, some people have reported problems with permissions. Enabling WRITE=YES in the samba configuration is said to fix/workaround it. Disclaimer: I haven’t investigated enough to know the implications of enabling that option, nor do I know whether there is something which CVS could be doing differently in order to avoid the problem. If you find something out, please let us know as described in Dealing with bugs in CVS or this manual.
You will notice that sometimes CVS stores an
RCS file in the Attic. For example, if the
CVSROOT is /usr/local/cvsroot and we are
talking about the file backend.c in the
directory yoyodyne/tc, then the file normally
would be in
/usr/local/cvsroot/yoyodyne/tc/backend.c,v
but if it goes in the attic, it would be in
/usr/local/cvsroot/yoyodyne/tc/Attic/backend.c,v
instead. It should not matter from a user point of
view whether a file is in the attic; CVS keeps
track of this and looks in the attic when it needs to.
But in case you want to know, the rule is that the RCS
file is stored in the attic if and only if the head
revision on the trunk has state dead. A
dead state means that file has been removed, or
never added, for that revision. For example, if you
add a file on a branch, it will have a trunk revision
in dead state, and a branch revision in a
non-dead state.
The CVS directory in each repository directory contains information such as file attributes (in a file called CVS/fileattr. In the future additional files may be added to this directory, so implementations should silently ignore additional files.
This behavior is implemented only by CVS 1.7 and later; for details see Using watches with old versions of CVS.
The format of the fileattr file is a series of entries of the following form (where ‘{’ and ‘}’ means the text between the braces can be repeated zero or more times):
ent-type filename <tab> attrname = attrval {; attrname = attrval} <linefeed>
ent-type is ‘F’ for a file, in which case the entry specifies the attributes for that file.
ent-type is ‘D’, and filename empty, to specify default attributes to be used for newly added files.
Other ent-type are reserved for future expansion. CVS 1.9 and older will delete them any time it writes file attributes. CVS 1.10 and later will preserve them.
Note that the order of the lines is not significant; a program writing the fileattr file may rearrange them at its convenience.
There is currently no way of quoting tabs or line feeds in the filename, ‘=’ in attrname, ‘;’ in attrval, etc. Note: some implementations also don’t handle a NUL character in any of the fields, but implementations are encouraged to allow it.
By convention, attrname starting with ‘_’ is for an attribute given special meaning by CVS; other attrnames are for user-defined attributes (or will be, once implementations start supporting user-defined attributes).
Built-in attributes:
_watchedPresent means the file is watched and should be checked out read-only.
_watchersUsers with watches for this file. Value is watcher > type { , watcher > type } where watcher is a username, and type is zero or more of edit,unedit,commit separated by ‘+’ (that is, nothing if none; there is no "none" or "all" keyword).
_editorsUsers editing this file. Value is
editor > val { , editor > val }
where editor is a username, and val is
time+hostname+pathname, where
time is when the cvs edit command (or
equivalent) happened,
and hostname and pathname are for the working directory.
Example:
Ffile1 _watched=;_watchers=joe>edit,mary>commit Ffile2 _watched=;_editors=sue>8 Jan 1975+workstn1+/home/sue/cvs D _watched=
means that the file file1 should be checked out
read-only. Furthermore, joe is watching for edits and
mary is watching for commits. The file file2
should be checked out read-only; sue started editing it
on 8 Jan 1975 in the directory /home/sue/cvs on
the machine workstn1. Future files which are
added should be checked out read-only. To represent
this example here, we have shown a space after
‘D’, ‘Ffile1’, and ‘Ffile2’, but in fact
there must be a single tab character there and no spaces.
For an introduction to CVS locks focusing on user-visible behavior, see Several developers simultaneously attempting to run CVS. The following section is aimed at people who are writing tools which want to access a CVS repository without interfering with other tools accessing the same repository. If you find yourself confused by concepts described here, like read lock, write lock, and deadlock, you might consult the literature on operating systems or databases.
Any file in the repository with a name starting with #cvs.rfl. is a read lock. Any file in the repository with a name starting with #cvs.pfl is a promotable read lock. Any file in the repository with a name starting with #cvs.wfl is a write lock. Old versions of CVS (before CVS 1.5) also created files with names starting with #cvs.tfl, but they are not discussed here. The directory #cvs.lock serves as a master lock. That is, one must obtain this lock first before creating any of the other locks.
To obtain a read lock, first create the #cvs.lock directory. This operation must be atomic (which should be true for creating a directory under most operating systems). If it fails because the directory already existed, wait for a while and try again. After obtaining the #cvs.lock lock, create a file whose name is #cvs.rfl. followed by information of your choice (for example, hostname and process identification number). Then remove the #cvs.lock directory to release the master lock. Then proceed with reading the repository. When you are done, remove the #cvs.rfl file to release the read lock.
Promotable read locks are a concept you may not find in other literature on concurrency. They are used to allow a two (or more) pass process to only lock a file for read on the first (read) pass(es), then upgrade its read locks to write locks if necessary for a final pass, still assured that the files have not changed since they were first read. CVS uses promotable read locks, for example, to prevent commit and tag verification passes from interfering with other reading processes. It can then lock only a single directory at a time for write during the write pass.
To obtain a promotable read lock, first create the #cvs.lock directory, as with a non-promotable read lock. Then check that there are no files that start with #cvs.pfl. If there are, remove the master #cvs.lock directory, wait awhile (CVS waits 30 seconds between lock attempts), and try again. If there are no other promotable locks, go ahead and create a file whose name is #cvs.pfl followed by information of your choice (for example, CVS uses its hostname and the process identification number of the CVS server process creating the lock). If versions of CVS older than version 1.12.4 access your repository directly (not via a CVS server of version 1.12.4 or later), then you should also create a read lock since older versions of CVS will ignore the promotable lock when attempting to create their own write lock. Then remove the master #cvs.lock directory in order to allow other processes to obtain read locks.
To obtain a write lock, first create the #cvs.lock directory, as with read locks. Then check that there are no files whose names start with #cvs.rfl. and no files whose names start with #cvs.pfl that are not owned by the process attempting to get the write lock. If either exist, remove #cvs.lock, wait for a while, and try again. If there are no readers or promotable locks from other processes, then create a file whose name is #cvs.wfl followed by information of your choice (again, CVS uses the hostname and server process identification number). Remove your #cvs.pfl file if present. Hang on to the #cvs.lock lock. Proceed with writing the repository. When you are done, first remove the #cvs.wfl file and then the #cvs.lock directory. Note that unlike the #cvs.rfl file, the #cvs.wfl file is just informational; it has no effect on the locking operation beyond what is provided by holding on to the #cvs.lock lock itself.
Note that each lock (write lock or read lock) only locks a single directory in the repository, including Attic and CVS but not including subdirectories which represent other directories under version control. To lock an entire tree, you need to lock each directory (note that if you fail to obtain any lock you need, you must release the whole tree before waiting and trying again, to avoid deadlocks).
Note also that CVS expects write locks to control access to individual foo,v files. RCS has a scheme where the ,foo, file serves as a lock, but CVS does not implement it and so taking out a CVS write lock is recommended. See the comments at rcs_internal_lockfile in the CVS source code for further discussion/rationale.
The $CVSROOT/CVSROOT directory contains the various administrative files. In some ways this directory is just like any other directory in the repository; it contains RCS files whose names end in ‘,v’, and many of the CVS commands operate on it the same way. However, there are a few differences.
For each administrative file, in addition to the RCS file, there is also a checked out copy of the file. For example, there is an RCS file loginfo,v and a file loginfo which contains the latest revision contained in loginfo,v. When you check in an administrative file, CVS should print
cvs commit: Rebuilding administrative file database
and update the checked out copy in $CVSROOT/CVSROOT. If it does not, there is something wrong (see Dealing with bugs in CVS or this manual). To add your own files to the files to be updated in this fashion, you can add them to the checkoutlist administrative file (see The checkoutlist file).
By default, the modules file behaves as
described above. If the modules file is very large,
storing it as a flat text file may make looking up
modules slow (I’m not sure whether this is as much of a
concern now as when CVS first evolved this
feature; I haven’t seen benchmarks). Therefore, by
making appropriate edits to the CVS source code
one can store the modules file in a database which
implements the ndbm interface, such as Berkeley
db or GDBM. If this option is in use, then the modules
database will be stored in the files modules.db,
modules.pag, and/or modules.dir.
For information on the meaning of the various administrative files, see Reference manual for Administrative files.
While we are discussing CVS internals which may
become visible from time to time, we might as well talk
about what CVS puts in the CVS directories
in the working directories. As with the repository,
CVS handles this information and one can usually
access it via CVS commands. But in some cases it
may be useful to look at it, and other programs, such
as the jCVS graphical user interface or the
VC package for emacs, may need to look at it.
Such programs should follow the recommendations in this
section if they hope to be able to work with other
programs which use those files, including future
versions of the programs just mentioned and the
command-line CVS client.
The CVS directory contains several files. Programs which are reading this directory should silently ignore files which are in the directory but which are not documented here, to allow for future expansion.
The files are stored according to the text file convention for the system in question. This means that working directories are not portable between systems with differing conventions for storing text files. This is intentional, on the theory that the files being managed by CVS probably will not be portable between such systems either.
This file contains the current CVS root, as described in Telling CVS where your repository is.
This file contains the directory within the repository which the current directory corresponds with. It can be either an absolute pathname or a relative pathname; CVS has had the ability to read either format since at least version 1.3 or so. The relative pathname is relative to the root, and is the more sensible approach, but the absolute pathname is quite common and implementations should accept either. For example, after the command
cvs -d :local:/usr/local/cvsroot checkout yoyodyne/tc
Root will contain
:local:/usr/local/cvsroot
and Repository will contain either
/usr/local/cvsroot/yoyodyne/tc
or
yoyodyne/tc
If the particular working directory does not correspond to a directory in the repository, then Repository should contain CVSROOT/Emptydir.
This file lists the files and directories in the working directory. The first character of each line indicates what sort of line it is. If the character is unrecognised, programs reading the file should silently skip that line, to allow for future expansion.
If the first character is ‘/’, then the format is:
/name/revision/timestamp[+conflict]/options/tagdate
where ‘[’ and ‘]’ are not part of the entry, but instead indicate that the ‘+’ and conflict marker are optional. name is the name of the file within the directory. revision is the revision that the file in the working derives from, or ‘0’ for an added file, or ‘-’ followed by a revision for a removed file. timestamp is the timestamp of the file at the time that CVS created it; if the timestamp differs with the actual modification time of the file it means the file has been modified. It is stored in the format used by the ISO C asctime() function (for example, ‘Sun Apr 7 01:29:26 1996’). One may write a string which is not in that format, for example, ‘Result of merge’, to indicate that the file should always be considered to be modified. This is not a special case; to see whether a file is modified a program should take the timestamp of the file and simply do a string compare with timestamp. If there was a conflict, conflict can be set to the modification time of the file after the file has been written with conflict markers (see Conflicts example). Thus if conflict is subsequently the same as the actual modification time of the file it means that the user has obviously not resolved the conflict. options contains sticky options (for example ‘-kb’ for a binary file). tagdate contains ‘T’ followed by a tag name, or ‘D’ for a date, followed by a sticky tag or date. Note that if timestamp contains a pair of timestamps separated by a space, rather than a single timestamp, you are dealing with a version of CVS earlier than CVS 1.5 (not documented here).
The timezone on the timestamp in CVS/Entries (local or universal) should be the same as the operating system stores for the timestamp of the file itself. For example, on Unix the file’s timestamp is in universal time (UT), so the timestamp in CVS/Entries should be too. On VMS, the file’s timestamp is in local time, so CVS on VMS should use local time. This rule is so that files do not appear to be modified merely because the timezone changed (for example, to or from summer time).
If the first character of a line in Entries is ‘D’, then it indicates a subdirectory. ‘D’ on a line all by itself indicates that the program which wrote the Entries file does record subdirectories (therefore, if there is such a line and no other lines beginning with ‘D’, one knows there are no subdirectories). Otherwise, the line looks like:
D/name/filler1/filler2/filler3/filler4
where name is the name of the subdirectory, and
all the filler fields should be silently ignored,
for future expansion. Programs which modify
Entries files should preserve these fields.
The lines in the Entries file can be in any order.
This file does not record any information beyond that in Entries, but it does provide a way to update the information without having to rewrite the entire Entries file, including the ability to preserve the information even if the program writing Entries and Entries.Log abruptly aborts. Programs which are reading the Entries file should also check for Entries.Log. If the latter exists, they should read Entries and then apply the changes mentioned in Entries.Log. After applying the changes, the recommended practice is to rewrite Entries and then delete Entries.Log. The format of a line in Entries.Log is a single character command followed by a space followed by a line in the format specified for a line in Entries. The single character command is ‘A’ to indicate that the entry is being added, ‘R’ to indicate that the entry is being removed, or any other character to indicate that the entire line in Entries.Log should be silently ignored (for future expansion). If the second character of the line in Entries.Log is not a space, then it was written by an older version of CVS (not documented here).
Programs which are writing rather than reading can safely ignore Entries.Log if they so choose.
This is a temporary file. Recommended usage is to write a new entries file to Entries.Backup, and then to rename it (atomically, where possible) to Entries.
The only relevant thing about this file is whether it
exists or not. If it exists, then it means that only
part of a directory was gotten and CVS will
not create additional files in that directory. To
clear it, use the update command with the
‘-d’ option, which will get the additional files
and remove Entries.Static.
This file contains per-directory sticky tags or dates. The first character is ‘T’ for a branch tag, ‘N’ for a non-branch tag, or ‘D’ for a date, or another character to mean the file should be silently ignored, for future expansion. This character is followed by the tag or date. Note that per-directory sticky tags or dates are used for things like applying to files which are newly added; they might not be the same as the sticky tags or dates on individual files. For general information on sticky tags and dates, see Sticky tags.
This file stores notifications (for example, for
edit or unedit) which have not yet been
sent to the server. Its format is not yet documented
here.
This file is to Notify as Entries.Backup is to Entries. That is, to write Notify, first write the new contents to Notify.tmp and then (atomically where possible), rename it to Notify.
If watches are in use, then an edit command
stores the original copy of the file in the Base
directory. This allows the unedit command to
operate even if it is unable to communicate with the
server.
The file lists the revision for each of the files in the Base directory. The format is:
Bname/rev/expansion
where expansion should be ignored, to allow for future expansion.
This file is to Baserev as Entries.Backup is to Entries. That is, to write Baserev, first write the new contents to Baserev.tmp and then (atomically where possible), rename it to Baserev.
This file contains the template specified by the rcsinfo file (see Rcsinfo). It is only used by the client; the non-client/server CVS consults rcsinfo directly.
The directory $CVSROOT/CVSROOT contains some administrative files. See Reference manual for Administrative files, for a complete description. You can use CVS without any of these files, but some commands work better when at least the modules file is properly set up.
The most important of these files is the modules file. It defines all modules in the repository. This is a sample modules file.
CVSROOT CVSROOT modules CVSROOT modules cvs gnu/cvs rcs gnu/rcs diff gnu/diff tc yoyodyne/tc
The modules file is line oriented. In its
simplest form each line contains the name of the
module, whitespace, and the directory where the module
resides. The directory is a path relative to
$CVSROOT. The last four lines in the example
above are examples of such lines.
The line that defines the module called ‘modules’ uses features that are not explained here. See The modules file, for a full explanation of all the available features.
You edit the administrative files in the same way that you would edit any other module. Use ‘cvs checkout CVSROOT’ to get a working copy, edit it, and commit your changes in the normal way.
It is possible to commit an erroneous administrative file. You can often fix the error and check in a new revision, but sometimes a particularly bad error in the administrative file makes it impossible to commit new revisions.
In some situations it is a good idea to have more than
one repository, for instance if you have two
development groups that work on separate projects
without sharing any code. All you have to do to have
several repositories is to specify the appropriate
repository, using the CVSROOT environment
variable, the ‘-d’ option to CVS, or (once
you have checked out a working directory) by simply
allowing CVS to use the repository that was used
to check out the working directory
(see Telling CVS where your repository is).
The big advantage of having multiple repositories is that they can reside on different servers. With CVS version 1.10, a single command cannot recurse into directories from different repositories. With development versions of CVS, you can check out code from multiple servers into your working directory. CVS will recurse and handle all the details of making connections to as many server machines as necessary to perform the requested command. Here is an example of how to set up a working directory:
cvs -d server1:/cvs co dir1 cd dir1 cvs -d server2:/root co sdir cvs update
The cvs co commands set up the working
directory, and then the cvs update command will
contact server2, to update the dir1/sdir subdirectory,
and server1, to update everything else.
This section describes how to set up a CVS repository for any sort of access method. After completing the setup described in this section, you should be able to access your CVS repository immediately via the local access method and several remote access methods. For more information on setting up remote access to the repository you create in this section, please read the section on See Remote repositories.
To set up a CVS repository, first choose the machine and disk on which you want to store the revision history of the source files. CPU and memory requirements are modest, so most machines should be adequate. For details see Server requirements.
To estimate disk space requirements, if you are importing RCS files from another system, the size of those files is the approximate initial size of your repository, or if you are starting without any version history, a rule of thumb is to allow for the server approximately three times the size of the code to be under CVS for the repository (you will eventually outgrow this, but not for a while). On the machines on which the developers will be working, you’ll want disk space for approximately one working directory for each developer (either the entire tree or a portion of it, depending on what each developer uses).
The repository should be accessible (directly or via a networked filesystem) from all machines which want to use CVS in server or local mode; the client machines need not have any access to it other than via the CVS protocol. It is not normally possible to use CVS to read from a repository which one only has read access to; CVS needs to be able to create lock files (see Several developers simultaneously attempting to run CVS).
If the environment variable $CVSREADONLYFS is defined,
however, CVS will allow read-only access without creating any
history entries or reader lock files. This allows doing most
usual repository operations except checkin in a fast way,
although if any other user is accessing the same data at the
same time, it may lead to corrupt data. This mode is best used
for publicly accessible anonymous CVS mirrors, not the main
working repository.
To create a repository, run the cvs init
command. It will set up an empty repository in the
CVS root specified in the usual way
(see The Repository). For example,
cvs -d /usr/local/cvsroot init
cvs init is careful to never overwrite any
existing files in the repository, so no harm is done if
you run cvs init on an already set-up
repository.
The repository is created honouring the $CVSUMASK
setting (see CVSUMASK), even the history and
val-tags files are not created world-writable any
more as in previous CVS versions. History logging is,
accordingly, configured to log write operations only; if
you don’t want that, edit or remove the ‘LogHistory’
entry in the config file (see The CVSROOT/config configuration file) and make
sure that all users who need to write that file can do so,
for example by using a $CVSUMASK of 002 (which is
also the default) and putting everyone into the same Unix
group (consider the security implications if you really
want to enable world-writable logging).
There is nothing particularly magical about the files in the repository; for the most part it is possible to back them up just like any other files. However, there are a few issues to consider.
The first is that to be paranoid, one should either not use CVS during the backup, or have the backup program lock CVS while doing the backup. To not use CVS, you might forbid logins to machines which can access the repository, turn off your CVS server, or similar mechanisms. The details would depend on your operating system and how you have CVS set up. To lock CVS, you would create #cvs.rfl locks in each repository directory. See Several developers simultaneously attempting to run CVS, for more on CVS locks. Having said all this, if you just back up without any of these precautions, the results are unlikely to be particularly dire. Restoring from backup, the repository might be in an inconsistent state, but this would not be particularly hard to fix manually.
When you restore a repository from backup, assuming that changes in the repository were made after the time of the backup, working directories which were not affected by the failure may refer to revisions which no longer exist in the repository. Trying to run CVS in such directories will typically produce an error message. One way to get those changes back into the repository is as follows:
cvs update and cvs diff to figure out
what has changed, and then when you are ready, commit
the changes into the repository.
Just as backing up the files in the repository is pretty much like backing up any other files, if you need to move a repository from one place to another it is also pretty much like just moving any other collection of files.
The main thing to consider is that working directories point to the repository. The simplest way to deal with a moved repository is to just get a fresh working directory after the move. Of course, you’ll want to make sure that the old working directory had been checked in before the move, or you figured out some other way to make sure that you don’t lose any changes. If you really do want to reuse the existing working directory, it should be possible with manual surgery on the CVS/Repository files. You can see How data is stored in the working directory, for information on the CVS/Repository and CVS/Root files, but unless you are sure you want to bother, it probably isn’t worth it.
Your working copy of the sources can be on a different machine than the repository. Using CVS in this manner is known as client/server operation. You run CVS on a machine which can mount your working directory, known as the client, and tell it to communicate to a machine which can mount the repository, known as the server. Generally, using a remote repository is just like using a local one, except that the format of the repository name is:
[:method:][[user][:password]@]hostname[:[port]]/path/to/repository
Specifying a password in the repository name is not recommended during
checkout, since this will cause CVS to store a cleartext copy of the
password in each created directory. cvs login first instead
(see Using the client with password authentication).
The details of exactly what needs to be set up depend on how you are connecting to the server.
For the protocol specification, see the CVS client/server protocol in The CVS client/server protocol.
The quick answer to what sort of machine is suitable as a server is that requirements are modest—a server with 32M of memory or even less can handle a fairly large source tree with a fair amount of activity.
The real answer, of course, is more complicated. Estimating the known areas of large memory consumption should be sufficient to estimate memory requirements. There are two such areas documented here; other memory consumption should be small by comparison (if you find that is not the case, let us know, as described in Dealing with bugs in CVS or this manual, so we can update this documentation).
The first area of big memory consumption is large checkouts, when using the CVS server. The server consists of two processes for each client that it is serving. Memory consumption on the child process should remain fairly small. Memory consumption on the parent process, particularly if the network connection to the client is slow, can be expected to grow to slightly more than the size of the sources in a single directory, or two megabytes, whichever is larger.
Multiplying the size of each CVS server by the number of servers which you expect to have active at one time should give an idea of memory requirements for the server. For the most part, the memory consumed by the parent process probably can be swap space rather than physical memory.
The second area of large memory consumption is
diff, when checking in large files. This is
required even for binary files. The rule of thumb is
to allow about ten times the size of the largest file
you will want to check in, although five times may be
adequate. For example, if you want to check in a file
which is 10 megabytes, you should have 100 megabytes of
memory on the machine doing the checkin (the server
machine for client/server, or the machine running
CVS for non-client/server). This can be swap
space rather than physical memory. Because the memory
is only required briefly, there is no particular need
to allow memory for more than one such checkin at a
time.
Resource consumption for the client is even more modest—any machine with enough capacity to run the operating system in question should have little trouble.
For information on disk space requirements, see Creating a repository.
In its simplest form, the method portion of the repository string (see Remote repositories) may be one of ‘ext’, ‘fork’, ‘gserver’, ‘kserver’, ‘local’, ‘pserver’, and, on some platforms, ‘server’.
If method is not specified, and the repository
name starts with a ‘/’, then the default is local.
If method is not specified, and the repository
name does not start with a ‘/’, then the default is ext
or server, depending on your platform; both the ‘ext’
and ‘server’ methods are described in Connecting with rsh.
The ext, fork, gserver, and pserver connection
methods all accept optional method options, specified as part of the
method string, like so:
:method[;option=arg...]:other_connection_data
CVS is not sensitive to the case of method or option, though it may sometimes be sensitive to the case of arg. The possible method options are as follows:
proxy=hostname ¶proxyport=portThese two method options can be used to connect via an HTTP tunnel style web proxy. hostname should be the name of the HTTP proxy server to connect through and port is the port number on the HTTP proxy server to connect via. port defaults to 8080.
NOTE: An HTTP proxy server is not the same as a CVS write proxy server - please see Distributing load across several CVS servers for more on CVS write proxies.
For example, to connect pserver via a web proxy listening on port 8000 of www.myproxy.net, you would use a method of:
:pserver;proxy=www.myproxy.net;proxyport=8000:connstr
NOTE: In the above example, the pserver connection string connstr
is still required to connect and authenticate to the CVS server, as noted in
the upcoming sections on password authentication, gserver, and
kserver. The example above only demonstrates a modification to the
method portion of the repository name.
These options first appeared in CVS version 1.12.7 and are valid as
modifcations to the gserver and pserver connection methods.
CVS_RSH=path ¶This method option can be used with the ext method to specify the path
the CVS client will use to find the remote shell used to contact the
CVS server and takes precedence over any path specified in the
$CVS_RSH environment variable (see Connecting with rsh). For
example, to connect to a CVS server via the local
/path/to/ssh/command command, you could choose to specify the following
path via the CVS_RSH method option:
:ext;CVS_RSH=/path/to/ssh/command:ext_connection_string
This method option first appeared in CVS version 1.12.11 and is valid only
as a modifcation to the ext connection method.
CVS_SERVER=path ¶This method option can be used with the ext and fork methods to
specify the path CVS will use to find the CVS executable on the
CVS server and takes precedence over any path specified in the
$CVS_SERVER environment variable (see Connecting with rsh). For
example, to select the remote /path/to/cvs/command executable as your
CVS server application on the CVS server machine, you could choose to
specify the following path via the CVS_SERVER method option:
:ext;CVS_SERVER=/path/to/cvs/command:ext_connection_string
or, to select an executable named ‘cvs-1.12.11’, assuming it is in your
$PATH on the CVS server:
:ext;CVS_SERVER=cvs-1.12.11:ext_connection_string
This method option first appeared in CVS version 1.12.11 and is valid
as a modifcation to both the ext and fork connection methods.
Redirect=boolean-state ¶The Redirect method option determines whether the CVS client will
allow a CVS server to redirect it to a different CVS server, usually
for write requests, as in a write proxy setup.
A boolean-state of any value acceptable for boolean CVSROOT/config
file options is acceptable here (see The CVSROOT/config configuration file). For example, ‘on’,
‘off’, ‘true’, and ‘false’ are all valid values for
boolean-state. boolean-state for the Redirect method option
defaults to ‘on’.
This option will have no effect when talking to any non-secondary CVS server. For more on write proxies and secondary servers, please see Distributing load across several CVS servers.
This method option first appeared in CVS version 1.12.11 and is valid only
as a modifcation to the ext connection method.
As a further example, to combine both the CVS_RSH and CVS_SERVER
options, a method specification like the following would work:
:ext;CVS_RSH=/path/to/ssh/command;CVS_SERVER=/path/to/cvs/command:
This means that you would not need to have
the CVS_SERVER or CVS_RSH environment
variables set correctly. See Connecting with rsh, for more details on
these environment variables.
CVS uses the ‘rsh’ protocol to perform these operations, so the remote user host needs to have a .rhosts file which grants access to the local user. Note that the program that CVS uses for this purpose may be specified using the --with-rsh flag to configure.
For example, suppose you are the user ‘mozart’ on the local machine ‘toe.example.com’, and the server machine is ‘faun.example.org’. On faun, put the following line into the file .rhosts in ‘bach’’s home directory:
toe.example.com mozart
Then test that ‘rsh’ is working with
rsh -l bach faun.example.org 'echo $PATH'
Next you have to make sure that rsh will be able
to find the server. Make sure that the path which
rsh printed in the above example includes the
directory containing a program named cvs which
is the server. You need to set the path in
.bashrc, .cshrc, etc., not .login
or .profile. Alternately, you can set the
environment variable CVS_SERVER on the client
machine to the filename of the server you want to use,
for example /usr/local/bin/cvs-1.6.
For the ext and fork methods, you may
also specify CVS_SERVER as an option in the
CVSROOT so that you may use different servers for
differnt roots. See Remote repositories for more
details.
There is no need to edit inetd.conf or start a CVS server daemon.
There are two access methods that you use in CVSROOT
for rsh. :server: specifies an internal rsh
client, which is supported only by some CVS ports.
This is not supported on most Unix-style systems.
:ext: specifies an external rsh program. By
default this is rsh (unless otherwise specified
by the --with-rsh flag to configure) but you may set the
CVS_RSH environment variable to invoke another
program which can access the remote server (for
example, remsh on HP-UX 9 because rsh is
something different, or ssh to allow the use of secure
and/or compressed connections). It must be a program which can
transmit data to and from the server without modifying
it; for example the Windows NT rsh is not
suitable since it by default translates between CRLF
and LF. The OS/2 CVS port has a hack to pass ‘-b’
to rsh to get around this, but since this could
potentially cause problems for programs other than the
standard rsh, it may change in the future. If
you set CVS_RSH to SSH or some other rsh
replacement, the instructions in the rest of this
section concerning .rhosts and so on are likely
to be inapplicable; consult the documentation for your rsh
replacement.
In the Debian and MirBSD versions of CVS, you can
also specify :extssh: to force use of the Secure
Shell, or :ext=prog: or :ext=/path/to/prog:
to specify the remote shell to use without needing to
touch the CVS_RSH environment variable.
You may choose to specify the CVS_RSH option as a method option
in the CVSROOT string to allow you to use different connection tools
for different roots (see The connection method). For example, allowing
some roots to use CVS_RSH=remsh and some to use
CVS_RSH=ssh for the ext method. See also
the Remote repositories for more details.
Continuing our example, supposing you want to access the module foo in the repository /usr/local/cvsroot/, on machine faun.example.org, you are ready to go:
cvs -d :ext:bach@faun.example.org:/usr/local/cvsroot checkout foo
(The bach@ can be omitted if the username is the same on both the local and remote hosts.)
The CVS client can also connect to the server
using a password protocol. This is particularly useful
if using rsh is not feasible (for example,
the server is behind a firewall), and Kerberos also is
not available.
To use this method, it is necessary to make some adjustments on both the server and client sides.
First of all, you probably want to tighten the permissions on the $CVSROOT and $CVSROOT/CVSROOT directories. See Security considerations with password authentication, for more details.
On the server side, the file /etc/inetd.conf
needs to be edited so inetd knows to run the
command cvs pserver when it receives a
connection on the right port. By default, the port
number is 2401; it would be different if your client
were compiled with CVS_AUTH_PORT defined to
something else, though. This can also be specified in the CVSROOT variable
(see Remote repositories) or overridden with the CVS_CLIENT_PORT
environment variable (see All environment variables which affect CVS).
If your inetd allows raw port numbers in
/etc/inetd.conf, then the following (all on a
single line in inetd.conf) should be sufficient:
2401 stream tcp nowait root /usr/local/bin/cvs cvs -f --allow-root=/usr/cvsroot pserver
(You could also use the ‘-T’ option to specify a temporary directory.)
The ‘--allow-root’ option specifies the allowable
CVSROOT directory. Clients which attempt to use a
different CVSROOT directory will not be allowed to
connect. To allow a whole class of CVSROOT, specify
a POSIX extended regular expression to match allowed
directories with the ‘--allow-root-regexp’ option.
These options may be used in conjunction, and both options
may be repeated to allow access to multiple CVSROOT
directories and classes of directories.
(Unfortunately, many versions of inetd have very small
limits on the number of arguments and/or the total length
of the command. The usual solution to this problem is
to have inetd run a shell script which then invokes
CVS with the necessary arguments.)
If your inetd wants a symbolic service
name instead of a raw port number, then put this in
/etc/services:
cvspserver 2401/tcp
and put cvspserver instead of 2401 in inetd.conf.
If your system uses xinetd instead of inetd,
the procedure is slightly different.
Create a file called /etc/xinetd.d/cvspserver containing the following:
service cvspserver
{
port = 2401
socket_type = stream
protocol = tcp
wait = no
user = root
passenv = PATH
server = /usr/local/bin/cvs
server_args = -f --allow-root=/usr/cvsroot pserver
}
(If cvspserver is defined in /etc/services, you can omit
the port line.)
Once the above is taken care of, restart your
inetd, or do whatever is necessary to force it
to reread its initialization files.
If you are having trouble setting this up, see Trouble making a connection to a CVS server.
Because the client stores and transmits passwords in cleartext (almost—see Security considerations with password authentication, for details), a separate CVS password file is generally used, so people don’t compromise their regular passwords when they access the repository. This file is $CVSROOT/CVSROOT/passwd (see The administrative files). It uses a colon-separated format, similar to /etc/passwd on Unix systems, except that it has fewer fields: CVS username, optional password, and an optional system username for CVS to run as if authentication succeeds. Here is an example passwd file with five entries:
anonymous: bach:ULtgRLXo7NRxs spwang:1sOp854gDF3DY melissa:tGX1fS8sun6rY:pubcvs qproj:XR4EZcEs0szik:pubcvs
(The passwords are encrypted according to the standard
Unix crypt() function, so it is possible to
paste in passwords directly from regular Unix
/etc/passwd files.)
The first line in the example will grant access to any
CVS client attempting to authenticate as user
anonymous, no matter what password they use,
including an empty password. (This is typical for
sites granting anonymous read-only access; for
information on how to do the "read-only" part, see
Read-only repository access.)
The second and third lines will grant access to
bach and spwang if they supply their
respective plaintext passwords.
The fourth line will grant access to melissa, if
she supplies the correct password, but her CVS
operations will actually run on the server side under
the system user pubcvs. Thus, there need not be
any system user named melissa, but there
must be one named pubcvs.
The fifth line shows that system user identities can be
shared: any client who successfully authenticates as
qproj will actually run as pubcvs, just
as melissa does. That way you could create a
single, shared system user for each project in your
repository, and give each developer their own line in
the $CVSROOT/CVSROOT/passwd file. The CVS
username on each line would be different, but the
system username would be the same. The reason to have
different CVS usernames is that CVS will log their
actions under those names: when melissa commits
a change to a project, the checkin is recorded in the
project’s history under the name melissa, not
pubcvs. And the reason to have them share a
system username is so that you can arrange permissions
in the relevant area of the repository such that only
that account has write-permission there.
If the system-user field is present, all password-authenticated CVS commands run as that user; if no system user is specified, CVS simply takes the CVS username as the system username and runs commands as that user. In either case, if there is no such user on the system, then the CVS operation will fail (regardless of whether the client supplied a valid password).
The password and system-user fields can both be omitted (and if the system-user field is omitted, then also omit the colon that would have separated it from the encrypted password). For example, this would be a valid $CVSROOT/CVSROOT/passwd file:
anonymous::pubcvs fish:rKa5jzULzmhOo:kfogel sussman:1sOp854gDF3DY
When the password field is omitted or empty, then the client’s authentication attempt will succeed with any password, including the empty string. However, the colon after the CVS username is always necessary, even if the password is empty.
CVS can also fall back to use system authentication.
When authenticating a password, the server first checks
for the user in the $CVSROOT/CVSROOT/passwd
file. If it finds the user, it will use that entry for
authentication as described above. But if it does not
find the user, or if the CVS passwd file
does not exist, then the server can try to authenticate
the username and password using the operating system’s
user-lookup routines (this "fallback" behavior can be
disabled by setting SystemAuth=no in the
CVS config file, see The CVSROOT/config configuration file).
The default fallback behavior is to look in
/etc/passwd for this system user unless your
system has PAM (Pluggable Authentication Modules)
and your CVS server executable was configured to
use it at compile time (using ./configure --enable-pam - see the
INSTALL file for more). In this case, PAM will be consulted instead.
This means that CVS can be configured to use any password
authentication source PAM can be configured to use (possibilities
include a simple UNIX password, NIS, LDAP, and others) in its
global configuration file (usually /etc/pam.conf
or possibly /etc/pam.d/cvs). See your PAM documentation
for more details on PAM configuration.
Note that PAM is an experimental feature in CVS and feedback is
encouraged. Please send a mail to one of the CVS mailing lists
(info-cvs@nongnu.org or bug-cvs@nongnu.org) if you use the
CVS PAM support.
WARNING: Using PAM gives the system administrator much more flexibility about how CVS users are authenticated but no more security than other methods. See below for more.
CVS needs an "auth", "account" and "session" module in the PAM configuration file. A typical PAM configuration would therefore have the following lines in /etc/pam.conf to emulate the standard CVS system /etc/passwd authentication:
cvs auth required pam_unix.so cvs account required pam_unix.so cvs session required pam_unix.so
The the equivalent /etc/pam.d/cvs would contain
auth required pam_unix.so account required pam_unix.so session required pam_unix.so
Some systems require a full path to the module so that pam_unix.so (Linux) would become something like /usr/lib/security/$ISA/pam_unix.so.1 (Sun Solaris). See the contrib/pam subdirectory of the CVS source distribution for further example configurations.
The PAM service name given above as "cvs" is just
the service name in the default configuration and can be
set using
./configure --with-hardcoded-pam-service-name=<pam-service-name>
before compiling. CVS can also be configured to use whatever
name it is invoked as as its PAM service name using
./configure --without-hardcoded-pam-service-name, but this
feature should not be used if you may not have control of the name
CVS will be invoked as.
Be aware, also, that falling back to system authentication might be a security risk: CVS operations would then be authenticated with that user’s regular login password, and the password flies across the network in plaintext. See Security considerations with password authentication for more on this. This may be more of a problem with PAM authentication because it is likely that the source of the system password is some central authentication service like LDAP which is also used to authenticate other services.
On the other hand, PAM makes it very easy to change your password regularly. If they are given the option of a one-password system for all of their activities, users are often more willing to change their password on a regular basis.
In the non-PAM configuration where the password is stored in the CVSROOT/passwd file, it is difficult to change passwords on a regular basis since only administrative users (or in some cases processes that act as an administrative user) are typically given access to modify this file. Either there needs to be some hand-crafted web page or set-uid program to update the file, or the update needs to be done by submitting a request to an administrator to perform the duty by hand. In the first case, having to remember to update a separate password on a periodic basis can be difficult. In the second case, the manual nature of the change will typically mean that the password will not be changed unless it is absolutely necessary.
Note that PAM administrators should probably avoid configuring one-time-passwords (OTP) for CVS authentication/authorization. If OTPs are desired, the administrator may wish to encourage the use of one of the other Client/Server access methods. See the section on see Remote repositories for a list of other methods.
Right now, the only way to put a password in the
CVS passwd file is to paste it there from
somewhere else. Someday, there may be a cvs
passwd command.
Unlike many of the files in $CVSROOT/CVSROOT, it is normal to edit the passwd file in-place, rather than via CVS. This is because of the possible security risks of having the passwd file checked out to people’s working copies. If you do want to include the passwd file in checkouts of $CVSROOT/CVSROOT, see The checkoutlist file.
To run a CVS command on a remote repository via
the password-authenticating server, one specifies the
pserver protocol, optional username, repository host, an
optional port number, and path to the repository. For example:
cvs -d :pserver:faun.example.org:/usr/local/cvsroot checkout someproj
or
CVSROOT=:pserver:bach@faun.example.org:2401/usr/local/cvsroot cvs checkout someproj
However, unless you’re connecting to a public-access
repository (i.e., one where that username doesn’t
require a password), you’ll need to supply a password or log in first.
Logging in verifies your password with the repository and stores it in a file.
It’s done with the login command, which will
prompt you interactively for the password if you didn’t supply one as part of
$CVSROOT:
cvs -d :pserver:bach@faun.example.org:/usr/local/cvsroot login CVS password:
or
cvs -d :pserver:bach:p4ss30rd@faun.example.org:/usr/local/cvsroot login
After you enter the password, CVS verifies it with
the server. If the verification succeeds, then that
combination of username, host, repository, and password
is permanently recorded, so future transactions with
that repository won’t require you to run cvs
login. (If verification fails, CVS will exit
complaining that the password was incorrect, and
nothing will be recorded.)
The records are stored, by default, in the file $HOME/.cvspass. That file’s format is human-readable, and to a degree human-editable, but note that the passwords are not stored in cleartext—they are trivially encoded to protect them from "innocent" compromise (i.e., inadvertent viewing by a system administrator or other non-malicious person).
You can change the default location of this file by
setting the CVS_PASSFILE environment variable.
If you use this variable, make sure you set it
before cvs login is run. If you were to
set it after running cvs login, then later
CVS commands would be unable to look up the
password for transmission to the server.
Once you have logged in, all CVS commands using that remote repository and username will authenticate with the stored password. So, for example
cvs -d :pserver:bach@faun.example.org:/usr/local/cvsroot checkout foo
should just work (unless the password changes on the
server side, in which case you’ll have to re-run
cvs login).
Note that if the ‘:pserver:’ were not present in
the repository specification, CVS would assume it
should use rsh to connect with the server
instead (see Connecting with rsh).
Of course, once you have a working copy checked out and are running CVS commands from within it, there is no longer any need to specify the repository explicitly, because CVS can deduce the repository from the working copy’s CVS subdirectory.
The password for a given remote repository can be
removed from the CVS_PASSFILE by using the
cvs logout command.
The passwords are stored on the client side in a trivial encoding of the cleartext, and transmitted in the same encoding. The encoding is done only to prevent inadvertent password compromises (i.e., a system administrator accidentally looking at the file), and will not prevent even a naive attacker from gaining the password.
The separate CVS password file (see Setting up the server for password authentication) allows people to use a different password for repository access than for login access. On the other hand, once a user has non-read-only access to the repository, she can execute programs on the server system through a variety of means. Thus, repository access implies fairly broad system access as well. It might be possible to modify CVS to prevent that, but no one has done so as of this writing.
Note that because the $CVSROOT/CVSROOT directory contains passwd and other files which are used to check security, you must control the permissions on this directory as tightly as the permissions on /etc. The same applies to the $CVSROOT directory itself and any directory above it in the tree. Anyone who has write access to such a directory will have the ability to become any user on the system. Note that these permissions are typically tighter than you would use if you are not using pserver.
In summary, anyone who gets the password gets repository access (which may imply some measure of general system access as well). The password is available to anyone who can sniff network packets or read a protected (i.e., user read-only) file. If you want real security, get Kerberos.
GSSAPI is a generic interface to network security systems such as Kerberos 5. If you have a working GSSAPI library, you can have CVS connect via a direct TCP connection, authenticating with GSSAPI.
To do this, CVS needs to be compiled with GSSAPI support; when configuring CVS it tries to detect whether GSSAPI libraries using Kerberos version 5 are present. You can also use the --with-gssapi flag to configure.
The connection is authenticated using GSSAPI, but the
message stream is not authenticated by default.
You must use the -a global option to request
stream authentication.
The data transmitted is not encrypted by
default. Encryption support must be compiled into both
the client and the server; use the
--enable-encrypt configure option to turn it on.
You must then use the -x global option to
request encryption.
GSSAPI connections are handled on the server side by
the same server which handles the password
authentication server; see Setting up the server for password authentication. If you are using a GSSAPI mechanism such as
Kerberos which provides for strong authentication, you
will probably want to disable the ability to
authenticate via cleartext passwords. To do so, create
an empty CVSROOT/passwd password file, and set
SystemAuth=no in the config file
(see The CVSROOT/config configuration file).
The GSSAPI server uses a principal name of cvs/hostname, where hostname is the canonical name of the server host. You will have to set this up as required by your GSSAPI mechanism.
To connect using GSSAPI, use the ‘:gserver:’ method. For example,
cvs -d :gserver:faun.example.org:/usr/local/cvsroot checkout foo
The easiest way to use Kerberos is to use the Kerberos
rsh, as described in Connecting with rsh.
The main disadvantage of using rsh is that all the data
needs to pass through additional programs, so it may be
slower. So if you have Kerberos installed you can
connect via a direct TCP connection,
authenticating with Kerberos.
This section concerns the Kerberos network security system, version 4. Kerberos version 5 is supported via the GSSAPI generic network security interface, as described in the previous section.
To do this, CVS needs to be compiled with Kerberos support; when configuring CVS it tries to detect whether Kerberos is present or you can use the --with-krb4 flag to configure.
The data transmitted is not encrypted by
default. Encryption support must be compiled into both
the client and server; use the
--enable-encryption configure option to turn it
on. You must then use the -x global option to
request encryption.
The CVS client will attempt to connect to port 1999 by default.
When you want to use CVS, get a ticket in the
usual way (generally kinit); it must be a ticket
which allows you to log into the server machine. Then
you are ready to go:
cvs -d :kserver:faun.example.org:/usr/local/cvsroot checkout foo
Previous versions of CVS would fall back to a connection via rsh; this version will not do so.
This access method allows you to connect to a
repository on your local disk via the remote protocol.
In other words it does pretty much the same thing as
:local:, but various quirks, bugs and the like are
those of the remote CVS rather than the local
CVS.
For day-to-day operations you might prefer either
:local: or :fork:, depending on your
preferences. Of course :fork: comes in
particularly handy in testing or
debugging cvs and the remote protocol.
Specifically, we avoid all of the network-related
setup/configuration, timeouts, and authentication
inherent in the other remote access methods but still
create a connection which uses the remote protocol.
To connect using the fork method, use
‘:fork:’ and the pathname to your local
repository. For example:
cvs -d :fork:/usr/local/cvsroot checkout foo
As with :ext:, the server is called ‘cvs’
by default, or the value of the CVS_SERVER
environment variable.
CVS can be configured to distribute usage across several CVS servers. This is accomplished by means of one or more write proxies, or secondary servers, for a single primary server.
When a CVS client accesses a secondary server and only sends read requests, then the secondary server handles the entire request. If the client sends any write requests, however, the secondary server asks the client to redirect its write request to the primary server, if the client supports redirect requests, and otherwise becomes a transparent proxy for the primary server, which actually handles the write request.
In this manner, any number of read-only secondary servers may be configured as write proxies for the primary server, effectively distributing the load from all read operations between the secondary servers and restricting the load on the primary server to write operations and pushing changes to the secondaries.
Primary servers will not automatically push changes to secondaries. This must be configured via loginfo, postadmin, posttag, & postwatch scripts (see The Trigger Scripts) like the following:
ALL rsync -gopr -essh ./ secondary:/cvsroot/%p &
You would probably actually want to lock directories for write on the secondary and for read on the primary before running the ‘rsync’ in the above example, but describing such a setup is beyond the scope of this document.
A secondary advantage of a write proxy setup is that users pointing at the secondary server can still execute fast read operations while on a network that connects to the primary over a slow link or even one where the link to the primary is periodically broken. Only write operations will require the network link to the primary.
To configure write proxies, the primary must be specified with the ‘PrimaryServer’ option in CVSROOT/config (see The CVSROOT/config configuration file). For the transparent proxy mode to work, all secondary servers must also be running the same version of the CVS server, or at least one that provides the same list of supported requests to the client as the primary server. This is not necessary for redirection.
Once a primary server is configured, secondary servers may be configured by:
--allow-root=secondary-cvsroot is passed to
all incovations of the secondary server if the path to the CVS
repository directory is different on the two servers and you wish to support
clients that do not handle the ‘Redirect’ resopnse (CVS 1.12.9 and earlier
clients do not handle the ‘Redirect’ response).
Please note, again, that writethrough proxy suport requires
--allow-root=secondary-cvsroot to be specified for all
incovations of the secondary server, not just ‘pserver’ invocations.
This may require a wrapper script for the CVS executable
on your server machine.
It is possible to grant read-only repository access to people using the password-authenticated server (see Direct connection with password authentication). (The other access methods do not have explicit support for read-only users because those methods all assume login access to the repository machine anyway, and therefore the user can do whatever local file permissions allow her to do.)
A user who has read-only access can do only those CVS operations which do not modify the repository, except for certain “administrative” files (such as lock files and the history file). It may be desirable to use this feature in conjunction with user-aliasing (see Setting up the server for password authentication).
Unlike with previous versions of CVS, read-only users should be able merely to read the repository, and not to execute programs on the server or otherwise gain unexpected levels of access. Or to be more accurate, the known holes have been plugged. Because this feature is new and has not received a comprehensive security audit, you should use whatever level of caution seems warranted given your attitude concerning security.
There are two ways to specify read-only access for a user: by inclusion, and by exclusion.
"Inclusion" means listing that user specifically in the $CVSROOT/CVSROOT/readers file, which is simply a newline-separated list of users. Here is a sample readers file:
melissa splotnik jrandom
(Don’t forget the newline after the last user.)
"Exclusion" means explicitly listing everyone who has write access—if the file
$CVSROOT/CVSROOT/writers
exists, then only those users listed in it have write access, and everyone else has read-only access (of course, even the read-only users still need to be listed in the CVS passwd file). The writers file has the same format as the readers file.
Note: if your CVS passwd file maps cvs users onto system users (see Setting up the server for password authentication), make sure you deny or grant read-only access using the cvs usernames, not the system usernames. That is, the readers and writers files contain cvs usernames, which may or may not be the same as system usernames.
Here is a complete description of the server’s behavior in deciding whether to grant read-only or read-write access:
If readers exists, and this user is listed in it, then she gets read-only access. Or if writers exists, and this user is NOT listed in it, then she also gets read-only access (this is true even if readers exists but she is not listed there). Otherwise, she gets full read-write access.
Of course there is a conflict if the user is listed in both files. This is resolved in the more conservative way, it being better to protect the repository too much than too little: such a user gets read-only access.
While running, the CVS server creates temporary directories. They are named
cvs-servpid
where pid is the process identification number of
the server.
They are located in the directory specified by
the ‘-T’ global option (see Global options),
the TMPDIR environment variable (see All environment variables which affect CVS),
or, failing that, /tmp.
In most cases the server will remove the temporary directory when it is done, whether it finishes normally or abnormally. However, there are a few cases in which the server does not or cannot remove the temporary directory, for example:
In cases such as this, you will need to manually remove the cvs-servpid directories. As long as there is no server running with process identification number pid, it is safe to do so.
Because renaming files and moving them between directories is somewhat inconvenient, the first thing you do when you start a new project should be to think through your file organization. It is not impossible to rename or move files, but it does increase the potential for confusion and CVS does have some quirks particularly in the area of renaming directories. See Moving and renaming files.
What to do next depends on the situation at hand.
The first step is to create the files inside the repository. This can be done in a couple of different ways.
When you begin using CVS, you will probably already have several
projects that can be
put under CVS control. In these cases the easiest way is to use the
import command. An example is probably the easiest way to
explain how to use it. If the files you want to install in
CVS reside in wdir, and you want them to appear in the
repository as $CVSROOT/yoyodyne/rdir, you can do this:
$ cd wdir $ cvs import -m "Imported sources" yoyodyne/rdir yoyo start
Unless you supply a log message with the ‘-m’ flag, CVS starts an editor and prompts for a message. The string ‘yoyo’ is a vendor tag, and ‘start’ is a release tag. They may fill no purpose in this context, but since CVS requires them they must be present. See Tracking third-party sources, for more information about them.
You can now verify that it worked, and remove your original source directory.
$ cd ..
$ cvs checkout yoyodyne/rdir # Explanation below
$ diff -r wdir yoyodyne/rdir
$ rm -r wdir
Erasing the original sources is a good idea, to make sure that you do not accidentally edit them in wdir, bypassing CVS. Of course, it would be wise to make sure that you have a backup of the sources before you remove them.
The checkout command can either take a module
name as argument (as it has done in all previous
examples) or a path name relative to $CVSROOT,
as it did in the example above.
It is a good idea to check that the permissions
CVS sets on the directories inside $CVSROOT
are reasonable, and that they belong to the proper
groups. See File permissions.
If some of the files you want to import are binary, you may want to use the wrappers features to specify which files are binary and which are not. See The cvswrappers file.
If you have a project which you are maintaining with another version control system, such as RCS, you may wish to put the files from that project into CVS, and preserve the revision history of the files.
If you have been using RCS, find the RCS files—usually a file named foo.c will have its RCS file in RCS/foo.c,v (but it could be other places; consult the RCS documentation for details). Then create the appropriate directories in CVS if they do not already exist. Then copy the files into the appropriate directories in the CVS repository (the name in the repository must be the name of the source file with ‘,v’ added; the files go directly in the appropriate directory of the repository, not in an RCS subdirectory). This is one of the few times when it is a good idea to access the CVS repository directly, rather than using CVS commands. Then you are ready to check out a new working directory.
The RCS file should not be locked when you move it into CVS; if it is, CVS will have trouble letting you operate on it.
Many version control systems have the ability to export RCS files in the standard format. If yours does, export the RCS files and then follow the above instructions.
Failing that, probably your best bet is to write a script that will check out the files one revision at a time using the command line interface to the other system, and then check the revisions into CVS. The sccs2rcs script mentioned below may be a useful example to follow.
There is a script in the contrib directory of the CVS source distribution called sccs2rcs which converts SCCS files to RCS files. Note: you must run it on a machine which has both SCCS and RCS installed, and like everything else in contrib it is unsupported (your mileage may vary).
There is a script in the contrib directory of the CVS source distribution called pvcs_to_rcs which converts PVCS archives to RCS files. You must run it on a machine which has both PVCS and RCS installed, and like everything else in contrib it is unsupported (your mileage may vary). See the comments in the script for details.
For a new project, the easiest thing to do is probably to create an empty directory structure, like this:
$ mkdir tc $ mkdir tc/man $ mkdir tc/testing
After that, you use the import command to create
the corresponding (empty) directory structure inside
the repository:
$ cd tc $ cvs import -m "Created directory structure" yoyodyne/dir yoyo start
This will add yoyodyne/dir as a directory under
$CVSROOT.
Use checkout to get the new project. Then, use add
to add files (and new directories) as needed.
$ cd .. $ cvs co yoyodyne/dir
Check that the permissions CVS sets on the
directories inside $CVSROOT are reasonable.
The next step is to define the module in the modules file. This is not strictly necessary, but modules can be convenient in grouping together related files and directories.
In simple cases these steps are sufficient to define a module.
$ cvs checkout CVSROOT/modules $ cd CVSROOT
tc yoyodyne/tc
$ cvs commit -m "Added the tc module." modules
$ cd .. $ cvs release -d CVSROOT
For many uses of CVS, one doesn’t need to worry
too much about revision numbers; CVS assigns
numbers such as 1.1, 1.2, and so on, and
that is all one needs to know. However, some people
prefer to have more knowledge and control concerning
how CVS assigns revision numbers.
If one wants to keep track of a set of revisions involving more than one file, such as which revisions went into a particular release, one uses a tag, which is a symbolic revision which can be assigned to a numeric revision in each file.
Each version of a file has a unique revision number. Revision numbers look like ‘1.1’, ‘1.2’, ‘1.3.2.2’ or even ‘1.3.2.2.4.5’. A revision number always has an even number of period-separated decimal integers. By default revision 1.1 is the first revision of a file. Each successive revision is given a new number by increasing the rightmost number by one. The following figure displays a few revisions, with newer revisions to the right.
+-----+ +-----+ +-----+ +-----+ +-----+
! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 !
+-----+ +-----+ +-----+ +-----+ +-----+
It is also possible to end up with numbers containing more than one period, for example ‘1.3.2.2’. Such revisions represent revisions on branches (see Branching and merging); such revision numbers are explained in detail in Branches and revisions.
A file can have several versions, as described above. Likewise, a software product can have several versions. A software product is often given a version number such as ‘4.1.1’.
Versions in the first sense are called revisions in this document, and versions in the second sense are called releases. To avoid confusion, the word version is almost never used in this document.
By default, CVS will assign numeric revisions by
leaving the first number the same and incrementing the
second number. For example, 1.1, 1.2,
1.3, etc.
When adding a new file, the second number will always
be one and the first number will equal the highest
first number of any file in that directory. For
example, the current directory contains files whose
highest numbered revisions are 1.7, 3.1,
and 4.12, then an added file will be given the
numeric revision 4.1.
(When using client/server CVS,
only files that are actually sent to the server are considered.)
Normally there is no reason to care
about the revision numbers—it is easier to treat them
as internal numbers that CVS maintains, and tags
provide a better way to distinguish between things like
release 1 versus release 2 of your product
(see Tags–Symbolic revisions). However, if you want to set the
numeric revisions, the ‘-r’ option to cvs
commit can do that. The ‘-r’ option implies the
‘-f’ option, in the sense that it causes the
files to be committed even if they are not modified.
For example, to bring all your files up to revision 3.0 (including those that haven’t changed), you might invoke:
$ cvs commit -r 3.0
Note that the number you specify with ‘-r’ must be larger than any existing revision number. That is, if revision 3.0 exists, you cannot ‘cvs commit -r 1.3’. If you want to maintain several releases in parallel, you need to use a branch (see Branching and merging).
The revision numbers live a life of their own. They need not have anything at all to do with the release numbers of your software product. Depending on how you use CVS the revision numbers might change several times between two releases. As an example, some of the source files that make up RCS 5.6 have the following revision numbers:
ci.c 5.21 co.c 5.9 ident.c 5.3 rcs.c 5.12 rcsbase.h 5.11 rcsdiff.c 5.10 rcsedit.c 5.11 rcsfcmp.c 5.9 rcsgen.c 5.10 rcslex.c 5.11 rcsmap.c 5.2 rcsutil.c 5.10
You can use the tag command to give a symbolic name to a
certain revision of a file. You can use the ‘-v’ flag to the
status command to see all tags that a file has, and
which revision numbers they represent. Tag names must
start with an uppercase or lowercase letter and can
contain uppercase and lowercase letters, digits,
‘-’, and ‘_’. The two tag names BASE
and HEAD are reserved for use by CVS. It
is expected that future names which are special to
CVS will be specially named, for example by
starting with ‘.’, rather than being named analogously to
BASE and HEAD, to avoid conflicts with
actual tag names.
You’ll want to choose some convention for naming tags,
based on information such as the name of the program
and the version number of the release. For example,
one might take the name of the program, immediately
followed by the version number with ‘.’ changed to
‘-’, so that CVS 1.9 would be tagged with the name
cvs1-9. If you choose a consistent convention,
then you won’t constantly be guessing whether a tag is
cvs-1-9 or cvs1_9 or what. You might
even want to consider enforcing your convention in the
taginfo file (see Taginfo).
The following example shows how you can add a tag to a file. The commands must be issued inside your working directory. That is, you should issue the command in the directory where backend.c resides.
$ cvs tag rel-0-4 backend.c
T backend.c
$ cvs status -v backend.c
===================================================================
File: backend.c Status: Up-to-date
Version: 1.4 Tue Dec 1 14:39:01 1992
RCS Version: 1.4 /u/cvsroot/yoyodyne/tc/backend.c,v
Sticky Tag: (none)
Sticky Date: (none)
Sticky Options: (none)
Existing Tags:
rel-0-4 (revision: 1.4)
For a complete summary of the syntax of cvs tag,
including the various options, see Quick reference to CVS commands.
There is seldom reason to tag a file in isolation. A more common use is to tag all the files that constitute a module with the same tag at strategic points in the development life-cycle, such as when a release is made.
$ cvs tag rel-1-0 . cvs tag: Tagging . T Makefile T backend.c T driver.c T frontend.c T parser.c
(When you give CVS a directory as argument, it generally applies the operation to all the files in that directory, and (recursively), to any subdirectories that it may contain. See Recursive behavior.)
The checkout command has a flag, ‘-r’, that lets you check out
a certain revision of a module. This flag makes it easy to
retrieve the sources that make up release 1.0 of the module ‘tc’ at
any time in the future:
$ cvs checkout -r rel-1-0 tc
This is useful, for instance, if someone claims that there is a bug in that release, but you cannot find the bug in the current working copy.
You can also check out a module as it was on any branch at any given date. See checkout options. When specifying ‘-r’ or ‘-D’ to any of these commands, you will need beware of sticky tags; see Sticky tags.
When you tag more than one file with the same tag you can think about the tag as "a curve drawn through a matrix of filename vs. revision number." Say we have 5 files with the following revisions:
file1 file2 file3 file4 file5
1.1 1.1 1.1 1.1 /--1.1* <-*- TAG
1.2*- 1.2 1.2 -1.2*-
1.3 \- 1.3*- 1.3 / 1.3
1.4 \ 1.4 / 1.4
\-1.5*- 1.5
1.6
At some time in the past, the * versions were tagged.
You can think of the tag as a handle attached to the curve
drawn through the tagged revisions. When you pull on
the handle, you get all the tagged revisions. Another
way to look at it is that you "sight" through a set of
revisions that is "flat" along the tagged revisions,
like this:
file1 file2 file3 file4 file5
1.1
1.2
1.1 1.3 _
1.1 1.2 1.4 1.1 /
1.2*----1.3*----1.5*----1.2*----1.1* (--- <--- Look here
1.3 1.6 1.3 \_
1.4 1.4
1.5
The example in the previous section demonstrates one of
the most common ways to choose which revisions to tag.
Namely, running the cvs tag command without
arguments causes CVS to select the revisions which
are checked out in the current working directory. For
example, if the copy of backend.c in working
directory was checked out from revision 1.4, then
CVS will tag revision 1.4. Note that the tag is
applied immediately to revision 1.4 in the repository;
tagging is not like modifying a file, or other
operations in which one first modifies the working
directory and then runs cvs commit to transfer
that modification to the repository.
One potentially surprising aspect of the fact that
cvs tag operates on the repository is that you
are tagging the checked-in revisions, which may differ
from locally modified files in your working directory.
If you want to avoid doing this by mistake, specify the
‘-c’ option to cvs tag. If there are any
locally modified files, CVS will abort with an
error before it tags any files:
$ cvs tag -c rel-0-4 cvs tag: backend.c is locally modified cvs [tag aborted]: correct the above errors first!
The cvs rtag command tags the repository as of a
certain date or time (or can be used to tag the latest
revision). rtag works directly on the
repository contents (it requires no prior checkout and
does not look for a working directory).
The following options specify which date or revision to tag. See Common command options, for a complete description of them.
-D dateTag the most recent revision no later than date.
-fOnly useful with the ‘-D’ or ‘-r’ flags. If no matching revision is found, use the most recent revision (instead of ignoring the file).
-r tag[:date]Tag the revision already tagged with tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See Common command options.
The cvs tag command also allows one to specify
files by revision or date, using the same ‘-r’,
‘-D’, and ‘-f’ options. However, this
feature is probably not what you want. The reason is
that cvs tag chooses which files to tag based on
the files that exist in the working directory, rather
than the files which existed as of the given tag/date.
Therefore, you are generally better off using cvs
rtag. The exceptions might be cases like:
cvs tag -r 1.4 stable backend.c
Normally one does not modify tags. They exist in order to record the history of the repository and so deleting them or changing their meaning would, generally, not be what you want.
However, there might be cases in which one uses a tag temporarily or accidentally puts one in the wrong place. Therefore, one might delete, move, or rename a tag.
WARNING: the commands in this section are dangerous; they permanently discard historical information and it can be difficult or impossible to recover from errors. If you are a CVS administrator, you may consider restricting these commands with the taginfo file (see Taginfo).
To delete a tag, specify the ‘-d’ option to either
cvs tag or cvs rtag. For example:
cvs rtag -d rel-0-4 tc
deletes the non-branch tag rel-0-4 from the module tc.
In the event that branch tags are encountered within the repository
with the given name, a warning message will be issued and the branch
tag will not be deleted. If you are absolutely certain you know what
you are doing, the -B option may be specified to allow deletion
of branch tags. In that case, any non-branch tags encountered will
trigger warnings and will not be deleted.
WARNING: Moving branch tags is very dangerous! If you think
you need the -B option, think again and ask your CVS
administrator about it (if that isn’t you). There is almost certainly
another way to accomplish what you want to accomplish.
When we say move a tag, we mean to make the same
name point to different revisions. For example, the
stable tag may currently point to revision 1.4
of backend.c and perhaps we want to make it
point to revision 1.6. To move a non-branch tag, specify the
‘-F’ option to either cvs tag or cvs
rtag. For example, the task just mentioned might be
accomplished as:
cvs tag -r 1.6 -F stable backend.c
If any branch tags are encountered in the repository
with the given name, a warning is issued and the branch
tag is not disturbed. If you are absolutely certain you
wish to move the branch tag, the -B option may be specified.
In that case, non-branch tags encountered with the given
name are ignored with a warning message.
WARNING: Moving branch tags is very dangerous! If you think you
need the -B option, think again and ask your CVS
administrator about it (if that isn’t you). There is almost certainly
another way to accomplish what you want to accomplish.
When we say rename a tag, we mean to make a
different name point to the same revisions as the old
tag. For example, one may have misspelled the tag name
and want to correct it (hopefully before others are
relying on the old spelling). To rename a tag, first
create a new tag using the ‘-r’ option to
cvs rtag, and then delete the old name. (Caution:
this method will not work with branch tags.)
This leaves the new tag on exactly the
same files as the old tag. For example:
cvs rtag -r old-name-0-4 rel-0-4 tc cvs rtag -d old-name-0-4 tc
The subject of exactly how tagging interacts with adding and removing files is somewhat obscure; for the most part CVS will keep track of whether files exist or not without too much fussing. By default, tags are applied to only files which have a revision corresponding to what is being tagged. Files which did not exist yet, or which were already removed, simply omit the tag, and CVS knows to treat the absence of a tag as meaning that the file didn’t exist as of that tag.
However, this can lose a small amount of information.
For example, suppose a file was added and then removed.
Then, if the tag is missing for that file, there is no
way to know whether the tag refers to the time before
the file was added, or the time after it was removed.
If you specify the ‘-r’ option to cvs rtag,
then CVS tags the files which have been removed,
and thereby avoids this problem. For example, one
might specify -r HEAD to tag the head.
On the subject of adding and removing files, the
cvs rtag command has a ‘-a’ option which
means to clear the tag from removed files that would
not otherwise be tagged. For example, one might
specify this option in conjunction with ‘-F’ when
moving a tag. If one moved a tag without ‘-a’,
then the tag in the removed files might still refer to
the old revision, rather than reflecting the fact that
the file had been removed. I don’t think this is
necessary if ‘-r’ is specified, as noted above.
Sometimes a working copy’s revision has extra data associated with it, for example it might be on a branch (see Branching and merging), or restricted to versions prior to a certain date by ‘checkout -D’ or ‘update -D’. Because this data persists – that is, it applies to subsequent commands in the working copy – we refer to it as sticky.
Most of the time, stickiness is an obscure aspect of CVS that you don’t need to think about. However, even if you don’t want to use the feature, you may need to know something about sticky tags (for example, how to avoid them!).
You can use the status command to see if any
sticky tags or dates are set:
$ cvs status driver.c
===================================================================
File: driver.c Status: Up-to-date
Version: 1.7.2.1 Sat Dec 5 19:35:03 1992
RCS Version: 1.7.2.1 /u/cvsroot/yoyodyne/tc/driver.c,v
Sticky Tag: rel-1-0-patches (branch: 1.7.2)
Sticky Date: (none)
Sticky Options: (none)
The sticky tags will remain on your working files until
you delete them with ‘cvs update -A’. The
‘-A’ option merges local changes into the version of the
file from the head of the trunk, removing any sticky tags,
dates, or options. See update—Bring work tree in sync with repository for more on the operation
of cvs update.
The most common use of sticky tags is to identify which
branch one is working on, as described in
Accessing branches. However, non-branch
sticky tags have uses as well. For example,
suppose that you want to avoid updating your working
directory, to isolate yourself from possibly
destabilizing changes other people are making. You
can, of course, just refrain from running cvs
update. But if you want to avoid updating only a
portion of a larger tree, then sticky tags can help.
If you check out a certain revision (such as 1.4) it
will become sticky. Subsequent cvs update
commands will
not retrieve the latest revision until you reset the
tag with cvs update -A. Likewise, use of the
‘-D’ option to update or checkout
sets a sticky date, which, similarly, causes that
date to be used for future retrievals.
People often want to retrieve an old version of
a file without setting a sticky tag. This can
be done with the ‘-p’ option to checkout or
update, which sends the contents of the file to
standard output. For example:
$ cvs update -p -r 1.1 file1 >file1 =================================================================== Checking out file1 RCS: /tmp/cvs-sanity/cvsroot/first-dir/Attic/file1,v VERS: 1.1 *************** $
However, this isn’t the easiest way, if you are asking
how to undo a previous checkin (in this example, put
file1 back to the way it was as of revision
1.1). In that case you are better off using the
‘-j’ option to update; for further
discussion see Merging differences between any two revisions.
CVS allows you to isolate changes onto a separate line of development, known as a branch. When you change files on a branch, those changes do not appear on the main trunk or other branches.
Later you can move changes from one branch to another
branch (or the main trunk) by merging. Merging
involves first running cvs update -j, to merge
the changes into the working directory.
You can then commit that revision, and thus effectively
copy the changes onto another branch.
Suppose that release 1.0 of tc has been made. You are continuing to develop tc, planning to create release 1.1 in a couple of months. After a while your customers start to complain about a fatal bug. You check out release 1.0 (see Tags–Symbolic revisions) and find the bug (which turns out to have a trivial fix). However, the current revision of the sources are in a state of flux and are not expected to be stable for at least another month. There is no way to make a bug fix release based on the newest sources.
The thing to do in a situation like this is to create a branch on the revision trees for all the files that make up release 1.0 of tc. You can then make modifications to the branch without disturbing the main trunk. When the modifications are finished you can elect to either incorporate them on the main trunk, or leave them on the branch.
You can create a branch with tag -b; for
example, assuming you’re in a working copy:
$ cvs tag -b rel-1-0-patches
This splits off a branch based on the current revisions in the working copy, assigning that branch the name ‘rel-1-0-patches’.
It is important to understand that branches get created in the repository, not in the working copy. Creating a branch based on current revisions, as the above example does, will not automatically switch the working copy to be on the new branch. For information on how to do that, see Accessing branches.
You can also create a branch without reference to any
working copy, by using rtag:
$ cvs rtag -b -r rel-1-0 rel-1-0-patches tc
‘-r rel-1-0’ says that this branch should be rooted at the revision that corresponds to the tag ‘rel-1-0’. It need not be the most recent revision – it’s often useful to split a branch off an old revision (for example, when fixing a bug in a past release otherwise known to be stable).
As with ‘tag’, the ‘-b’ flag tells
rtag to create a branch (rather than just a
symbolic revision name). Note that the numeric
revision number that matches ‘rel-1-0’ will
probably be different from file to file.
So, the full effect of the command is to create a new branch – named ‘rel-1-0-patches’ – in module ‘tc’, rooted in the revision tree at the point tagged by ‘rel-1-0’.
You can retrieve a branch in one of two ways: by checking it out fresh from the repository, or by switching an existing working copy over to the branch.
To check out a branch from the repository, invoke ‘checkout’ with the ‘-r’ flag, followed by the tag name of the branch (see Creating a branch):
$ cvs checkout -r rel-1-0-patches tc
Or, if you already have a working copy, you can switch it to a given branch with ‘update -r’:
$ cvs update -r rel-1-0-patches tc
or equivalently:
$ cd tc $ cvs update -r rel-1-0-patches
It does not matter if the working copy was originally on the main trunk or on some other branch – the above command will switch it to the named branch. And similarly to a regular ‘update’ command, ‘update -r’ merges any changes you have made, notifying you of conflicts where they occur.
Once you have a working copy tied to a particular branch, it remains there until you tell it otherwise. This means that changes checked in from the working copy will add new revisions on that branch, while leaving the main trunk and other branches unaffected.
To find out what branch a working copy is on, you can use the ‘status’ command. In its output, look for the field named ‘Sticky tag’ (see Sticky tags) – that’s CVS’s way of telling you the branch, if any, of the current working files:
$ cvs status -v driver.c backend.c
===================================================================
File: driver.c Status: Up-to-date
Version: 1.7 Sat Dec 5 18:25:54 1992
RCS Version: 1.7 /u/cvsroot/yoyodyne/tc/driver.c,v
Sticky Tag: rel-1-0-patches (branch: 1.7.2)
Sticky Date: (none)
Sticky Options: (none)
Existing Tags:
rel-1-0-patches (branch: 1.7.2)
rel-1-0 (revision: 1.7)
===================================================================
File: backend.c Status: Up-to-date
Version: 1.4 Tue Dec 1 14:39:01 1992
RCS Version: 1.4 /u/cvsroot/yoyodyne/tc/backend.c,v
Sticky Tag: rel-1-0-patches (branch: 1.4.2)
Sticky Date: (none)
Sticky Options: (none)
Existing Tags:
rel-1-0-patches (branch: 1.4.2)
rel-1-0 (revision: 1.4)
rel-0-4 (revision: 1.4)
Don’t be confused by the fact that the branch numbers for each file are different (‘1.7.2’ and ‘1.4.2’ respectively). The branch tag is the same, ‘rel-1-0-patches’, and the files are indeed on the same branch. The numbers simply reflect the point in each file’s revision history at which the branch was made. In the above example, one can deduce that ‘driver.c’ had been through more changes than ‘backend.c’ before this branch was created.
See Branches and revisions for details about how branch numbers are constructed.
Ordinarily, a file’s revision history is a linear series of increments (see Revision numbers):
+-----+ +-----+ +-----+ +-----+ +-----+
! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 !
+-----+ +-----+ +-----+ +-----+ +-----+
However, CVS is not limited to linear development. The revision tree can be split into branches, where each branch is a self-maintained line of development. Changes made on one branch can easily be moved back to the main trunk.
Each branch has a branch number, consisting of an odd number of period-separated decimal integers. The branch number is created by appending an integer to the revision number where the corresponding branch forked off. Having branch numbers allows more than one branch to be forked off from a certain revision.
All revisions on a branch have revision numbers formed by appending an ordinal number to the branch number. The following figure illustrates branching with an example.
+-------------+
Branch 1.2.2.3.2 -> ! 1.2.2.3.2.1 !
/ +-------------+
/
/
+---------+ +---------+ +---------+
Branch 1.2.2 -> _! 1.2.2.1 !----! 1.2.2.2 !----! 1.2.2.3 !
/ +---------+ +---------+ +---------+
/
/
+-----+ +-----+ +-----+ +-----+ +-----+
! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 ! <- The main trunk
+-----+ +-----+ +-----+ +-----+ +-----+
!
!
! +---------+ +---------+ +---------+
Branch 1.2.4 -> +---! 1.2.4.1 !----! 1.2.4.2 !----! 1.2.4.3 !
+---------+ +---------+ +---------+
The exact details of how the branch number is constructed is not something you normally need to be concerned about, but here is how it works: When CVS creates a branch number it picks the first unused even integer, starting with 2. So when you want to create a branch from revision 6.4 it will be numbered 6.4.2. All branch numbers ending in a zero (such as 6.4.0) are used internally by CVS (see Magic branch numbers). The branch 1.1.1 has a special meaning. See Tracking third-party sources.
This section describes a CVS feature called magic branches. For most purposes, you need not worry about magic branches; CVS handles them for you. However, they are visible to you in certain circumstances, so it may be useful to have some idea of how it works.
Externally, branch numbers consist of an odd number of dot-separated decimal integers. See Revision numbers. That is not the whole truth, however. For efficiency reasons CVS sometimes inserts an extra 0 in the second rightmost position (1.2.4 becomes 1.2.0.4, 8.9.10.11.12 becomes 8.9.10.11.0.12 and so on).
CVS does a pretty good job at hiding these so called magic branches, but in a few places the hiding is incomplete:
cvs log.
cvs
admin.
You can use the admin command to reassign a
symbolic name to a branch the way RCS expects it
to be. If R4patches is assigned to the branch
1.4.2 (magic branch number 1.4.0.2) in file
numbers.c you can do this:
$ cvs admin -NR4patches:1.4.2 numbers.c
It only works if at least one revision is already committed on the branch. Be very careful so that you do not assign the tag to the wrong number. (There is no way to see how the tag was assigned yesterday).
You can merge changes made on a branch into your working copy by giving
the ‘-j branchname’ flag to the update subcommand. With one
‘-j branchname’ option it merges the changes made between the
greatest common ancestor (GCA) of the branch and the destination revision (in
the simple case below the GCA is the point where the branch forked) and the
newest revision on that branch into your working copy.
The ‘-j’ stands for “join”.
Consider this revision tree:
+-----+ +-----+ +-----+ +-----+
! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 ! <- The main trunk
+-----+ +-----+ +-----+ +-----+
!
!
! +---------+ +---------+
Branch R1fix -> +---! 1.2.2.1 !----! 1.2.2.2 !
+---------+ +---------+
The branch 1.2.2 has been given the tag (symbolic name) ‘R1fix’. The following example assumes that the module ‘mod’ contains only one file, m.c.
$ cvs checkout mod # Retrieve the latest revision, 1.4 $ cvs update -j R1fix m.c # Merge all changes made on the branch, # i.e. the changes between revision 1.2 # and 1.2.2.2, into your working copy # of the file. $ cvs commit -m "Included R1fix" # Create revision 1.5.
A conflict can result from a merge operation. If that happens, you should resolve it before committing the new revision. See Conflicts example.
If your source files contain keywords (see Keyword substitution), you might be getting more conflicts than strictly necessary. See Merging and keywords, for information on how to avoid this.
The checkout command also supports the ‘-j branchname’ flag. The
same effect as above could be achieved with this:
$ cvs checkout -j R1fix mod $ cvs commit -m "Included R1fix"
It should be noted that update -j tagname will also work but may
not produce the desired result. See Merging can add or remove files, for more.
Continuing our example, the revision tree now looks like this:
+-----+ +-----+ +-----+ +-----+ +-----+
! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 ! <- The main trunk
+-----+ +-----+ +-----+ +-----+ +-----+
! *
! *
! +---------+ +---------+
Branch R1fix -> +---! 1.2.2.1 !----! 1.2.2.2 !
+---------+ +---------+
where the starred line represents the merge from the ‘R1fix’ branch to the main trunk, as just discussed.
Now suppose that development continues on the ‘R1fix’ branch:
+-----+ +-----+ +-----+ +-----+ +-----+
! 1.1 !----! 1.2 !----! 1.3 !----! 1.4 !----! 1.5 ! <- The main trunk
+-----+ +-----+ +-----+ +-----+ +-----+
! *
! *
! +---------+ +---------+ +---------+
Branch R1fix -> +---! 1.2.2.1 !----! 1.2.2.2 !----! 1.2.2.3 !
+---------+ +---------+ +---------+
and then you want to merge those new changes onto the
main trunk. If you just use the cvs update -j
R1fix m.c command again, CVS will attempt to
merge again the changes which you have already merged,
which can have undesirable side effects.
So instead you need to specify that you only want to merge the changes on the branch which have not yet been merged into the trunk. To do that you specify two ‘-j’ options, and CVS merges the changes from the first revision to the second revision. For example, in this case the simplest way would be
cvs update -j 1.2.2.2 -j R1fix m.c # Merge changes from 1.2.2.2 to the # head of the R1fix branch
The problem with this is that you need to specify the 1.2.2.2 revision manually. A slightly better approach might be to use the date the last merge was done:
cvs update -j R1fix:yesterday -j R1fix m.c
Better yet, tag the R1fix branch after every merge into the trunk, and then use that tag for subsequent merges:
cvs update -j merged_from_R1fix_to_trunk -j R1fix m.c
With two ‘-j revision’ flags, the update
(and checkout) command can merge the differences
between any two revisions into your working file.
$ cvs update -j 1.5 -j 1.3 backend.c
will undo all changes made between revision 1.3 and 1.5. Note the order of the revisions!
If you try to use this option when operating on multiple files, remember that the numeric revisions will probably be very different between the various files. You almost always use symbolic tags rather than revision numbers when operating on multiple files.
Specifying two ‘-j’ options can also undo file removals or additions. For example, suppose you have a file named file1 which existed as revision 1.1, and you then removed it (thus adding a dead revision 1.2). Now suppose you want to add it again, with the same contents it had previously. Here is how to do it:
$ cvs update -j 1.2 -j 1.1 file1 U file1 $ cvs commit -m test Checking in file1; /tmp/cvs-sanity/cvsroot/first-dir/file1,v <-- file1 new revision: 1.3; previous revision: 1.2 done $
If the changes which you are merging involve removing
or adding some files, update -j will reflect
such additions or removals.
For example:
cvs update -A touch a b c cvs add a b c ; cvs ci -m "added" a b c cvs tag -b branchtag cvs update -r branchtag touch d ; cvs add d rm a ; cvs rm a cvs ci -m "added d, removed a" cvs update -A cvs update -jbranchtag
After these commands are executed and a ‘cvs commit’ is done, file a will be removed and file d added in the main branch.
Note that using a single static tag (‘-j tagname’) rather than a dynamic tag (‘-j branchname’) to merge changes from a branch will usually not remove files which were removed on the branch since CVS does not automatically add static tags to dead revisions. The exception to this rule occurs when a static tag has been attached to a dead revision manually. Use the branch tag to merge all changes from the branch or use two static tags as merge endpoints to be sure that all intended changes are propagated in the merge.
If you merge files containing keywords (see Keyword substitution), you will normally get numerous conflicts during the merge, because the keywords are expanded differently in the revisions which you are merging.
Therefore, you will often want to specify the ‘-kk’ (see Substitution modes) switch to the merge command line. By substituting just the name of the keyword, not the expanded value of that keyword, this option ensures that the revisions which you are merging will be the same as each other, and avoid spurious conflicts.
For example, suppose you have a file like this:
+---------+
_! 1.1.2.1 ! <- br1
/ +---------+
/
/
+-----+ +-----+
! 1.1 !----! 1.2 !
+-----+ +-----+
and your working directory is currently on the trunk (revision 1.2). Then you might get the following results from a merge:
$ cat file1 key $Revision: 1.2 $ . . . $ cvs update -j br1 U file1 RCS file: /cvsroot/first-dir/file1,v retrieving revision 1.1 retrieving revision 1.1.2.1 Merging differences between 1.1 and 1.1.2.1 into file1 rcsmerge: warning: conflicts during merge $ cat file1 <<<<<<< file1 key $Revision: 1.2 $ ======= key $Revision: 1.1.2.1 $ >>>>>>> 1.1.2.1 . . .
What happened was that the merge tried to merge the
differences between 1.1 and 1.1.2.1 into your working
directory. So, since the keyword changed from
Revision: 1.1 to Revision: 1.1.2.1,
CVS tried to merge that change into your working
directory, which conflicted with the fact that your
working directory had contained Revision: 1.2.
Here is what happens if you had used ‘-kk’:
$ cat file1 key $Revision: 1.2 $ . . . $ cvs update -kk -j br1 U file1 RCS file: /cvsroot/first-dir/file1,v retrieving revision 1.1 retrieving revision 1.1.2.1 Merging differences between 1.1 and 1.1.2.1 into file1 $ cat file1 key $Revision$ . . .
What is going on here is that revision 1.1 and 1.1.2.1
both expand as plain Revision, and therefore
merging the changes between them into the working
directory need not change anything. Therefore, there
is no conflict.
WARNING: In versions of CVS prior to 1.12.2, there was a major problem with using ‘-kk’ on merges. Namely, ‘-kk’ overrode any default keyword expansion mode set in the archive file in the repository. This could, unfortunately for some users, cause data corruption in binary files (with a default keyword expansion mode set to ‘-kb’). Therefore, when a repository contained binary files, conflicts had to be dealt with manually rather than using ‘-kk’ in a merge command.
In CVS version 1.12.2 and later, the keyword expansion mode provided on the command line to any CVS command no longer overrides the ‘-kb’ keyword expansion mode setting for binary files, though it will still override other default keyword expansion modes. You can now safely merge using ‘-kk’ to avoid spurious conflicts on lines containing RCS keywords, even when your repository contains binary files.
Almost all of the subcommands of CVS work recursively when you specify a directory as an argument. For instance, consider this directory structure:
$HOME| +--tc| | +--CVS| (internal CVS files) +--Makefile+--backend.c+--driver.c+--frontend.c+--parser.c+--man| | | +--CVS| | (internal CVS files) | +--tc.1| +--testing| +--CVS| (internal CVS files) +--testpgm.t+--test2.t
If tc is the current working directory, the following is true:
cvs update testing/testpgm.t testing/test2.t
tc directory
If no arguments are given to update it will
update all files in the current working directory and
all its subdirectories. In other words, . is a
default argument to update. This is also true
for most of the CVS subcommands, not only the
update command.
The recursive behavior of the CVS subcommands can be turned off with the ‘-l’ option. Conversely, the ‘-R’ option can be used to force recursion if ‘-l’ is specified in ~/.cvsrc (see Default options and the ~/.cvsrc file).
$ cvs update -l # Don’t update files in subdirectories
In the course of a project, one will often add new files. Likewise with removing or renaming, or with directories. The general concept to keep in mind in all these cases is that instead of making an irreversible change you want CVS to record the fact that a change has taken place, just as with modifying an existing file. The exact mechanisms to do this in CVS vary depending on the situation.
To add a new file to a directory, follow these steps.
You can also use the add command to add a new
directory.
Unlike most other commands, the add command is
not recursive. You have to expcicitly name files and
directories that you wish to add to the repository.
However, each directory will need to be added
separately before you will be able to add new files
to those directories.
$ mkdir -p foo/bar $ cp ~/myfile foo/bar/myfile $ cvs add foo foo/bar $ cvs add foo/bar/myfile
-k kflag] [-m message] files … ¶Schedule files to be added to the repository.
The files or directories specified with add must
already exist in the current directory. To add a whole
new directory hierarchy to the source repository (for
example, files received from a third-party vendor), use
the import command instead. See import—Import sources into CVS, using vendor branches.
The added files are not placed in the source repository
until you use commit to make the change
permanent. Doing an add on a file that was
removed with the remove command will undo the
effect of the remove, unless a commit
command intervened. See Removing files, for an
example.
The ‘-k’ option specifies the default way that this file will be checked out; for more information see Substitution modes.
The ‘-m’ option specifies a description for the
file. This description appears in the history log (if
it is enabled, see The history file). It will also be
saved in the version history inside the repository when
the file is committed. The log command displays
this description. The description can be changed using
‘admin -t’. See admin—Administration front-end for RCS. If you omit the
‘-m description’ flag, an empty string will
be used. You will not be prompted for a description.
For example, the following commands add the file backend.c to the repository:
$ cvs add backend.c $ cvs commit -m "Early version. Not yet compilable." backend.c
When you add a file it is added only on the branch which you are working on (see Branching and merging). You can later merge the additions to another branch if you want (see Merging can add or remove files).
Directories change. New files are added, and old files disappear. Still, you want to be able to retrieve an exact copy of old releases.
Here is what you can do to remove a file, but remain able to retrieve old revisions:
status or update command. If you remove
the file without committing your changes, you will of
course not be able to retrieve the file as it was
immediately before you deleted it.
rm.
When you commit the removal of the file, CVS
records the fact that the file no longer exists. It is
possible for a file to exist on only some branches and
not on others, or to re-add another file with the same
name later. CVS will correctly create or not create
the file, based on the ‘-r’ and ‘-D’ options
specified to checkout or update.
Schedule file(s) to be removed from the repository (files which have not already been removed from the working directory are not processed). This command does not actually remove the file from the repository until you commit the removal. For a full list of options, see Quick reference to CVS commands.
Here is an example of removing several files:
$ cd test $ rm *.c $ cvs remove cvs remove: Removing . cvs remove: scheduling a.c for removal cvs remove: scheduling b.c for removal cvs remove: use 'cvs commit' to remove these files permanently $ cvs ci -m "Removed unneeded files" cvs commit: Examining . cvs commit: Committing .
As a convenience you can remove the file and cvs
remove it in one step, by specifying the ‘-f’
option. For example, the above example could also be
done like this:
$ cd test $ cvs remove -f *.c cvs remove: scheduling a.c for removal cvs remove: scheduling b.c for removal cvs remove: use 'cvs commit' to remove these files permanently $ cvs ci -m "Removed unneeded files" cvs commit: Examining . cvs commit: Committing .
If you execute remove for a file, and then
change your mind before you commit, you can undo the
remove with an add command.
$ ls CVS ja.h oj.c $ rm oj.c $ cvs remove oj.c cvs remove: scheduling oj.c for removal cvs remove: use 'cvs commit' to remove this file permanently $ cvs add oj.c U oj.c cvs add: oj.c, version 1.1.1.1, resurrected
If you realise your mistake before you run the
remove command you can use update to
resurrect the file:
$ rm oj.c $ cvs update oj.c cvs update: warning: oj.c was lost U oj.c
When you remove a file it is removed only on the branch which you are working on (see Branching and merging). You can later merge the removals to another branch if you want (see Merging can add or remove files).
In concept, removing directories is somewhat similar to removing files—you want the directory to not exist in your current working directories, but you also want to be able to retrieve old releases in which the directory existed.
The way that you remove a directory is to remove all
the files in it. You don’t remove the directory
itself; there is no way to do that.
Instead you specify the ‘-P’ option to
cvs update or cvs checkout,
which will cause CVS to remove empty
directories from working directories.
(Note that cvs export always removes empty directories.)
Probably the
best way to do this is to always specify ‘-P’; if
you want an empty directory then put a dummy file (for
example .keepme) in it to prevent ‘-P’ from
removing it.
Note that ‘-P’ is implied by the ‘-r’ or ‘-D’
options of checkout. This way,
CVS will be able to correctly create the directory
or not depending on whether the particular version you
are checking out contains any files in that directory.
Moving files to a different directory or renaming them is not difficult, but some of the ways in which this works may be non-obvious. (Moving or renaming a directory is even harder. See Moving and renaming directories.).
The examples below assume that the file old is renamed to new.
The normal way to move a file is to copy old to new, and then issue the normal CVS commands to remove old from the repository, and add new to it.
$ mv old new $ cvs remove old $ cvs add new $ cvs commit -m "Renamed old to new" old new
This is the simplest way to move a file, it is not
error-prone, and it preserves the history of what was
done. Note that to access the history of the file you
must specify the old or the new name, depending on what
portion of the history you are accessing. For example,
cvs log old will give the log up until the
time of the rename.
When new is committed its revision numbers will start again, usually at 1.1, so if that bothers you, use the ‘-r tag’ option to commit. For more information see Assigning revisions.
This method is more dangerous, since it involves moving files inside the repository. Read this entire section before trying it out!
$ cd $CVSROOT/dir $ mv old,v new,v
Advantages:
Disadvantages:
This way also involves direct modifications to the repository. It is safe, but not without drawbacks.
# Copy the RCS file inside the repository $ cd $CVSROOT/dir $ cp old,v new,v # Remove the old file $ cd ~/dir $ rm old $ cvs remove old $ cvs commit old # Remove all tags from new $ cvs update new $ cvs log new # Remember the non-branch tag names $ cvs tag -d tag1 new $ cvs tag -d tag2 new ...
By removing the tags you will be able to check out old revisions.
Advantages:
Disadvantages:
The normal way to rename or move a directory is to rename or move each file within it as described in The Normal way to Rename. Then check out with the ‘-P’ option, as described in Removing directories.
If you really want to hack the repository to rename or delete a directory in the repository, you can do it like this:
$ cd $CVSROOT/parent-dir $ mv old-dir new-dir
If someone had a working copy the CVS commands will cease to work for him, until he removes the directory that disappeared inside the repository.
It is almost always better to move the files in the directory instead of moving the directory. If you move the directory you are unlikely to be able to retrieve old releases correctly, since they probably depend on the name of the directories.
Once you have used CVS to store a version control history—what files have changed when, how, and by whom, there are a variety of mechanisms for looking through the history.
Whenever you commit a file you specify a log message.
To look through the log messages which have been
specified for every revision which has been committed,
use the cvs log command (see log—Print out history information for files).
You can use the history file (see The history file) to
log various CVS actions. To retrieve the
information from the history file, use the cvs
history command (see history—Show repository access history).
Note: you can control what is logged to this file by using the ‘LogHistory’ keyword in the CVSROOT/config file (see The CVSROOT/config configuration file).
You can customise CVS to log various kinds of actions, in whatever manner you choose. These mechanisms operate by executing a script at various times. The script might append a message to a file listing the information and the programmer who created it, or send mail to a group of developers, or, perhaps, post a message to a particular newsgroup. To log commits, use the loginfo file (see Loginfo), and to log tagging operations, use the taginfo file (see Taginfo).
To log commits, checkouts, exports, and tags,
respectively, you can also use the ‘-i’,
‘-o’, ‘-e’, and ‘-t’ options in the
modules file. For a more flexible way of giving
notifications to various users, which requires less in
the way of keeping centralised scripts up to date, use
the cvs watch add command (see Telling CVS to notify you); this command is useful even if you are not
using cvs watch on.
The most common use for CVS is to store text files. With text files, CVS can merge revisions, display the differences between revisions in a human-visible fashion, and other such operations. However, if you are willing to give up a few of these abilities, CVS can store binary files. For example, one might store a web site in CVS including both text files and binary images.
While the need to manage binary files may seem obvious if the files that you customarily work with are binary, putting them into version control does present some additional issues.
One basic function of version control is to show the
differences between two revisions. For example, if
someone else checked in a new version of a file, you
may wish to look at what they changed and determine
whether their changes are good. For text files,
CVS provides this functionality via the cvs
diff command. For binary files, it may be possible to
extract the two revisions and then compare them with a
tool external to CVS (for example, word processing
software often has such a feature). If there is no
such tool, one must track changes via other mechanisms,
such as urging people to write good log messages, and
hoping that the changes they actually made were the
changes that they intended to make.
Another ability of a version control system is the ability to merge two revisions. For CVS this happens in two contexts. The first is when users make changes in separate working directories (see Multiple developers). The second is when one merges explicitly with the ‘update -j’ command (see Branching and merging).
In the case of text files, CVS can merge changes made independently, and signal a conflict if the changes conflict. With binary files, the best that CVS can do is present the two different copies of the file, and leave it to the user to resolve the conflict. The user may choose one copy or the other, or may run an external merge tool which knows about that particular file format, if one exists. Note that having the user merge relies primarily on the user to not accidentally omit some changes, and thus is potentially error prone.
If this process is thought to be undesirable, the best choice may be to avoid merging. To avoid the merges that result from separate working directories, see the discussion of reserved checkouts (file locking) in Multiple developers. To avoid the merges resulting from branches, restrict use of branches.
There are two issues with using CVS to store binary files. The first is that CVS by default converts line endings between the canonical form in which they are stored in the repository (linefeed only), and the form appropriate to the operating system in use on the client (for example, carriage return followed by line feed for Windows NT).
The second is that a binary file might happen to contain data which looks like a keyword (see Keyword substitution), so keyword expansion must be turned off.
The ‘-kb’ option available with some CVS commands insures that neither line ending conversion nor keyword expansion will be done.
Here is an example of how you can create a new file using the ‘-kb’ flag:
$ echo '$Id$' > kotest $ cvs add -kb -m"A test file" kotest $ cvs ci -m"First checkin; contains a keyword" kotest
If a file accidentally gets added without ‘-kb’,
one can use the cvs admin command to recover.
For example:
$ echo '$Id$' > kotest $ cvs add -m"A test file" kotest $ cvs ci -m"First checkin; contains a keyword" kotest $ cvs admin -kb kotest $ cvs update -A kotest # For non-unix systems: # Copy in a good copy of the file from outside CVS $ cvs commit -m "make it binary" kotest
When you check in the file kotest the file is
not preserved as a binary file, because you did not
check it in as a binary file. The cvs
admin -kb command sets the default keyword
substitution method for this file, but it does not
alter the working copy of the file that you have. If you need to
cope with line endings (that is, you are using
CVS on a non-unix system), then you need to
check in a new copy of the file, as shown by the
cvs commit command above.
On unix, the cvs update -A command suffices.
(Note that you can use cvs log to determine the default keyword
substitution method for a file and cvs status to determine
the keyword substitution method for a working copy.)
However, in using cvs admin -k to change the
keyword expansion, be aware that the keyword expansion
mode is not version controlled. This means that, for
example, that if you have a text file in old releases,
and a binary file with the same name in new releases,
CVS provides no way to check out the file in text
or binary mode depending on what version you are
checking out. There is no good workaround for this
problem.
You can also set a default for whether cvs add
and cvs import treat a file as binary based on
its name; for example you could say that files who
names end in ‘.exe’ are binary. See The cvswrappers file.
There is currently no way to have CVS detect
whether a file is binary based on its contents. The
main difficulty with designing such a feature is that
it is not clear how to distinguish between binary and
non-binary files, and the rules to apply would vary
considerably with the operating system.
When more than one person works on a software project
things often get complicated. Often, two people try to
edit the same file simultaneously. One solution, known
as file locking or reserved checkouts, is
to allow only one person to edit each file at a time.
This is the only solution with some version control
systems, including RCS and SCCS. Currently
the usual way to get reserved checkouts with CVS
is the cvs admin -l command (see admin options). This is not as nicely integrated into
CVS as the watch features, described below, but it
seems that most people with a need for reserved
checkouts find it adequate.
As of CVS version 1.12.10, another technique for getting most of the
effect of reserved checkouts is to enable advisory locks. To enable advisory
locks, have all developers put "edit -c", "commit -c" in their
.cvsrc file, and turn on watches in the repository. This
prevents them from doing a cvs edit if anyone is
already editing the file. It also may
be possible to use plain watches together with suitable
procedures (not enforced by software), to avoid having
two people edit at the same time.
The default model with CVS is known as unreserved checkouts. In this model, developers can edit their own working copy of a file simultaneously. The first person that commits his changes has no automatic way of knowing that another has started to edit it. Others will get an error message when they try to commit the file. They must then use CVS commands to bring their working copy up to date with the repository revision. This process is almost automatic.
CVS also supports mechanisms which facilitate various kinds of communication, without actually enforcing rules like reserved checkouts do.
The rest of this chapter describes how these various models work, and some of the issues involved in choosing between them.
Based on what operations you have performed on a
checked out file, and what operations others have
performed to that file in the repository, one can
classify a file in a number of states. The states, as
reported by the status command, are:
The file is identical with the latest revision in the repository for the branch in use.
You have edited the file, and not yet committed your changes.
You have added the file with add, and not yet
committed your changes.
You have removed the file with remove, and not yet
committed your changes.
Someone else has committed a newer revision to the
repository. The name is slightly misleading; you will
ordinarily use update rather than
checkout to get that newer revision.
Like Needs Checkout, but the CVS server will send a patch rather than the entire file. Sending a patch or sending an entire file accomplishes the same thing.
Someone else has committed a newer revision to the repository, and you have also made modifications to the file.
A file with the same name as this new file has been added to the repository
from a second workspace. This file will need to be moved out of the way
to allow an update to complete.
This is like Locally Modified, except that a previous
update command gave a conflict. If you have not
already done so, you need to
resolve the conflict as described in Conflicts example.
CVS doesn’t know anything about this file. For
example, you have created a new file and have not run
add.
To help clarify the file status, status also
reports the Working revision which is the
revision that the file in the working directory derives
from, and the Repository revision which is the
latest revision in the repository for the branch in
use.
The ‘Commit Identifier’ reflects the unique commitid
of the commit.
The options to status are listed in
Quick reference to CVS commands. For information on its Sticky tag
and Sticky date output, see Sticky tags.
For information on its Sticky options output,
see the ‘-k’ option in update options.
You can think of the status and update
commands as somewhat complementary. You use
update to bring your files up to date, and you
can use status to give you some idea of what an
update would do (of course, the state of the
repository might change before you actually run
update). In fact, if you want a command to
display file status in a more brief format than is
displayed by the status command, you can invoke
$ cvs -n -q update
The ‘-n’ option means to not actually do the
update, but merely to display statuses; the ‘-q’
option avoids printing the name of each directory. For
more information on the update command, and
these options, see Quick reference to CVS commands.
When you want to update or merge a file, use the cvs update -d
command. For files that are not up to date this is roughly equivalent
to a checkout command: the newest revision of the file is
extracted from the repository and put in your working directory. The
-d option, not necessary with checkout, tells CVS
that you wish it to create directories added by other developers.
Your modifications to a file are never lost when you
use update. If no newer revision exists,
running update has no effect. If you have
edited the file, and a newer revision is available,
CVS will merge all changes into your working copy.
For instance, imagine that you checked out revision 1.4 and started
editing it. In the meantime someone else committed revision 1.5, and
shortly after that revision 1.6. If you run update on the file
now, CVS will incorporate all changes between revision 1.4 and 1.6 into
your file.
If any of the changes between 1.4 and 1.6 were made too
close to any of the changes you have made, an
overlap occurs. In such cases a warning is
printed, and the resulting file includes both
versions of the lines that overlap, delimited by
special markers.
See update—Bring work tree in sync with repository, for a complete description of the
update command.
Suppose revision 1.4 of driver.c contains this:
#include <stdio.h>
void main()
{
parse();
if (nerr == 0)
gencode();
else
fprintf(stderr, "No code generated.\n");
exit(nerr == 0 ? 0 : 1);
}
Revision 1.6 of driver.c contains this:
#include <stdio.h>
int main(int argc,
char **argv)
{
parse();
if (argc != 1)
{
fprintf(stderr, "tc: No args expected.\n");
exit(1);
}
if (nerr == 0)
gencode();
else
fprintf(stderr, "No code generated.\n");
exit(!!nerr);
}
Your working copy of driver.c, based on revision 1.4, contains this before you run ‘cvs update’:
#include <stdlib.h>
#include <stdio.h>
void main()
{
init_scanner();
parse();
if (nerr == 0)
gencode();
else
fprintf(stderr, "No code generated.\n");
exit(nerr == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
}
You run ‘cvs update’:
$ cvs update driver.c RCS file: /usr/local/cvsroot/yoyodyne/tc/driver.c,v retrieving revision 1.4 retrieving revision 1.6 Merging differences between 1.4 and 1.6 into driver.c rcsmerge warning: overlaps during merge cvs update: conflicts found in driver.c C driver.c
CVS tells you that there were some conflicts. Your original working file is saved unmodified in .#driver.c.1.4. The new version of driver.c contains this:
#include <stdlib.h>
#include <stdio.h>
int main(int argc,
char **argv)
{
init_scanner();
parse();
if (argc != 1)
{
fprintf(stderr, "tc: No args expected.\n");
exit(1);
}
if (nerr == 0)
gencode();
else
fprintf(stderr, "No code generated.\n");
<<<<<<< driver.c
exit(nerr == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
=======
exit(!!nerr);
>>>>>>> 1.6
}
Note how all non-overlapping modifications are incorporated in your working copy, and that the overlapping section is clearly marked with ‘<<<<<<<’, ‘=======’ and ‘>>>>>>>’.
You resolve the conflict by editing the file, removing the markers and the erroneous line. Suppose you end up with this file:
#include <stdlib.h>
#include <stdio.h>
int main(int argc,
char **argv)
{
init_scanner();
parse();
if (argc != 1)
{
fprintf(stderr, "tc: No args expected.\n");
exit(1);
}
if (nerr == 0)
gencode();
else
fprintf(stderr, "No code generated.\n");
exit(nerr == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
}
You can now go ahead and commit this as revision 1.7.
$ cvs commit -m "Initialise scanner. Use symbolic exit values." driver.c Checking in driver.c; /usr/local/cvsroot/yoyodyne/tc/driver.c,v <-- driver.c new revision: 1.7; previous revision: 1.6 done
For your protection, CVS will refuse to check in a file if a conflict occurred and you have not resolved the conflict. Currently to resolve a conflict, you must change the timestamp on the file. In previous versions of CVS, you also needed to insure that the file contains no conflict markers. Because your file may legitimately contain conflict markers (that is, occurrences of ‘>>>>>>> ’ at the start of a line that don’t mark a conflict), the current version of CVS will print a warning and proceed to check in the file.
If you use release 1.04 or later of pcl-cvs (a GNU Emacs front-end for CVS) you can use an Emacs package called emerge to help you resolve conflicts. See the documentation for pcl-cvs.
It is often useful to inform others when you commit a new revision of a file. The ‘-i’ option of the modules file, or the loginfo file, can be used to automate this process. See The modules file. See Loginfo. You can use these features of CVS to, for instance, instruct CVS to mail a message to all developers, or post a message to a local newsgroup.
If several developers try to run CVS at the same time, one may get the following message:
[11:43:23] waiting for bach's lock in /usr/local/cvsroot/foo
CVS will try again every 30 seconds, and either continue with the operation or print the message again, if it still needs to wait. If a lock seems to stick around for an undue amount of time, find the person holding the lock and ask them about the cvs command they are running. If they aren’t running a cvs command, look in the repository directory mentioned in the message and remove files which they own whose names start with #cvs.rfl, #cvs.wfl, or #cvs.lock.
Note that these locks are to protect CVS’s internal data structures and have no relationship to the word lock in the sense used by RCS—which refers to reserved checkouts (see Multiple developers).
Any number of people can be reading from a given repository at a time; only when someone is writing do the locks prevent other people from reading or writing.
One might hope for the following property:
If someone commits some changes in one cvs command, then an update by someone else will either get all the changes, or none of them.
but CVS does not have this property. For example, given the files
a/one.c a/two.c b/three.c b/four.c
if someone runs
cvs ci a/two.c b/three.c
and someone else runs cvs update at the same
time, the person running update might get only
the change to b/three.c and not the change to
a/two.c.
For many groups, use of CVS in its default mode is perfectly satisfactory. Users may sometimes go to check in a modification only to find that another modification has intervened, but they deal with it and proceed with their check in. Other groups prefer to be able to know who is editing what files, so that if two people try to edit the same file they can choose to talk about who is doing what when rather than be surprised at check in time. The features in this section allow such coordination, while retaining the ability of two developers to edit the same file at the same time.
For maximum benefit developers should use cvs
edit (not chmod) to make files read-write to
edit them, and cvs release (not rm) to
discard a working directory which is no longer in use,
but CVS is not able to enforce this behavior.
If a development team wants stronger enforcement of watches and all team members are using a CVS client version 1.12.10 or greater to access a CVS server version 1.12.10 or greater, they can enable advisory locks. To enable advisory locks, have all developers put "edit -c" and "commit -c" into all .cvsrc files, and make files default to read only by turning on watches or putting "cvs -r" into all .cvsrc files. This prevents multiple people from editing a file at the same time (unless explicitly overriden with ‘-f’).
To enable the watch features, you first specify that certain files are to be watched.
-lR] [files]… ¶Specify that developers should run cvs edit
before editing files. CVS will create working
copies of files read-only, to remind developers
to run the cvs edit command before working on
them.
If files includes the name of a directory, CVS
arranges to watch all files added to the corresponding
repository directory, and sets a default for files
added in the future; this allows the user to set
notification policies on a per-directory basis. The
contents of the directory are processed recursively,
unless the -l option is given.
The -R option can be used to force recursion if the -l
option is set in ~/.cvsrc (see Default options and the ~/.cvsrc file).
If files is omitted, it defaults to the current directory.
-lR] [files]… ¶Do not create files read-only on checkout; thus,
developers will not be reminded to use cvs edit
and cvs unedit.
The files and options are processed as for cvs
watch on.
You can tell CVS that you want to receive
notifications about various actions taken on a file.
You can do this without using cvs watch on for
the file, but generally you will want to use cvs
watch on, to remind developers to use the cvs edit
command.
-lR] [-a action]… [files]… ¶Add the current user to the list of people to receive notification of work done on files.
The -a option specifies what kinds of events CVS should notify
the user about. action is one of the following:
editAnother user has applied the cvs edit command (described
below) to a watched file.
commitAnother user has committed changes to one of the named files.
uneditAnother user has abandoned editing a file (other than by committing changes). They can do this in several ways, by:
cvs unedit command (described below) to the file
cvs release command (see release—Indicate that a directory is no longer in use) to the file’s parent directory
(or recursively to a directory more than one level up)
cvs update to recreate it
allAll of the above.
noneNone of the above. (This is useful with cvs edit,
described below.)
The -a option may appear more than once, or not at all. If
omitted, the action defaults to all.
The files and options are processed as for
cvs watch on.
-lR] [-a action]… [files]… ¶Remove a notification request established using cvs watch add;
the arguments are the same. If the -a option is present, only
watches for the specified actions are removed.
When the conditions exist for notification, CVS
calls the notify administrative file. Edit
notify as one edits the other administrative
files (see The administrative files). This
file follows the usual conventions for administrative
files (see The common syntax), where each line is a regular
expression followed by a command to execute. The
command should contain a single occurrence of ‘%s’
which will be replaced by the user to notify; the rest
of the information regarding the notification will be
supplied to the command on standard input. The
standard thing to put in the notify file is the
single line:
ALL mail %s -s "CVS notification"
This causes users to be notified by electronic mail.
Note that if you set this up in the straightforward way, users receive notifications on the server machine. One could of course write a notify script which directed notifications elsewhere, but to make this easy, CVS allows you to associate a notification address for each user. To do so create a file users in CVSROOT with a line for each user in the format user:value. Then instead of passing the name of the user to be notified to notify, CVS will pass the value (normally an email address on some other machine).
CVS does not notify you for your own changes. Currently this check is done based on whether the user name of the person taking the action which triggers notification matches the user name of the person getting notification. In fact, in general, the watches features only track one edit by each user. It probably would be more useful if watches tracked each working directory separately, so this behavior might be worth changing.
Since a file which is being watched is checked out
read-only, you cannot simply edit it. To make it
read-write, and inform others that you are planning to
edit it, use the cvs edit command. Some systems
call this a checkout, but CVS uses that term
for obtaining a copy of the sources (see Getting the source), an operation which those systems call a
get or a fetch.
-lR] [-a action]… [files]… ¶Prepare to edit the working files files. CVS makes the
files read-write, and notifies users who have requested
edit notification for any of files.
The cvs edit command accepts the same options as the
cvs watch add command, and establishes a temporary watch for the
user on files; CVS will remove the watch when files are
unedited or committed. If the user does not wish to
receive notifications, she should specify -a none.
The files and the options are processed as for the cvs
watch commands.
There are two additional options that cvs edit understands as of
CVS client and server versions 1.12.10 but cvs watch does not.
The first is -c, which causes cvs edit to fail if anyone else
is editing the file. This is probably only useful when ‘edit -c’ and
‘commit -c’ are specified in all developers’ .cvsrc files. This
behavior may be overriden this via the -f option, which overrides
-c and allows multiple edits to succeed.
Normally when you are done with a set of changes, you
use the cvs commit command, which checks in your
changes and returns the watched files to their usual
read-only state. But if you instead decide to abandon
your changes, or not to make any changes, you can use
the cvs unedit command.
-lR] [files]… ¶Abandon work on the working files files, and revert them to the
repository versions on which they are based. CVS makes those
files read-only for which users have requested notification using
cvs watch on. CVS notifies users who have requested unedit
notification for any of files.
The files and options are processed as for the
cvs watch commands.
If watches are not in use, the unedit command
probably does not work, and the way to revert to the
repository version is with the command cvs update -C file
(see update—Bring work tree in sync with repository).
The meaning is
not precisely the same; the latter may also
bring in some changes which have been made in the
repository since the last time you updated.
When using client/server CVS, you can use the
cvs edit and cvs unedit commands even if
CVS is unable to successfully communicate with the
server; the notifications will be sent upon the next
successful CVS command.
-lR] [files]… ¶List the users currently watching changes to files. The report includes the files being watched, and the mail address of each watcher.
The files and options are processed as for the
cvs watch commands.
-lR] [files]… ¶List the users currently working on files. The report includes the mail address of each user, the time when the user began working with the file, and the host and path of the working directory containing the file.
The files and options are processed as for the
cvs watch commands.
If you use the watch features on a repository, it creates CVS directories in the repository and stores the information about watches in that directory. If you attempt to use CVS 1.6 or earlier with the repository, you get an error message such as the following (all on one line):
cvs update: cannot open CVS/Entries for reading: No such file or directory
and your operation will likely be aborted. To use the
watch features, you must upgrade all copies of CVS
which use that repository in local or server mode. If
you cannot upgrade, use the watch off and
watch remove commands to remove all watches, and
that will restore the repository to a state which
CVS 1.6 can cope with.
Reserved and unreserved checkouts each have pros and cons. Let it be said that a lot of this is a matter of opinion or what works given different groups’ working styles, but here is a brief description of some of the issues. There are many ways to organise a team of developers. CVS does not try to enforce a certain organization. It is a tool that can be used in several ways.
Reserved checkouts can be very counter-productive. If two persons want to edit different parts of a file, there may be no reason to prevent either of them from doing so. Also, it is common for someone to take out a lock on a file, because they are planning to edit it, but then forget to release the lock.
People, especially people who are familiar with reserved checkouts, often wonder how often conflicts occur if unreserved checkouts are used, and how difficult they are to resolve. The experience with many groups is that they occur rarely and usually are relatively straightforward to resolve.
The rarity of serious conflicts may be surprising, until one realises that they occur only when two developers disagree on the proper design for a given section of code; such a disagreement suggests that the team has not been communicating properly in the first place. In order to collaborate under any source management regimen, developers must agree on the general design of the system; given this agreement, overlapping changes are usually straightforward to merge.
In some cases unreserved checkouts are clearly inappropriate. If no merge tool exists for the kind of file you are managing (for example word processor files or files edited by Computer Aided Design programs), and it is not desirable to change to a program which uses a mergeable data format, then resolving conflicts is going to be unpleasant enough that you generally will be better off to simply avoid the conflicts instead, by using reserved checkouts.
The watches features described above in Mechanisms to track who is editing files can be considered to be an intermediate model between reserved checkouts and unreserved checkouts. When you go to edit a file, it is possible to find out who else is editing it. And rather than having the system simply forbid both people editing the file, it can tell you what the situation is and let you figure out whether it is a problem in that particular case or not. Therefore, for some groups watches can be considered the best of both the reserved checkout and unreserved checkout worlds.
As of CVS client and server versions 1.12.10, you may also enable
advisory locks by putting ‘edit -c’ and ‘commit -c’ in all
developers’ .cvsrc files. After this is done, cvs edit
will fail if there are any other editors, and cvs commit will
fail if the committer has not registered to edit the file via cvs edit.
This is most effective in conjunction with files checked out read-only by
default, which may be enabled by turning on watches in the repository or by
putting ‘cvs -r’ in all .cvsrc files.
If you have read this far, you probably have a pretty good grasp on what CVS can do for you. This chapter talks a little about things that you still have to decide.
If you are doing development on your own using CVS you could probably skip this chapter. The questions this chapter takes up become more important when more than one person is working in a repository.
Your group should decide which policy to use regarding commits. Several policies are possible, and as your experience with CVS grows you will probably find out what works for you.
If you commit files too quickly you might commit files that do not even compile. If your partner updates his working sources to include your buggy file, he will be unable to compile the code. On the other hand, other persons will not be able to benefit from the improvements you make to the code if you commit very seldom, and conflicts will probably be more common.
It is common to only commit files after making sure that they can be compiled. Some sites require that the files pass a test suite. Policies like this can be enforced using the commitinfo file (see Commitinfo), but you should think twice before you enforce such a convention. By making the development environment too controlled it might become too regimented and thus counter-productive to the real goal, which is to get software written.
As long as you edit source files inside a working directory you can always find out the state of your files via ‘cvs status’ and ‘cvs log’. But as soon as you export the files from your development environment it becomes harder to identify which revisions they are.
CVS can use a mechanism known as keyword
substitution (or keyword expansion) to help
identifying the files. Embedded strings of the form
$keyword$ and
$keyword:…$ in a file are replaced
with strings of the form
$keyword:value$ whenever you obtain
a new revision of the file.
This is a list of the keywords:
$Author$ ¶The login name of the user who checked in the revision.
$CVSHeader$ ¶A standard header (similar to $Header$, but with the CVS root stripped off). It contains the relative pathname of the RCS file to the CVS root, the revision number, the date (UTC), the author, the state, and the locker (if locked). Files will normally never be locked when you use CVS.
Note that this keyword has only been recently
introduced to CVS and may cause problems with
existing installations if $CVSHeader$ is already
in the files for a different purpose. This keyword may
be excluded using the KeywordExpand=eCVSHeader
in the CVSROOT/config file.
See Configuring Keyword Expansion for more details.
$Date$ ¶The date and time (UTC) the revision was checked in.
$Mdocdate$ ¶The date (UTC) the revision was checked in, in a format suitable for the Berkeley mdoc macro processing.
$Mdocdate: January 30 2021 $
$Header$ ¶A standard header containing the full pathname of the RCS file, the revision number, the date (UTC), the author, the state, and the locker (if locked). Files will normally never be locked when you use CVS.
$Id$ ¶Same as $Header$, except that the RCS
filename is without a path.
$Name$ ¶Tag name used to check out this file. The keyword is
expanded only if one checks out with an explicit tag
name. For example, when running the command cvs
co -r first, the keyword expands to ‘Name: first’.
$Locker$ ¶The login name of the user who locked the revision
(empty if not locked, which is the normal case unless
cvs admin -l is in use).
$Log$ ¶The log message supplied during commit, preceded by a
header containing the RCS filename, the revision
number, the author, and the date (UTC). Existing log
messages are not replaced. Instead, the new log
message is inserted after $Log:…$.
By default, each new line is prefixed with the same string which
precedes the $Log$ keyword, unless it exceeds the
MaxCommentLeaderLength set in CVSROOT/config.
For example, if the file contains:
/* Here is what people have been up to: * * $Log: frob.c,v $ * Revision 1.1 1997/01/03 14:23:51 joe * Add the superfrobnicate option * */
then additional lines which are added when expanding
the $Log$ keyword will be preceded by ‘ * ’.
Unlike previous versions of CVS and RCS, the
comment leader from the RCS file is not used.
The $Log$ keyword is useful for
accumulating a complete change log in a source file,
but for several reasons it can be problematic.
If the prefix of the $Log$ keyword turns out to be
longer than the CVSROOT/config setting MaxCommentLeaderLength,
CVS will skip expansion of this
keyword unless UseArchiveCommentLeader is also set in
CVSROOT/config and a ‘comment leader’ is set in the RCS archive
file, in which case the comment leader will be used instead. For more on
setting the comment leader in the RCS archive file, See admin—Administration front-end for RCS. For more
on configuring the default $Log$ substitution
behavior, See The CVSROOT/config configuration file.
$RCSfile$ ¶The name of the RCS file without a path.
$Revision$ ¶The revision number assigned to the revision.
$Source$ ¶The full pathname of the RCS file.
$State$ ¶The state assigned to the revision. States can be
assigned with cvs admin -s—see admin options.
Local keyword ¶The LocalKeyword option in the CVSROOT/config file
may be used to specify a local keyword which is to be
used as an alias for one of the keywords: $Id$,
$Header$, or $CVSHeader$. For
example, if the CVSROOT/config file contains
a line with LocalKeyword=MYBSD=CVSHeader, then a
file with the local keyword $MYBSD$ will be
expanded as if it were a $CVSHeader$ keyword. If
the src/frob.c file contained this keyword, it might
look something like this:
/* * $MYBSD: src/frob.c,v 1.1 2003/05/04 09:27:45 john Exp $ */
Many repositories make use of a such a “local
keyword” feature. An old patch to CVS provided
the LocalKeyword feature using a tag=
option and called this the “custom tag” or “local
tag” feature. It was used in conjunction with the
what they called the tagexpand= option. In
CVS this other option is known as the
KeywordExpand option.
See Configuring Keyword Expansion for more
details.
Examples from popular projects include: $FreeBSD$, $NetBSD$, $OpenBSD$, $XFree86$, $Xorg$.
The advantage of this is that you can include your local version information in a file using this local keyword without disrupting the upstream version information (which may be a different local keyword or a standard keyword). Allowing bug reports and the like to more properly identify the source of the original bug to the third-party and reducing the number of conflicts that arise during an import of a new version.
All keyword expansion except the local keyword may be
disabled using the KeywordExpand option in
the CVSROOT/config file—see
Configuring Keyword Expansion for more details.
To include a keyword string you simply include the
relevant text string, such as $Id$, inside the
file, and commit the file. CVS will automatically (Or,
more accurately, as part of the update run that
automatically happens after a commit.)
expand the string as part of the commit operation.
It is common to embed the $Id$ string in
the source files so that it gets passed through to
generated files. For example, if you are managing
computer program source code, you might include a
variable which is initialised to contain that string.
Or some C compilers may provide a #pragma ident
directive. Or a document management system might
provide a way to pass a string through to generated
files.
The ident command (which is part of the RCS
package) can be used to extract keywords and their
values from a file. This can be handy for text files,
but it is even more useful for extracting keywords from
binary files.
$ ident samp.c
samp.c:
$Id: samp.c,v 1.5 1993/10/19 14:57:32 ceder Exp $
$ gcc samp.c
$ ident a.out
a.out:
$Id: samp.c,v 1.5 1993/10/19 14:57:32 ceder Exp $
SCCS is another popular revision control system.
It has a command, what, which is very similar to
ident and used for the same purpose. Many sites
without RCS have SCCS. Since what
looks for the character sequence @(#) it is
easy to include keywords that are detected by either
command. Simply prefix the keyword with the
magic SCCS phrase, like this:
static char *id="@(#) $Id: ab.c,v 1.5 1993/10/19 14:57:32 ceder Exp $";
Keyword substitution has its disadvantages. Sometimes you might want the literal text string ‘$Author$’ to appear inside a file without CVS interpreting it as a keyword and expanding it into something like ‘$Author: ceder $’.
There is unfortunately no way to selectively turn off keyword substitution. You can use ‘-ko’ (see Substitution modes) to turn off keyword substitution entirely.
In many cases you can avoid using keywords in
the source, even though they appear in the final
product. For example, the source for this manual
contains ‘$@asis{}Author$’ whenever the text
‘$Author$’ should appear. In nroff
and troff you can embed the null-character
\& inside the keyword for a similar effect.
It is also possible to specify an explicit list of
keywords to include or exclude using the
KeywordExpand option in the
CVSROOT/config file–see Configuring Keyword Expansion
for more details. This feature is intended primarily
for use with the LocalKeyword option–see
Keyword List.
Each file has a stored default substitution mode, and
each working directory copy of a file also has a
substitution mode. The former is set by the ‘-k’
option to cvs add and cvs admin; the
latter is set by the ‘-k’ or ‘-A’ options to cvs
checkout or cvs update.
cvs diff and cvs rdiff also
have ‘-k’ options.
For some examples,
see Handling binary files, and Merging and keywords.
The modes available are:
Generate keyword strings using the default form, e.g.
$Revision: 5.7 $ for the Revision
keyword.
Like ‘-kkv’, except that a locker’s name is always
inserted if the given revision is currently locked.
The locker’s name is only relevant if cvs admin
-l is in use.
Generate only keyword names in keyword strings; omit
their values. For example, for the Revision
keyword, generate the string $Revision$
instead of $Revision: 5.7 $. This option
is useful to ignore differences due to keyword
substitution when comparing different revisions of a
file (see Merging and keywords).
Generate the old keyword string, present in the working
file just before it was checked in. For example, for
the Revision keyword, generate the string
$Revision: 1.1 $ instead of
$Revision: 5.7 $ if that is how the
string appeared when the file was checked in.
Like ‘-ko’, but also inhibit conversion of line
endings between the canonical form in which they are
stored in the repository (linefeed only), and the form
appropriate to the operating system in use on the
client. For systems, like unix, which use linefeed
only to terminate lines, this is very similar to
‘-ko’. For more information on binary files, see
Handling binary files. In CVS version 1.12.2 and later
‘-kb’, as set by cvs add, cvs admin, or
cvs import may not be overridden by a ‘-k’ option
specified on the command line.
Generate only keyword values for keyword strings. For
example, for the Revision keyword, generate the string
5.7 instead of $Revision: 5.7 $.
This can help generate files in programming languages
where it is hard to strip keyword delimiters like
$Revision: $ from a string. However,
further keyword substitution cannot be performed once
the keyword names are removed, so this option should be
used with care.
One often would like to use ‘-kv’ with cvs
export—see export—Export sources from CVS, similar to checkout. But be aware that doesn’t
handle an export containing binary files correctly.
In a repository that includes third-party software on vendor branches, it is sometimes helpful to configure CVS to use a local keyword instead of the standard $Id$ or $Header$ keywords. Examples from real projects include $Xorg$, $XFree86$, $FreeBSD$, $NetBSD$, $OpenBSD$, and even $dotat$. The advantage of this is that you can include your local version information in a file using this local keyword (sometimes called a “custom tag” or a “local tag”) without disrupting the upstream version information (which may be a different local keyword or a standard keyword). In these cases, it is typically desirable to disable the expansion of all keywords except the configured local keyword.
The KeywordExpand option in the
CVSROOT/config file is intended to allow for the
either the explicit exclusion of a keyword or list of
keywords, or for the explicit inclusion of a keyword or
a list of keywords. This list may include the
LocalKeyword that has been configured.
The KeywordExpand option is followed by
= and the next character may either be i
to start an inclusion list or e to start an
exclusion list. If the following lines were added to
the CVSROOT/config file:
# Add a "MyBSD" keyword and restrict keyword
# expansion
LocalKeyword=MyBSD=CVSHeader
KeywordExpand=iMyBSD
then only the $MyBSD$ keyword would be expanded. A list may be used. The this example:
# Add a "MyBSD" keyword and restrict keyword expansion
# to the MyBSD, Name, Date and Mdocdate keywords.
LocalKeyword=MyBSD=CVSHeader
KeywordExpand=iMyBSD,Name,Date,Mdocdate
would allow $MyBSD$, $Name$, $Mdocdate and $Date$ to be expanded.
It is also possible to configure an exclusion list using the following:
# Do not expand the non-RCS keyword CVSHeader
KeywordExpand=eCVSHeader
This allows CVS to ignore the recently introduced $CVSHeader$ keyword and retain all of the others. The exclusion entry could also contain the standard RCS keyword list, but this could be confusing to users that expect RCS keywords to be expanded, so care should be taken to properly set user expectations for a repository that is configured in that manner.
If there is a desire to not have any RCS keywords
expanded and not use the -ko flags everywhere,
an administrator may disable all keyword expansion
using the CVSROOT/config line:
# Do not expand any RCS keywords KeywordExpand=i
this could be confusing to users that expect RCS keywords like $Id$ to be expanded properly, so care should be taken to properly set user expectations for a repository so configured.
It should be noted that a patch to provide both the
KeywordExpand and LocalKeyword features
has been around a long time. However, that patch
implemented these features using tag= and
tagexpand= keywords and those keywords are NOT
recognised.
The $Log$ keyword is somewhat
controversial. As long as you are working on your
development system the information is easily accessible
even if you do not use the $Log$
keyword—just do a cvs log. Once you export
the file the history information might be useless
anyhow.
A more serious concern is that CVS is not good at
handling $Log$ entries when a branch is
merged onto the main trunk. Conflicts often result
from the merging operation.
People also tend to "fix" the log entries in the file
(correcting spelling mistakes and maybe even factual
errors). If that is done the information from
cvs log will not be consistent with the
information inside the file. This may or may not be a
problem in real life.
It has been suggested that the $Log$
keyword should be inserted last in the file, and
not in the files header, if it is to be used at all.
That way the long list of change messages will not
interfere with everyday source file browsing.
If you modify a program to better fit your site, you probably want to include your modifications when the next release of the program arrives. CVS can help you with this task.
In the terminology used in CVS, the supplier of the program is called a vendor. The unmodified distribution from the vendor is checked in on its own branch, the vendor branch. CVS reserves branch 1.1.1 for this use.
When you modify the source and commit it, your revision will end up on the main trunk. When a new release is made by the vendor, you commit it on the vendor branch and copy the modifications onto the main trunk.
Use the import command to create and update
the vendor branch. When you import a new file,
(usually) the vendor branch is made the ‘head’ revision, so
anyone that checks out a copy of the file gets that
revision. When a local modification is committed it is
placed on the main trunk, and made the ‘head’
revision.
Use the import command to check in the sources
for the first time. When you use the import
command to track third-party sources, the vendor
tag and release tags are useful. The
vendor tag is a symbolic name for the branch
(which is always 1.1.1, unless you use the ‘-b
branch’ flag—see Multiple vendor branches.). The
release tags are symbolic names for a particular
release, such as ‘FSF_0_04’.
Note that import does not change the
directory in which you invoke it. In particular, it
does not set up that directory as a CVS working
directory; if you want to work with the sources import
them first and then check them out into a different
directory (see Getting the source).
Suppose you have the sources to a program called
wdiff in a directory wdiff-0.04,
and are going to make private modifications that you
want to be able to use even when new releases are made
in the future. You start by importing the source to
your repository:
$ cd wdiff-0.04 $ cvs import -m "Import of FSF v. 0.04" fsf/wdiff FSF_DIST WDIFF_0_04
The vendor tag is named ‘FSF_DIST’ in the above example, and the only release tag assigned is ‘WDIFF_0_04’.
When a new release of the source arrives, you import it into the
repository with the same import command that you used to set up
the repository in the first place. The only difference is that you
specify a different release tag this time:
$ tar xfz wdiff-0.05.tar.gz $ cd wdiff-0.05 $ cvs import -m "Import of FSF v. 0.05" fsf/wdiff FSF_DIST WDIFF_0_05
WARNING: If you use a release tag that already exists in one of the repository archives, files removed by an import may not be detected.
For files that have not been modified locally, the newly created
revision becomes the head revision. If you have made local
changes, import will warn you that you must merge the changes
into the main trunk, and tell you to use ‘checkout -j’ to do so:
$ cvs checkout -jFSF_DIST:yesterday -jFSF_DIST wdiff
The above command will check out the latest revision of ‘wdiff’, merging the changes made on the vendor branch ‘FSF_DIST’ since yesterday into the working copy. If any conflicts arise during the merge they should be resolved in the normal way (see Conflicts example). Then, the modified files may be committed.
However, it is much better to use the two release tags rather than using a date on the branch as suggested above:
$ cvs checkout -jWDIFF_0_04 -jWDIFF_0_05 wdiff
The reason this is better is that
using a date, as suggested above, assumes that you do
not import more than one release of a product per day.
More importantly, using the release tags allows CVS to detect files
that were removed between the two vendor releases and mark them for
removal. Since import has no way to detect removed files, you
should do a merge like this even if import doesn’t tell you to.
You can also revert local changes completely and return
to the latest vendor release by changing the ‘head’
revision back to the vendor branch on all files. This
does, however, produce weird results if you should ever
edit this file again, for anyone looking at the output
from the log command or CVSweb. To fix this,
first commit a revision of the file which equals the
vendor branch, then use admin ‘-b’. For
example, if you have a checked-out copy of the sources
in ~/work.d/wdiff, and you want to revert to the
vendor’s version for all the files in that directory,
you would type:
$ cd ~/work.d/wdiff $ cvs admin -bFSF_DIST .
You must specify the ‘-bFSF_DIST’ without any space after the ‘-b’. See admin options.
Use the ‘-k’ wrapper option to tell import which files are binary. See The cvswrappers file.
The sources which you are importing may contain keywords (see Keyword substitution). For example, the vendor may use CVS or some other system which uses similar keyword expansion syntax. If you just import the files in the default fashion, then the keyword expansions supplied by the vendor will be replaced by keyword expansions supplied by your own copy of CVS. It may be more convenient to maintain the expansions supplied by the vendor, so that this information can supply information about the sources that you imported from the vendor.
To maintain the keyword expansions supplied by the
vendor, supply the ‘-ko’ option to cvs
import the first time you import the file.
This will turn off keyword expansion
for that file entirely, so if you want to be more
selective you’ll have to think about what you want
and use the ‘-k’ option to cvs update or
cvs admin as appropriate.
All the examples so far assume that there is only one vendor from which you are getting sources. In some situations you might get sources from a variety of places. For example, suppose that you are dealing with a project where many different people and teams are modifying the software. There are a variety of ways to handle this, but in some cases you have a bunch of source trees lying around and what you want to do more than anything else is just to all put them in CVS so that you at least have them in one place.
For handling situations in which there may be more than
one vendor, you may specify the ‘-b’ option to
cvs import. It takes as an argument the vendor
branch to import to. The default is ‘-b 1.1.1’.
Vendor branches can only be in the format 1.1.x where ‘x’ is an uneven number, because branch tags use even numbers.
For example, suppose that there are two teams, the red team and the blue team, that are sending you sources. You want to import the red team’s efforts to branch 1.1.1 and use the vendor tag RED. You want to import the blue team’s efforts to branch 1.1.3 and use the vendor tag BLUE. So the commands you might use are:
$ cvs import dir RED RED_1-0 $ cvs import -b 1.1.3 dir BLUE BLUE_1-5
Note that if your vendor tag does not match your ‘-b’ option, CVS will not detect this case! For example,
$ cvs import -b 1.1.3 dir RED RED_1-0
Be careful; this kind of mismatch is sure to sow confusion or worse. I can’t think of a useful purpose for the ability to specify a mismatch here, but if you discover such a use, don’t. CVS is likely to make this an error in some future release.
As mentioned in the introduction, CVS does not contain software for building your software from source code. This section describes how various aspects of your build system might interact with CVS.
One common question, especially from people who are
accustomed to RCS, is how to make their build get
an up to date copy of the sources. The answer to this
with CVS is two-fold. First of all, since
CVS itself can recurse through directories, there
is no need to modify your Makefile (or whatever
configuration file your build tool uses) to make sure
each file is up to date. Instead, just use two
commands, first cvs -q update and then
make or whatever the command is to invoke your
build tool. Secondly, you do not necessarily
want to get a copy of a change someone else made
until you have finished your own work. One suggested
approach is to first update your sources, then
implement, build and
test the change you were thinking of, and then commit
your sources (updating first if necessary). By
periodically (in between changes, using the approach
just described) updating your entire tree, you ensure
that your sources are sufficiently up to date.
One common need is to record which versions of which
source files went into a particular build. This kind
of functionality is sometimes called bill of
materials or something similar. The best way to do
this with CVS is to use the tag command to
record which versions went into a given build
(see Tags–Symbolic revisions).
Using CVS in the most straightforward manner possible, each developer will have a copy of the entire source tree which is used in a particular build. If the source tree is small, or if developers are geographically dispersed, this is the preferred solution. In fact one approach for larger projects is to break a project down into smaller separately-compiled subsystems, and arrange a way of releasing them internally so that each developer need check out only those subsystems which they are actively working on.
Another approach is to set up a structure which allows
developers to have their own copies of some files, and
for other files to access source files from a central
location. Many people have come up with some such a
system using features such as the symbolic link feature
found in many operating systems, or the VPATH
feature found in many versions of make. One build
tool which is designed to help with this kind of thing
is Odin (see
ftp://ftp.cs.colorado.edu/pub/distribs/odin).
In normal circumstances, CVS works only with regular files. Every file in a project is assumed to be persistent; it must be possible to open, read and close them; and so on. CVS also ignores file permissions and ownerships, leaving such issues to be resolved by the developer at installation time. In other words, it is not possible to "check in" a device into a repository; if the device file cannot be opened, CVS will refuse to handle it. Files also lose their ownerships and permissions during repository transactions.
This appendix describes the overall structure of CVS commands, and describes some commands in detail (others are described elsewhere; for a quick reference to CVS commands, see Quick reference to CVS commands, and for an alphabetical list of all CVS commands, see Alphabetical list of all CVS commands).
The overall format of all CVS commands is:
cvs [ cvs_options ] cvs_command [ command_options ] [ command_args ]
cvsThe name of the CVS program.
cvs_optionsSome options that affect all sub-commands of CVS. These are described below.
cvs_commandOne of several different sub-commands. Some of the commands have aliases that can be used instead; those aliases are noted in the reference manual for that command. There are only two situations where you may omit ‘cvs_command’: ‘cvs -H’ elicits a list of available commands, and ‘cvs -v’ displays version information on CVS itself.
command_optionsOptions that are specific for the command.
command_argsArguments to the commands.
There is unfortunately some confusion between
cvs_options and command_options.
When given as a cvs_option, some options only
affect some of the commands. When given as a
command_option it may have a different meaning, and
be accepted by more commands. In other words, do not
take the above categorization too seriously. Look at
the documentation instead.
CVS can indicate to the calling environment whether it succeeded or failed by setting its exit status. The exact way of testing the exit status will vary from one operating system to another. For example in a unix shell script the ‘$?’ variable will be 0 if the last command returned a successful exit status, or greater than 0 if the exit status indicated failure.
If CVS is successful, it returns a successful status;
if there is an error, it prints an error message and
returns a failure status. The one exception to this is
the cvs diff command. It will return a
successful status if it found no differences, or a
failure status if there were differences or if there
was an error. Because this behavior provides no good
way to detect errors, in the future it is possible that
cvs diff will be changed to behave like the
other CVS commands.
There are some command_options that are used so
often that you might have set up an alias or some other
means to make sure you always specify that option. One
example (the one that drove the implementation of the
.cvsrc support, actually) is that many people find the
default output of the ‘diff’ command to be very
hard to read, and that either context diffs or unidiffs
are much easier to understand.
The ~/.cvsrc file is a way that you can add
default options to cvs_commands within cvs,
instead of relying on aliases or other shell scripts.
The format of the ~/.cvsrc file is simple. The
file is searched for a line that begins with the same
name as the cvs_command being executed. If a
match is found, then the remainder of the line is split
up (at whitespace characters) into separate options and
added to the command arguments before any
options from the command line.
If a command has two names (e.g., checkout and
co), the official name, not necessarily the one
used on the command line, will be used to match against
the file. So if this is the contents of the user’s
~/.cvsrc file:
log -N diff -uN rdiff -u update -Pd checkout -P release -d
the command ‘cvs checkout foo’ would have the ‘-P’ option added to the arguments, as well as ‘cvs co foo’.
With the example file above, the output from ‘cvs
diff foobar’ will be in unidiff format. ‘cvs diff
-c foobar’ will provide context diffs, as usual.
Getting "old" format diffs would be slightly more
complicated, because diff doesn’t have an option
to specify use of the "old" format, so you would need
‘cvs -f diff foobar’.
In place of the command name you can use cvs to
specify global options (see Global options). For
example the following line in .cvsrc
cvs -z6
causes CVS to use compression level 6.
The available ‘cvs_options’ (that are given to the left of ‘cvs_command’) are:
--allow-root=rootdirMay be invoked multiple times to specify one legal CVSROOT directory with each invocation. Also causes CVS to preparse the configuration file for each specified root, which can be useful when configuring write proxies, See Setting up the server for password authentication & Distributing load across several CVS servers.
-a ¶Authenticate all communication between the client and the server. Only has an effect on the CVS client. As of this writing, this is only implemented when using a GSSAPI connection (see Direct connection with GSSAPI). Authentication prevents certain sorts of attacks involving hijacking the active TCP connection. Enabling authentication does not enable encryption.
-b bindir ¶In CVS 1.9.18 and older, this specified that RCS programs are in the bindir directory. Current versions of CVS do not run RCS programs; for compatibility this option is accepted, but it does nothing.
-T tempdir ¶Use tempdir as the directory where temporary files are located.
The CVS client and server store temporary files in a temporary directory. The path to this temporary directory is set via, in order of precedence:
TmpDir in the config file (server only -
see The CVSROOT/config configuration file).
$TMPDIR environment variable (%TMPDIR% on
Windows - see All environment variables which affect CVS).
Temporary directories should always be specified as an absolute pathname. When running a CVS client, ‘-T’ affects only the local process; specifying ‘-T’ for the client has no effect on the server and vice versa.
-d cvs_root_directory ¶Use cvs_root_directory as the root directory
pathname of the repository. Overrides the setting of
the $CVSROOT environment variable. See The Repository.
-e editor ¶Use editor to enter revision log information. Overrides the
setting of the $CVSEDITOR and $EDITOR
environment variables. For more information, see
Committing your changes.
-fDo not read the ~/.cvsrc file. This option is most often used because of the non-orthogonality of the CVS option set. For example, the ‘cvs log’ option ‘-N’ (turn off display of tag names) does not have a corresponding option to turn the display on. So if you have ‘-N’ in the ~/.cvsrc entry for ‘log’, you may need to use ‘-f’ to show the tag names.
-gForges group-writable permissions on files in the working copy. This option is typically used when you have multiple users sharing a single checked out source tree, allowing them to operate their shells with a less dangerous umask at the expense of CVS security. To use this feature, create a directory to hold the checked-out source tree, set it to a private group, and set up the directory such that files created under it inherit the gid of the directory. On BSD systems, this occurs automatically. On SYSV systems and GNU/Linux, the sgid bit must be set on the directory for this. The users who are to share the checked out tree must be placed in that group which owns the directory.
Note that the sharing of a single checked-out source tree is very different from giving several users access to a common CVS repository. Access to a common CVS repository already maintains shared group-write permissions and does not require this option.
Due to the security implications, setting this option globally in your .cvsrc file is strongly discouraged; if you must, ensure all source checkouts are "firewalled" within a private group or a private mode 0700 directory.
This option is a MidnightBSD extension merged into Debian and MirBSD CVS.
-H--helpDisplay usage information about the specified ‘cvs_command’ (but do not actually execute the command). If you don’t specify a command name, ‘cvs -H’ displays overall help for CVS, including a list of other help options.
-R ¶Turns on read-only repository mode. This allows one to check out from a read-only repository, such as within an anoncvs server, or from a CD-ROM repository.
Same effect as if the CVSREADONLYFS environment
variable is set. Using ‘-R’ can also considerably
speed up checkouts over NFS.
-n ¶Do not change any files. Attempt to execute the ‘cvs_command’, but only to issue reports; do not remove, update, or merge any existing files, or create any new files.
Note that CVS will not necessarily produce exactly the same output as without ‘-n’. In some cases the output will be the same, but in other cases CVS will skip some of the processing that would have been required to produce the exact same output.
-QCause the command to be really quiet; the command will only generate output for serious problems.
-qCause the command to be somewhat quiet; informational messages, such as reports of recursion through subdirectories, are suppressed.
-r ¶Make new working files read-only. Same effect
as if the $CVSREAD environment variable is set
(see All environment variables which affect CVS). The default is to
make working files writable, unless watches are on
(see Mechanisms to track who is editing files).
-s variable=valueSet a user variable (see Expansions in administrative files).
-t ¶Trace program execution; display messages showing the steps of CVS activity. Particularly useful with ‘-n’ to explore the potential impact of an unfamiliar command.
-v--versionDisplay version and copyright information for CVS.
-w ¶Make new working files read-write. Overrides the
setting of the $CVSREAD environment variable.
Files are created read-write by default, unless $CVSREAD is
set or ‘-r’ is given.
-x ¶Encrypt all communication between the client and the server. Only has an effect on the CVS client. As of this writing, this is only implemented when using a GSSAPI connection (see Direct connection with GSSAPI) or a Kerberos connection (see Direct connection with Kerberos). Enabling encryption implies that message traffic is also authenticated. Encryption support is not available by default; it must be enabled using a special configure option, --enable-encryption, when you build CVS.
-z level ¶Request compression level for network traffic.
CVS interprets level identically to the gzip program.
Valid levels are 1 (high speed, low compression) to
9 (low speed, high compression), or 0 to disable
compression (the default). Data sent to the server will
be compressed at the requested level and the client will request
the server use the same compression level for data returned. The
server will use the closest level allowed by the server administrator to
compress returned data. This option only has an effect when passed to
the CVS client.
This section describes the ‘command_options’ that are available across several CVS commands. These options are always given to the right of ‘cvs_command’. Not all commands support all of these options; each option is only supported for commands where it makes sense. However, when a command has one of these options you can almost always count on the same behavior of the option as in other commands. (Other command options, which are listed with the individual commands, may have different behavior from one CVS command to the other).
Note: the ‘history’ command is an exception; it supports many options that conflict even with these standard options.
-D date_spec ¶Use the most recent revision no later than date_spec. date_spec is a single argument, a date description specifying a date in the past.
The specification is sticky when you use it to make a private copy of a source file; that is, when you get a working file using ‘-D’, CVS records the date you specified, so that further updates in the same directory will use the same date (for more information on sticky tags/dates, see Sticky tags).
‘-D’ is available with the annotate, checkout,
diff, export, history, ls,
rdiff, rls, rtag, tag, and update commands.
(The history command uses this option in a
slightly different way; see history options).
For a complete description of the date formats accepted by CVS, see Date input formats.
Remember to quote the argument to the ‘-D’ flag so that your shell doesn’t interpret spaces as argument separators. A command using the ‘-D’ flag can look like this:
$ cvs diff -D "1 hour ago" cvs.texinfo
-f ¶When you specify a particular date or tag to CVS commands, they normally ignore files that do not contain the tag (or did not exist prior to the date) that you specified. Use the ‘-f’ option if you want files retrieved even when there is no match for the tag or date. (The most recent revision of the file will be used).
Note that even with ‘-f’, a tag that you specify must exist (that is, in some file, not necessary in every file). This is so that CVS will continue to give an error if you mistype a tag name.
‘-f’ is available with these commands:
annotate, checkout, export,
rdiff, rtag, and update.
WARNING: The commit and remove
commands also have a
‘-f’ option, but it has a different behavior for
those commands. See commit options, and
Removing files.
-k kflagOverride the default processing of RCS keywords other than
‘-kb’. See Keyword substitution, for the meaning of
kflag. Used with the checkout and update
commands, your kflag specification is
sticky; that is, when you use this option
with a checkout or update command,
CVS associates your selected kflag with any files
it operates on, and continues to use that kflag with future
commands on the same files until you specify otherwise.
The ‘-k’ option is available with the add,
checkout, diff, export, import,
rdiff, and update commands.
WARNING: Prior to CVS version 1.12.2, the ‘-k’ flag overrode the ‘-kb’ indication for a binary file. This could sometimes corrupt binary files. See Merging and keywords, for more.
-lLocal; run only in current working directory, rather than recursing through subdirectories.
Available with the following commands: annotate, checkout,
commit, diff, edit, editors, export,
log, rdiff, remove, rtag,
status, tag, unedit, update, watch,
and watchers.
-m message ¶Use message as log information, instead of invoking an editor.
Available with the following commands: add,
commit and import.
-nDo not run any tag program. (A program can be specified to run in the modules database (see The modules file); this option bypasses it).
Note: this is not the same as the ‘cvs -n’ program option, which you can specify to the left of a cvs command!
Available with the checkout, commit, export,
and rtag commands.
-PPrune empty directories. See Removing directories.
-pPipe the files retrieved from the repository to standard output,
rather than writing them in the current directory. Available
with the checkout and update commands.
-RProcess directories recursively. This is the default for all CVS
commands, with the exception of ls & rls.
Available with the following commands: annotate, checkout,
commit, diff, edit, editors, export,
ls, rdiff, remove, rls, rtag,
status, tag, unedit, update, watch,
and watchers.
-r tag-r tag[:date] ¶Use the revision specified by the tag argument (and the date
argument for the commands which accept it) instead of the
default head revision. As well as arbitrary tags defined
with the tag or rtag command, two special tags are
always available: ‘HEAD’ refers to the most recent version
available in the repository (also known as the tip of the ‘MAIN’
branch, also known as trunk; the name of a branch refers to its tip;
this version of CVS introduces ‘.bhead’, but only for the
DIFF command, for the same), and ‘BASE’ refers to the
revision you last checked out into the current working directory.
The tag specification is sticky when you use this
with checkout or update to make your own
copy of a file: CVS remembers the tag and continues to use it on
future update commands, until you specify otherwise (for more information
on sticky tags/dates, see Sticky tags).
The tag can be either a symbolic or numeric tag, as described in Tags–Symbolic revisions, or the name of a branch, as described in Branching and merging. When tag is the name of a branch, some commands accept the optional date argument to specify the revision as of the given date on the branch. When a command expects a specific revision, the name of a branch is interpreted as the most recent revision on that branch.
As a Debian and MirBSD CVS extension, specifying ‘BASE’ as the date portion of the argument yields the base revision of the branch specified by the tag portion of the argument, i.e. the revision on the parent branch the tag branch split off, or, where both branches were the same. This option has not received very much testing, beware!
Specifying the ‘-q’ global option along with the ‘-r’ command option is often useful, to suppress the warning messages when the RCS file does not contain the specified tag.
Note: this is not the same as the overall ‘cvs -r’ option, which you can specify to the left of a CVS command!
‘-r tag’ is available with the commit and history
commands.
‘-r tag[:date]’ is available with the annotate,
checkout, diff, export, rdiff, rtag,
and update commands.
-WSpecify file names that should be filtered. You can
use this option repeatedly. The spec can be a file
name pattern of the same type that you can specify in
the .cvswrappers file.
Available with the following commands: import,
and update.
First, a quote:
Our units of temporal measurement, from seconds on up to months, are so complicated, asymmetrical and disjunctive so as to make coherent mental reckoning in time all but impossible. Indeed, had some tyrannical god contrived to enslave our minds to time, to make it all but impossible for us to escape subjection to sodden routines and unpleasant surprises, he could hardly have done better than handing down our present system. It is like a set of trapezoidal building blocks, with no vertical or horizontal surfaces, like a language in which the simplest thought demands ornate constructions, useless particles and lengthy circumlocutions. Unlike the more successful patterns of language and science, which enable us to face experience boldly or at least level-headedly, our system of temporal calculation silently and persistently encourages our terror of time.
… It is as though architects had to measure length in feet, width in meters and height in ells; as though basic instruction manuals demanded a knowledge of five different languages. It is no wonder then that we often look into our own immediate past or future, last Tuesday or a week from Sunday, with feelings of helpless confusion. …
— Robert Grudin, Time and the Art of Living.
This section describes the textual date representations that GNU
programs accept. These are the strings you, as a user, can supply as
arguments to the various programs. The C interface (via the
get_date function) is not described here.
get_dateA date is a string, possibly empty, containing many items separated by whitespace. The whitespace may be omitted when no ambiguity arises. The empty string means the beginning of today (i.e., midnight). Order of the items is immaterial. A date string may contain many flavors of items:
We describe each of these item types in turn, below.
A few ordinal numbers may be written out in words in some contexts. This is most useful for specifying day of the week items or relative items (see below). Among the most commonly used ordinal numbers, the word ‘last’ stands for -1, ‘this’ stands for 0, and ‘first’ and ‘next’ both stand for 1. Because the word ‘second’ stands for the unit of time there is no way to write the ordinal number 2, but for convenience ‘third’ stands for 3, ‘fourth’ for 4, ‘fifth’ for 5, ‘sixth’ for 6, ‘seventh’ for 7, ‘eighth’ for 8, ‘ninth’ for 9, ‘tenth’ for 10, ‘eleventh’ for 11 and ‘twelfth’ for 12.
When a month is written this way, it is still considered to be written numerically, instead of being “spelled in full”; this changes the allowed strings.
In the current implementation, only English is supported for words and abbreviations like ‘AM’, ‘DST’, ‘EST’, ‘first’, ‘January’, ‘Sunday’, ‘tomorrow’, and ‘year’.
The output of date is not always acceptable as a date string,
not only because of the language problem, but also because there is no
standard meaning for time zone items like ‘IST’. When using
date to generate a date string intended to be parsed later,
specify a date format that is independent of language and that does not
use time zone items other than ‘UTC’ and ‘Z’. Here are some
ways to do this:
$ LC_ALL=C TZ=UTC0 date Fri Dec 15 19:48:05 UTC 2000 $ TZ=UTC0 date +"%Y-%m-%d %H:%M:%SZ" 2000-12-15 19:48:05Z $ date --iso-8601=seconds # a GNU extension 2000-12-15T11:48:05-0800 $ date --iso-8601=ns # a GNU extension 2004-02-29T16:21:42,692722128-0800 $ date --iso-8601=ns | tr T ' ' # --iso-8601 is a GNU extension. 2004-02-29 16:21:42,692722128-0800 $ date --rfc-2822 # a GNU extension Fri, 15 Dec 2000 11:48:05 -0800 $ date +"%Y-%m-%d %H:%M:%S %z" # %z is a GNU extension. 2000-12-15 11:48:05 -0800 $ date +'@%s' # %s is a MirBSD extension. @1101064210 $ date +'@%s.%N' # %s and %N are GNU extensions. @1078100502.692722128
Alphabetic case is completely ignored in dates. Comments may be introduced between round parentheses, as long as included parentheses are properly nested. Hyphens not followed by a digit are currently ignored. Leading zeros on numbers are ignored.
A calendar date item specifies a day of the year. It is specified differently, depending on whether the month is specified numerically or literally. All these strings specify the same calendar date:
1972-09-24 # ISO 8601.
72-9-24 # Assume 19xx for 69 through 99,
# 20xx for 00 through 68.
72-09-24 # Leading zeros are ignored.
9/24/72 # Common U.S. writing.
24 September 1972
24 Sept 72 # September has a special abbreviation.
24 Sep 72 # Three-letter abbreviations always allowed.
Sep 24, 1972
24-sep-72
24sep72
The year can also be omitted. In this case, the last specified year is used, or the current year if none. For example:
9/24 sep 24
Here are the rules.
For numeric months, the ISO 8601 format ‘year-month-day’ is allowed, where year is any positive number, month is a number between 01 and 12, and day is a number between 01 and 31. A leading zero must be present if a number is less than ten. If year is 68 or smaller, then 2000 is added to it; otherwise, if year is less than 100, then 1900 is added to it. The construct ‘month/day/year’, popular in the United States, is accepted. Also ‘month/day’, omitting the year.
Literal months may be spelled out in full: ‘January’, ‘February’, ‘March’, ‘April’, ‘May’, ‘June’, ‘July’, ‘August’, ‘September’, ‘October’, ‘November’ or ‘December’. Literal months may be abbreviated to their first three letters, possibly followed by an abbreviating dot. It is also permitted to write ‘Sept’ instead of ‘September’.
When months are written literally, the calendar date may be given as any of the following:
day month year day month month day year day-month-year
Or, omitting the year:
month day
A time of day item in date strings specifies the time on a given day. Here are some examples, all of which represent the same time:
20:02:00.000000
20:02
8:02pm
20:02-0500 # In EST (U.S. Eastern Standard Time).
More generally, the time of day may be given as ‘hour:minute:second’, where hour is a number between 0 and 23, minute is a number between 0 and 59, and second is a number between 0 and 59, with an optional fraction separated by ‘.’ or ‘,’ consisting of digits. Alternatively, ‘:second’ can be omitted, in which case it is taken to be zero.
If the time is followed by ‘am’ or ‘pm’ (or ‘a.m.’ or ‘p.m.’), hour is restricted to run from 1 to 12, and ‘:minute’ may be omitted (taken to be zero). ‘am’ indicates the first half of the day, ‘pm’ indicates the second half of the day. In this notation, 12 is the predecessor of 1: midnight is ‘12am’ while noon is ‘12pm’. (This is the zero-oriented interpretation of ‘12am’ and ‘12pm’, as opposed to the old tradition derived from Latin which uses ‘12m’ for noon and ‘12pm’ for midnight.)
The time may alternatively be followed by a time zone correction, expressed as ‘shhmm’, where s is ‘+’ or ‘-’, hh is a number of zone hours and mm is a number of zone minutes. You can also separate hh from mm with a colon. When a time zone correction is given this way, it forces interpretation of the time relative to Coordinated Universal Time (UTC), overriding any previous specification for the time zone or the local time zone. For example, ‘+0530’ and ‘+05:30’ both stand for the time zone 5.5 hours ahead of UTC (e.g., India). The minute part of the time of day may not be elided when a time zone correction is used. This is the best way to specify a time zone correction by fractional parts of an hour.
Either ‘am’/‘pm’ or a time zone correction may be specified, but not both.
A time zone item specifies an international time zone, indicated by a small set of letters, e.g., ‘UTC’ or ‘Z’ for Coordinated Universal Time. Any included periods are ignored. By following a non-daylight-saving time zone by the string ‘DST’ in a separate word (that is, separated by some white space), the corresponding daylight saving time zone may be specified. Alternatively, a non-daylight-saving time zone can be followed by a time zone correction, to add the two values. This is normally done only for ‘UTC’; for example, ‘UTC+05:30’ is equivalent to ‘+05:30’.
Time zone items other than ‘UTC’ and ‘Z’ are obsolescent and are not recommended, because they are ambiguous; for example, ‘EST’ has a different meaning in Australia than in the United States. Instead, it’s better to use unambiguous numeric time zone corrections like ‘-0500’, as described in the previous section.
If neither a time zone item nor a time zone correction is supplied, time stamps are interpreted using the rules of the default time zone.
The explicit mention of a day of the week will forward the date (only if necessary) to reach that day of the week in the future.
Days of the week may be spelled out in full: ‘Sunday’, ‘Monday’, ‘Tuesday’, ‘Wednesday’, ‘Thursday’, ‘Friday’ or ‘Saturday’. Days may be abbreviated to their first three letters, optionally followed by a period. The special abbreviations ‘Tues’ for ‘Tuesday’, ‘Wednes’ for ‘Wednesday’ and ‘Thur’ or ‘Thurs’ for ‘Thursday’ are also allowed.
A number may precede a day of the week item to move forward supplementary weeks. It is best used in expression like ‘third monday’. In this context, ‘last day’ or ‘next day’ is also acceptable; they move one week before or after the day that day by itself would represent.
A comma following a day of the week item is ignored.
Relative items adjust a date (or the current date if none) forward or backward. The effects of relative items accumulate. Here are some examples:
1 year 1 year ago 3 years 2 days
The unit of time displacement may be selected by the string ‘year’ or ‘month’ for moving by whole years or months. These are fuzzy units, as years and months are not all of equal duration. More precise units are ‘fortnight’ which is worth 14 days, ‘week’ worth 7 days, ‘day’ worth 24 hours, ‘hour’ worth 60 minutes, ‘minute’ or ‘min’ worth 60 seconds, and ‘second’ or ‘sec’ worth one second. An ‘s’ suffix on these units is accepted and ignored.
The unit of time may be preceded by a multiplier, given as an optionally signed number. Unsigned numbers are taken as positively signed. No number at all implies 1 for a multiplier. Following a relative item by the string ‘ago’ is equivalent to preceding the unit by a multiplier with value -1.
The string ‘tomorrow’ is worth one day in the future (equivalent to ‘day’), the string ‘yesterday’ is worth one day in the past (equivalent to ‘day ago’).
The strings ‘now’ or ‘today’ are relative items corresponding to zero-valued time displacement, these strings come from the fact a zero-valued time displacement represents the current time when not otherwise changed by previous items. They may be used to stress other items, like in ‘12:00 today’. The string ‘this’ also has the meaning of a zero-valued time displacement, but is preferred in date strings like ‘this thursday’.
When a relative item causes the resulting date to cross a boundary where the clocks were adjusted, typically for daylight-saving time, the resulting date and time are adjusted accordingly.
The fuzz in units can cause problems with relative items. For example, ‘2003-07-31 -1 month’ might evaluate to 2003-07-01, because 2003-06-31 is an invalid date. To determine the previous month more reliably, you can ask for the month before the 15th of the current month. For example:
$ date -R Thu, 31 Jul 2003 13:02:39 -0700 $ date --date="-1 month" +'Last month was %B?' Last month was July? $ date --date="$(date +%Y-%m-15) -1 month" +'Last month was %B!' Last month was June!
Also, take care when manipulating dates around clock changes such as
daylight saving leaps. In a few cases these have added or subtracted
as much as 24 hours from the clock, so it is often wise to adopt
universal time by setting the TZ environment variable to
‘UTC0’ before embarking on calendrical calculations.
The precise interpretation of a pure decimal number depends on the context in the date string.
If the decimal number is of the form yyyymmdd and no other calendar date item (see Calendar date items) appears before it in the date string, then yyyy is read as the year, mm as the month number and dd as the day of the month, for the specified calendar date.
If the decimal number is of the form hhmm and no other time of day item appears before it in the date string, then hh is read as the hour of the day and mm as the minute of the hour, for the specified time of day. mm can also be omitted.
If both a calendar date and a time of day appear to the left of a number in the date string, but no relative item, then the number overrides the year.
If you give a string consisting of ‘@’ followed by a decimal number, it is parsed as an internal time stamp, UTC for POSIX compliant systems, TAI for systems which keep time correctly, and directly mapped to a kernel time. The implementation handles an optional fraction separated by ‘.’ or ‘,’ and truncates to a supported internal precision, rounding towards the negative infinity. Since the kernel time stamp represents complete date and time information, it cannot be combined with any other format given.
Although the date syntax here can represent any possible time since the
year zero, computer integers often cannot represent such a wide range of
time. On POSIX systems, the clock starts at 1970-01-01 00:00:00
UTC: POSIX does not require support for times before the
POSIX Epoch and times far in the future. GNU and
traditional Unix systems have 32-bit signed time_t and can represent
times from 1901-12-13 20:45:52 through 2038-01-19 03:14:07 UTC, such
that ‘@0’ represents the epoch, ‘@1’ represents 1970-01-01
00:00:01 UTC, and so forth, whereas ‘@-1’, not mandated by
POSIX, represents 1969-12-31 23:59:59 UTC. Systems with
64-bit signed time_t can represent all the times in the known
lifetime of the universe. Modern UNIX systems also can give
precise timecounters in the nanosecond or even attosecond range with
a resolution often only a small multiply, like 10000, of the CPU
frequency (on fast machines).
POSIX conformant systems do not count leap seconds, and their
kernel time is a seconds-since-epoch representation of UTC (which
is a calendar time); the MirOS family of operating systems keeps time
as seconds since the epoch, TAI, correctly counting leap seconds
and providing conversion functions. Most MirBSD ports have already
switched to a 64-bit signed time_t, some are using a
DJB-compatible tai_t internally. The rest of this
document has not been throughoutly checked for UTC vs TAI
correctness. For POSIXly broken systems, ‘@915148799’
represents 1998-12-31 23:59:59 UTC, ‘@915148800’ represents
1999-01-01 00:00:00 UTC, and there is no way to represent the
intervening leap second 1998-12-31 23:59:60 UTC. Also, calculation
of time deltas is wrong, such as the age of the MirBSD founder is already
off by more than 10 seconds in 2000.
get_date ¶get_date was originally implemented by Steven M. Bellovin
(smb@research.att.com) while at the University of North Carolina
at Chapel Hill. The code was later tweaked by a couple of people on
Usenet, then completely overhauled by Rich $alz (rsalz@bbn.com)
and Jim Berets (jberets@bbn.com) in August, 1990. Various
revisions for the GNU system were made by David MacKenzie, Jim Meyering,
Paul Eggert and others.
This chapter was originally produced by François Pinard (pinard@iro.umontreal.ca) from the getdate.y source code, and then edited by K. Berry (kb@cs.umb.edu).
The version of this chapter you are reading comes with MirBSD GNU
CVS 1.12 (also in Debian); it is based upon an older version of
the GNU coreutils manual which is not yet GFDL-licenced.
Appropriate changes for the in-tree get_date version of CVS
have been applied.
The MirBSD version is maintained by mirabilos m@mirbsd.org.
This is the CVS interface to assorted administrative facilities. Some of them have questionable usefulness for CVS but exist for historical purposes. Some of the questionable options are likely to disappear in the future. This command does work recursively, so extreme care should be used.
On unix, if there is a group named cvsadmin,
only members of that group can run cvs admin
commands, except for those specified using the
UserAdminOptions configuration option in the
CVSROOT/config file. Options specified using
UserAdminOptions can be run by any user. See
The CVSROOT/config configuration file for more on UserAdminOptions.
The cvsadmin group should exist on the server,
or any system running the non-client/server CVS.
To disallow cvs admin for all users, create a
group with no users in it. On NT, the cvsadmin
feature does not exist and all users
can run cvs admin.
Some of these options have questionable usefulness for CVS but exist for historical purposes. Some even make it impossible to use CVS until you undo the effect!
-AoldfileMight not work together with CVS. Append the access list of oldfile to the access list of the RCS file.
-aloginsMight not work together with CVS. Append the login names appearing in the comma-separated list logins to the access list of the RCS file.
-b[rev]Set the default branch to rev. In CVS, you
normally do not manipulate default branches; sticky
tags (see Sticky tags) are a better way to decide
which branch you want to work on. There is one reason
to run cvs admin -b: to revert to the vendor’s
version when using vendor branches (see Reverting to the latest vendor release).
There can be no space between ‘-b’ and its argument.
-cstring ¶Sets the comment leader to string. The comment leader is not used by current versions of CVS or RCS 5.7. Therefore, you can almost surely not worry about it. See Keyword substitution.
-e[logins]Might not work together with CVS. Erase the login names appearing in the comma-separated list logins from the access list of the RCS file. If logins is omitted, erase the entire access list. There can be no space between ‘-e’ and its argument.
-IRun interactively, even if the standard input is not a terminal. This option does not work with the client/server CVS and is likely to disappear in a future release of CVS.
-iUseless with CVS. This creates and initialises a
new RCS file, without depositing a revision. With
CVS, add files with the cvs add command
(see Adding files to a directory).
-ksubstSet the default keyword
substitution to subst. See Keyword substitution. Giving an explicit ‘-k’ option to
cvs update, cvs export, or cvs
checkout overrides this default.
-l[rev]Lock the revision with number rev. If a branch is given, lock the latest revision on that branch. If rev is omitted, lock the latest revision on the default branch. There can be no space between ‘-l’ and its argument.
This can be used in conjunction with the rcslock.pl script in the contrib directory of the CVS source distribution to provide reserved checkouts (where only one user can be editing a given file at a time). See the comments in that file for details (and see the README file in that directory for disclaimers about the unsupported nature of contrib). According to comments in that file, locking must set to strict (which is the default).
-LSet locking to strict. Strict locking means that the owner of an RCS file is not exempt from locking for checkin. For use with CVS, strict locking must be set; see the discussion under the ‘-l’ option above.
-mrev:msg ¶Replace the log message of revision rev with msg.
-Nname[:[rev]]Act like ‘-n’, except override any previous assignment of name. For use with magic branches, see Magic branch numbers.
-nname[:[rev]]Associate the symbolic name name with the branch or revision rev. It is normally better to use ‘cvs tag’ or ‘cvs rtag’ instead. Delete the symbolic name if both ‘:’ and rev are omitted; otherwise, print an error message if name is already associated with another number. If rev is symbolic, it is expanded before association. A rev consisting of a branch number followed by a ‘.’ stands for the current latest revision in the branch. A ‘:’ with an empty rev stands for the current latest revision on the default branch, normally the trunk. For example, ‘cvs admin -nname:’ associates name with the current latest revision of all the RCS files; this contrasts with ‘cvs admin -nname:$’ which associates name with the revision numbers extracted from keyword strings in the corresponding working files.
-orange ¶Deletes (outdates) the revisions given by range.
Note that this command can be quite dangerous unless you know exactly what you are doing (for example see the warnings below about how the rev1:rev2 syntax is confusing).
If you are short on disc this option might help you. But think twice before using it—there is no way short of restoring the latest backup to undo this command! If you delete different revisions than you planned, either due to carelessness or (heaven forbid) a CVS bug, there is no opportunity to correct the error before the revisions are deleted. It probably would be a good idea to experiment on a copy of the repository first.
Specify range in one of the following ways:
rev1::rev2Collapse all revisions between rev1 and rev2, so that CVS only stores the differences associated with going from rev1 to rev2, not intermediate steps. For example, after ‘-o 1.3::1.5’ one can retrieve revision 1.3, revision 1.5, or the differences to get from 1.3 to 1.5, but not the revision 1.4, or the differences between 1.3 and 1.4. Other examples: ‘-o 1.3::1.4’ and ‘-o 1.3::1.3’ have no effect, because there are no intermediate revisions to remove.
::revCollapse revisions between the beginning of the branch containing rev and rev itself. The branchpoint and rev are left intact. For example, ‘-o ::1.3.2.6’ deletes revision 1.3.2.1, revision 1.3.2.5, and everything in between, but leaves 1.3 and 1.3.2.6 intact.
rev::Collapse revisions between rev and the end of the branch containing rev. Revision rev is left intact but the head revision is deleted.
revDelete the revision rev. For example, ‘-o 1.3’ is equivalent to ‘-o 1.2::1.4’.
rev1:rev2Delete the revisions from rev1 to rev2, inclusive, on the same branch. One will not be able to retrieve rev1 or rev2 or any of the revisions in between. For example, the command ‘cvs admin -oR_1_01:R_1_02 .’ is rarely useful. It means to delete revisions up to, and including, the tag R_1_02. But beware! If there are files that have not changed between R_1_02 and R_1_03 the file will have the same numerical revision number assigned to the tags R_1_02 and R_1_03. So not only will it be impossible to retrieve R_1_02; R_1_03 will also have to be restored from the tapes! In most cases you want to specify rev1::rev2 instead.
:revDelete revisions from the beginning of the branch containing rev up to and including rev.
rev:Delete revisions from revision rev, including rev itself, to the end of the branch containing rev.
None of the revisions to be deleted may have branches or locks.
If any of the revisions to be deleted have symbolic
names, and one specifies one of the ‘::’ syntaxes,
then CVS will give an error and not delete any
revisions. If you really want to delete both the
symbolic names and the revisions, first delete the
symbolic names with cvs tag -d, then run
cvs admin -o. If one specifies the
non-‘::’ syntaxes, then CVS will delete the
revisions but leave the symbolic names pointing to
nonexistent revisions. This behavior is preserved for
compatibility with previous versions of CVS, but
because it isn’t very useful, in the future it may
change to be like the ‘::’ case.
Due to the way CVS handles branches rev cannot be specified symbolically if it is a branch. See Magic branch numbers, for an explanation.
Make sure that no-one has checked out a copy of the revision you outdate. Strange things will happen if he starts to edit it and tries to check it back in. For this reason, this option is not a good way to take back a bogus commit; commit a new revision undoing the bogus change instead (see Merging differences between any two revisions).
-qRun quietly; do not print diagnostics.
-sstate[:rev]Useful with CVS. Set the state attribute of the
revision rev to state. If rev is a
branch number, assume the latest revision on that
branch. If rev is omitted, assume the latest
revision on the default branch. Any identifier is
acceptable for state. A useful set of states is
‘Exp’ (for experimental), ‘Stab’ (for
stable), and ‘Rel’ (for released). By default,
the state of a new revision is set to ‘Exp’ when
it is created. The state is visible in the output from
cvs log (see log—Print out history information for files), and in the
‘$Log$’ and ‘$State$’ keywords
(see Keyword substitution). Note that CVS
uses the dead state for its own purposes (see The attic); to
take a file to or from the dead state use
commands like cvs remove and cvs add
(see Adding, removing, and renaming files and directories), not cvs admin -s.
-t[file]Useful with CVS. Write descriptive text from the contents of the named file into the RCS file, deleting the existing text. The file pathname may not begin with ‘-’. The descriptive text can be seen in the output from ‘cvs log’ (see log—Print out history information for files). There can be no space between ‘-t’ and its argument.
If file is omitted, obtain the text from standard input, terminated by end-of-file or by a line containing ‘.’ by itself. Prompt for the text if interaction is possible; see ‘-I’.
-t-stringSimilar to ‘-tfile’. Write descriptive text from the string into the RCS file, deleting the existing text. There can be no space between ‘-t’ and its argument.
-USet locking to non-strict. Non-strict locking means that the owner of a file need not lock a revision for checkin. For use with CVS, strict locking must be set; see the discussion under the ‘-l’ option above.
-u[rev]See the option ‘-l’ above, for a discussion of
using this option with CVS. Unlock the revision
with number rev. If a branch is given, unlock
the latest revision on that branch. If rev is
omitted, remove the latest lock held by the caller.
Normally, only the locker of a revision may unlock it;
somebody else unlocking a revision breaks the lock.
This causes the original locker to be sent a commit
notification (see Telling CVS to notify you).
There can be no space between ‘-u’ and its argument.
-VnIn previous versions of CVS, this option meant to write an RCS file which would be acceptable to RCS version n, but it is now obsolete and specifying it will produce an error.
-xsuffixesIn previous versions of CVS, this was documented as a way of specifying the names of the RCS files. However, CVS has always required that the RCS files used by CVS end in ‘,v’, so this option has never done anything useful.
rannotate [options] files…
For each file in files, print the head revision of the trunk, together with information on the last modification for each line. If backwards annotation is requested, show the first modification after the specified revision. (Backwards annotation currently appears to be broken.)
These standard options are supported by annotate
(see Common command options, for a complete description of
them):
-bBackwards, show when a line was removed. Currently appears to be broken.
-lLocal directory only, no recursion.
-RProcess directories recursively.
-fUse head revision if tag/date not found.
-FAnnotate binary files.
-r tag[:date]Annotate file as of specified revision/tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See Common command options.
-D dateAnnotate file as of specified date.
For example:
$ cvs annotate ssfile Annotations for ssfile *************** 1.1 (mary 27-Mar-96): ssfile line 1 1.2 (joe 28-Mar-96): ssfile line 2
The file ssfile currently contains two lines.
The ssfile line 1 line was checked in by
mary on March 27. Then, on March 28, joe
added a line ssfile line 2, without modifying
the ssfile line 1 line. This report doesn’t
tell you anything about lines which have been deleted
or replaced; you need to use cvs diff for that
(see diff—Show differences between revisions).
The options to cvs annotate are listed in
Quick reference to CVS commands, and can be used to select the files
and revisions to annotate. The options are described
in more detail there and in Common command options.
Create or update a working directory containing copies of the
source files specified by modules. You must execute
checkout before using most of the other CVS
commands, since most of them operate on your working
directory.
The modules are either symbolic names for some collection of source directories and files, or paths to directories or files in the repository. The symbolic names are defined in the ‘modules’ file. See The modules file.
Depending on the modules you specify, checkout may
recursively create directories and populate them with
the appropriate source files. You can then edit these
source files at any time (regardless of whether other
software developers are editing their own copies of the
sources); update them to include new changes applied by
others to the source repository; or commit your work as
a permanent change to the source repository.
Note that checkout is used to create
directories. The top-level directory created is always
added to the directory where checkout is
invoked, and usually has the same name as the specified
module. In the case of a module alias, the created
sub-directory may have a different name, but you can be
sure that it will be a sub-directory, and that
checkout will show the relative path leading to
each file as it is extracted into your private work
area (unless you specify the ‘-Q’ global option).
The files created by checkout are created
read-write, unless the ‘-r’ option to CVS
(see Global options) is specified, the
CVSREAD environment variable is specified
(see All environment variables which affect CVS), or a watch is in
effect for that file (see Mechanisms to track who is editing files).
Note that running checkout on a directory that was already
built by a prior checkout is also permitted.
This is similar to specifying the ‘-d’ option
to the update command in the sense that new
directories that have been created in the repository
will appear in your work area.
However, checkout takes a module name whereas
update takes a directory name. Also
to use checkout this way it must be run from the
top level directory (where you originally ran
checkout from), so before you run
checkout to update an existing directory, don’t
forget to change your directory to the top level
directory.
For the output produced by the checkout command
see update output.
These standard options are supported by checkout
(see Common command options, for a complete description of
them):
-D dateUse the most recent revision no later than date. This option is sticky, and implies ‘-P’. See Sticky tags, for more information on sticky tags/dates.
-fOnly useful with the ‘-D’ or ‘-r’ flags. If no matching revision is found, retrieve the most recent revision (instead of ignoring the file).
-k kflagProcess keywords according to kflag. See
Keyword substitution.
This option is sticky; future updates of
this file in this working directory will use the same
kflag. The status command can be viewed
to see the sticky options. See Quick reference to CVS commands, for
more information on the status command.
-lLocal; run only in current working directory.
-nDo not run any checkout program (as specified with the ‘-o’ option in the modules file; see The modules file).
-PPrune empty directories. See Moving and renaming directories.
-pPipe files to the standard output.
-RCheckout directories recursively. This option is on by default.
-r tag[:date]Checkout the revision specified by tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. This option is sticky, and implies ‘-P’. See Sticky tags, for more information on sticky tags/dates. Also, see Common command options.
In addition to those, you can use these special command
options with checkout:
-AReset any sticky tags, dates, or ‘-k’ options. See Sticky tags, for more information on sticky tags/dates.
-cCopy the module file, sorted, to the standard output, instead of creating or modifying any files or directories in your working directory.
-d dirCreate a directory called dir for the working files, instead of using the module name. In general, using this flag is equivalent to using ‘mkdir dir; cd dir’ followed by the checkout command without the ‘-d’ flag.
There is an important exception, however. It is very convenient when checking out a single item to have the output appear in a directory that doesn’t contain empty intermediate directories. In this case only, CVS tries to “shorten” pathnames to avoid those empty directories.
For example, given a module ‘foo’ that contains the file ‘bar.c’, the command ‘cvs co -d dir foo’ will create directory ‘dir’ and place ‘bar.c’ inside. Similarly, given a module ‘bar’ which has subdirectory ‘baz’ wherein there is a file ‘quux.c’, the command ‘cvs co -d dir bar/baz’ will create directory ‘dir’ and place ‘quux.c’ inside.
Using the ‘-N’ flag will defeat this behavior. Given the same module definitions above, ‘cvs co -N -d dir foo’ will create directories ‘dir/foo’ and place ‘bar.c’ inside, while ‘cvs co -N -d dir bar/baz’ will create directories ‘dir/bar/baz’ and place ‘quux.c’ inside.
-j tagWith two ‘-j’ options, merge changes from the revision specified with the first ‘-j’ option to the revision specified with the second ‘j’ option, into the working directory.
With one ‘-j’ option, merge changes from the ancestor revision to the revision specified with the ‘-j’ option, into the working directory. The ancestor revision is the common ancestor of the revision which the working directory is based on, and the revision specified in the ‘-j’ option.
In addition, each -j option can contain an optional date specification which, when used with branches, can limit the chosen revision to one within a specific date. An optional date is specified by adding a colon (:) to the tag: ‘-jSymbolic_Tag:Date_Specifier’.
-NOnly useful together with ‘-d dir’. With this option, CVS will not “shorten” module paths in your working directory when you check out a single module. See the ‘-d’ flag for examples and a discussion.
-sLike ‘-c’, but include the status of all modules, and sort it by the status string. See The modules file, for info about the ‘-s’ option that is used inside the modules file to set the module status.
Get a copy of the module ‘tc’:
$ cvs checkout tc
Get a copy of the module ‘tc’ as it looked one day ago:
$ cvs checkout -D yesterday tc
Use commit when you want to incorporate changes
from your working source files into the source
repository.
If you don’t specify particular files to commit, all of
the files in your working current directory are
examined. commit is careful to change in the
repository only those files that you have really
changed. By default (or if you explicitly specify the
‘-R’ option), files in subdirectories are also
examined and committed if they have changed; you can
use the ‘-l’ option to limit commit to the
current directory only.
commit verifies that the selected files are up
to date with the current revisions in the source
repository; it will notify you, and exit without
committing, if any of the specified files must be made
current first with update (see update—Bring work tree in sync with repository).
commit does not call the update command
for you, but rather leaves that for you to do when the
time is right.
When all is well, an editor is invoked to allow you to
enter a log message that will be written to one or more
logging programs (see The modules file, and see Loginfo)
and placed in the RCS file inside the
repository. This log message can be retrieved with the
log command; see log—Print out history information for files. You can specify the
log message on the command line with the ‘-m
message’ option, and thus avoid the editor invocation,
or use the ‘-F file’ option to specify
that the argument file contains the log message.
At commit, a unique commitid is placed in the RCS
file inside the repository. All files committed at once
get the same commitid, a string consisting only of hexadecimal
digits (usually 16 in GNU CVS, 19 in Debian and MirBSD CVS).
FSF GNU CVS 1.11 and OpenBSD OpenCVS do not support commitids yet.
The commitid can be retrieved with
the log and status command; see log—Print out history information for files and
File status.
These standard options are supported by commit
(see Common command options, for a complete description of
them):
-lLocal; run only in current working directory.
-RCommit directories recursively. This is on by default.
-r revisionCommit to revision. revision must be either a branch, or a revision on the main trunk that is higher than any existing revision number (see Assigning revisions). You cannot commit to a specific revision on a branch.
commit also supports these options:
-cRefuse to commit files unless the user has registered a valid edit on the
file via cvs edit. This is most useful when ‘commit -c’
and ‘edit -c’ have been placed in all .cvsrc files.
A commit can be forced anyways by either regestering an edit retroactively
via cvs edit (no changes to the file will be lost) or using the
-f option to commit. Support for commit -c requires both
client and a server versions 1.12.10 or greater.
-F fileRead the log message from file, instead of invoking an editor.
-fNote that this is not the standard behavior of the ‘-f’ option as defined in Common command options.
Force CVS to commit a new revision even if you haven’t
made any changes to the file. As of CVS version 1.12.10,
it also causes the -c option to be ignored. If the current revision
of file is 1.7, then the following two commands
are equivalent:
$ cvs commit -f file $ cvs commit -r 1.8 file
The ‘-f’ option disables recursion (i.e., it implies ‘-l’). To force CVS to commit a new revision for all files in all subdirectories, you must use ‘-f -R’.
-m messageUse message as the log message, instead of invoking an editor.
You can commit to a branch revision (one that has an
even number of dots) with the ‘-r’ option. To
create a branch revision, use the ‘-b’ option
of the rtag or tag commands
(see Branching and merging). Then, either checkout or
update can be used to base your sources on the
newly created branch. From that point on, all
commit changes made within these working sources
will be automatically added to a branch revision,
thereby not disturbing main-line development in any
way. For example, if you had to create a patch to the
1.2 version of the product, even though the 2.0 version
is already under development, you might do:
$ cvs rtag -b -r FCS1_2 FCS1_2_Patch product_module $ cvs checkout -r FCS1_2_Patch product_module $ cd product_module [[ hack away ]] $ cvs commit
This works automatically since the ‘-r’ option is sticky.
Say you have been working on some extremely experimental software, based on whatever revision you happened to checkout last week. If others in your group would like to work on this software with you, but without disturbing main-line development, you could commit your change to a new branch. Others can then checkout your experimental stuff and utilise the full benefit of CVS conflict resolution. The scenario might look like:
[[ hacked sources are present ]] $ cvs tag -b EXPR1 $ cvs update -r EXPR1 $ cvs commit
The update command will make the ‘-r
EXPR1’ option sticky on all files. Note that your
changes to the files will never be removed by the
update command. The commit will
automatically commit to the correct branch, because the
‘-r’ is sticky. You could also do like this:
[[ hacked sources are present ]] $ cvs tag -b EXPR1 $ cvs commit -r EXPR1
but then, only those files that were changed by you will have the ‘-r EXPR1’ sticky flag. If you hack away, and commit without specifying the ‘-r EXPR1’ flag, some files may accidentally end up on the main trunk.
To work with you on the experimental change, others would simply do
$ cvs checkout -r EXPR1 whatever_module
The diff command is used to compare different
revisions of files. The default action is to compare
your working files with the revisions they were based
on, and report any differences that are found.
If any file names are given, only those files are compared. If any directories are given, all files under them will be compared.
The exit status for diff is different than for other CVS commands; for details see CVS’s exit status.
These standard options are supported by diff
(see Common command options, for a complete description of
them):
-D dateUse the most recent revision no later than date. See ‘-r’ for how this affects the comparison.
-k kflagProcess keywords according to kflag. See Keyword substitution.
-lLocal; run only in current working directory.
-RExamine directories recursively. This option is on by default.
-r tag[:date]Compare with revision specified by tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. Zero, one or two ‘-r’ options can be present. With no ‘-r’ option, the working file will be compared with the revision it was based on. With one ‘-r’, that revision will be compared to your current working file. With two ‘-r’ options those two revisions will be compared (and your working file will not affect the outcome in any way).
One or both ‘-r’ options can be replaced by a ‘-D date’ option, described above.
The following options specify the format of the output. They have the same meaning as in GNU diff. Most options have two equivalent names, one of which is a single letter preceded by ‘-’, and the other of which is a long name preceded by ‘--’.
Show lines (an integer) lines of context. This option does not
specify an output format by itself; it has no effect unless it is
combined with ‘-c’ or ‘-u’. This option is obsolete. For proper
operation, patch typically needs at least two lines of context.
Treat all files as text and compare them line-by-line, even if they do not seem to be text.
Ignore trailing white space and consider all other sequences of one or more white space characters to be equivalent.
Ignore changes that just insert or delete blank lines.
Read and write data in binary mode.
Report only whether the files differ, not the details of the differences.
Use the context output format.
Use the context output format, showing lines (an integer) lines of
context, or three if lines is not given.
For proper operation, patch typically needs at least two lines of
context.
Use format to output a line group containing differing lines from both files in if-then-else format. See Line group formats.
Change the algorithm to perhaps find a smaller set of changes. This makes
diff slower (sometimes much slower).
Make output that is a valid ed script.
Expand tabs to spaces in the output, to preserve the alignment of tabs in the input files.
Make output that looks vaguely like an ed script but has changes
in the order they appear in the file.
In context and unified format, for each hunk of differences, show some of the last preceding line that matches regexp.
Make output that looks vaguely like an ed script but has changes
in the order they appear in the file.
Use heuristics to speed handling of large files that have numerous scattered small changes.
Do not discard the last lines lines of the common prefix and the first lines lines of the common suffix.
Ignore changes in case; consider upper- and lower-case letters equivalent.
Ignore changes that just insert or delete lines that match regexp.
Make merged if-then-else output using name.
Ignore white space when comparing lines.
Ignore changes that just insert or delete blank lines.
Ignore changes in case; consider upper- and lower-case to be the same.
Ignore changes that just insert or delete lines that match regexp.
Ignore trailing white space and consider all other sequences of one or more white space characters to be equivalent.
Output a tab rather than a space before the text of a line in normal or context format. This causes the alignment of tabs in the line to look normal.
Use label instead of the file name in the context format and unified format headers.
Use label instead of the file name in the context format and unified format headers.
Print only the left column of two common lines in side by side format.
Use format to output all input lines in if-then-else format. See Line formats.
Change the algorithm to perhaps find a smaller set of changes. This
makes diff slower (sometimes much slower).
Output RCS-format diffs; like ‘-f’ except that each command specifies the number of lines affected.
In directory comparison, if a file is found in only one directory, treat it as present but empty in the other directory.
Use format to output a group of lines taken from just the second file in if-then-else format. See Line group formats.
Use format to output a line taken from just the second file in if-then-else format. See Line formats.
Use format to output a group of lines taken from just the first file in if-then-else format. See Line group formats.
Use format to output a line taken from just the first file in if-then-else format. See Line formats.
Show which C function each change is in.
Output RCS-format diffs; like ‘-f’ except that each command specifies the number of lines affected.
Report when two files are the same.
Show which C function each change is in.
In context and unified format, for each hunk of differences, show some of the last preceding line that matches regexp.
Use the side by side output format.
Use heuristics to speed handling of large files that have numerous scattered small changes.
Do not print common lines in side by side format.
Expand tabs to spaces in the output, to preserve the alignment of tabs in the input files.
Output a tab rather than a space before the text of a line in normal or context format. This causes the alignment of tabs in the line to look normal.
Treat all files as text and compare them line-by-line, even if they do not appear to be text.
Use the unified output format.
Use format to output a group of common lines taken from both files in if-then-else format. See Line group formats.
Use format to output a line common to both files in if-then-else format. See Line formats.
Use the unified output format, showing lines (an integer) lines of
context, or three if lines is not given.
For proper operation, patch typically needs at least two lines of
context.
Ignore white space when comparing lines.
Use an output width of columns in side by side format.
Use the side by side output format.
Line group formats let you specify formats suitable for many applications that allow if-then-else input, including programming languages and text formatting languages. A line group format specifies the output format for a contiguous group of similar lines.
For example, the following command compares the TeX file myfile with the original version from the repository, and outputs a merged file in which old regions are surrounded by ‘\begin{em}’-‘\end{em}’ lines, and new regions are surrounded by ‘\begin{bf}’-‘\end{bf}’ lines.
cvs diff \
--old-group-format='\begin{em}
%<\end{em}
' \
--new-group-format='\begin{bf}
%>\end{bf}
' \
myfile
The following command is equivalent to the above example, but it is a little more verbose, because it spells out the default line group formats.
cvs diff \
--old-group-format='\begin{em}
%<\end{em}
' \
--new-group-format='\begin{bf}
%>\end{bf}
' \
--unchanged-group-format='%=' \
--changed-group-format='\begin{em}
%<\end{em}
\begin{bf}
%>\end{bf}
' \
myfile
Here is a more advanced example, which outputs a diff listing with headers containing line numbers in a “plain English” style.
cvs diff \ --unchanged-group-format='' \ --old-group-format='-------- %dn line%(n=1?:s) deleted at %df: %<' \ --new-group-format='-------- %dN line%(N=1?:s) added after %de: %>' \ --changed-group-format='-------- %dn line%(n=1?:s) changed at %df: %<-------- to: %>' \ myfile
To specify a line group format, use one of the options listed below. You can specify up to four line group formats, one for each kind of line group. You should quote format, because it typically contains shell metacharacters.
These line groups are hunks containing only lines from the first file. The default old group format is the same as the changed group format if it is specified; otherwise it is a format that outputs the line group as-is.
These line groups are hunks containing only lines from the second file. The default new group format is same as the changed group format if it is specified; otherwise it is a format that outputs the line group as-is.
These line groups are hunks containing lines from both files. The default changed group format is the concatenation of the old and new group formats.
These line groups contain lines common to both files. The default unchanged group format is a format that outputs the line group as-is.
In a line group format, ordinary characters represent themselves; conversion specifications start with ‘%’ and have one of the following forms.
stands for the lines from the first file, including the trailing newline. Each line is formatted according to the old line format (see Line formats).
stands for the lines from the second file, including the trailing newline. Each line is formatted according to the new line format.
stands for the lines common to both files, including the trailing newline. Each line is formatted according to the unchanged line format.
stands for ‘%’.
where C is a single character, stands for C. C may not be a backslash or an apostrophe. For example, ‘%c':'’ stands for a colon, even inside the then-part of an if-then-else format, which a colon would normally terminate.
where O is a string of 1, 2, or 3 octal digits, stands for the character with octal code O. For example, ‘%c'\0'’ stands for a null character.
where F is a printf conversion specification and n is one
of the following letters, stands for n’s value formatted with F.
The line number of the line just before the group in the old file.
The line number of the first line in the group in the old file; equals e + 1.
The line number of the last line in the group in the old file.
The line number of the line just after the group in the old file; equals l + 1.
The number of lines in the group in the old file; equals l - f + 1.
Likewise, for lines in the new file.
The printf conversion specification can be ‘%d’,
‘%o’, ‘%x’, or ‘%X’, specifying decimal, octal,
lower case hexadecimal, or upper case hexadecimal output
respectively. After the ‘%’ the following options can appear in
sequence: a ‘-’ specifying left-justification; an integer
specifying the minimum field width; and a period followed by an
optional integer specifying the minimum number of digits.
For example, ‘%5dN’ prints the number of new lines in the group
in a field of width 5 characters, using the printf format "%5d".
If A equals B then T else E. A and B are each either a decimal constant or a single letter interpreted as above. This format spec is equivalent to T if A’s value equals B’s; otherwise it is equivalent to E.
For example, ‘%(N=0?no:%dN) line%(N=1?:s)’ is equivalent to ‘no lines’ if N (the number of lines in the group in the new file) is 0, to ‘1 line’ if N is 1, and to ‘%dN lines’ otherwise.
Line formats control how each line taken from an input file is output as part of a line group in if-then-else format.
For example, the following command outputs text with a one-column change indicator to the left of the text. The first column of output is ‘-’ for deleted lines, ‘|’ for added lines, and a space for unchanged lines. The formats contain newline characters where newlines are desired on output.
cvs diff \ --old-line-format='-%l ' \ --new-line-format='|%l ' \ --unchanged-line-format=' %l ' \ myfile
To specify a line format, use one of the following options. You should quote format, since it often contains shell metacharacters.
formats lines just from the first file.
formats lines just from the second file.
formats lines common to both files.
formats all lines; in effect, it sets all three above options simultaneously.
In a line format, ordinary characters represent themselves; conversion specifications start with ‘%’ and have one of the following forms.
stands for the contents of the line, not counting its trailing newline (if any). This format ignores whether the line is incomplete.
stands for the contents of the line, including its trailing newline (if any). If a line is incomplete, this format preserves its incompleteness.
stands for ‘%’.
where C is a single character, stands for C. C may not be a backslash or an apostrophe. For example, ‘%c':'’ stands for a colon.
where O is a string of 1, 2, or 3 octal digits, stands for the character with octal code O. For example, ‘%c'\0'’ stands for a null character.
where F is a printf conversion specification,
stands for the line number formatted with F.
For example, ‘%.5dn’ prints the line number using the
printf format "%.5d". See Line group formats, for
more about printf conversion specifications.
The default line format is ‘%l’ followed by a newline character.
If the input contains tab characters and it is important that they line up on output, you should ensure that ‘%l’ or ‘%L’ in a line format is just after a tab stop (e.g. by preceding ‘%l’ or ‘%L’ with a tab character), or you should use the ‘-t’ or ‘--expand-tabs’ option.
Taken together, the line and line group formats let you specify many
different formats. For example, the following command uses a format
similar to diff’s normal format. You can tailor this command
to get fine control over diff’s output.
cvs diff \ --old-line-format='< %l ' \ --new-line-format='> %l ' \ --old-group-format='%df%(f=l?:,%dl)d%dE %<' \ --new-group-format='%dea%dF%(F=L?:,%dL) %>' \ --changed-group-format='%df%(f=l?:,%dl)c%dF%(F=L?:,%dL) %<--- %>' \ --unchanged-group-format='' \ myfile
The following line produces a Unidiff (‘-u’ flag) between revision 1.14 and 1.19 of backend.c. Due to the ‘-kk’ flag no keywords are substituted, so differences that only depend on keyword substitution are ignored.
$ cvs diff -kk -u -r 1.14 -r 1.19 backend.c
Suppose the experimental branch EXPR1 was based on a set of files tagged RELEASE_1_0. To see what has happened on that branch, the following can be used:
$ cvs diff -r RELEASE_1_0 -r EXPR1
A command like this can be used to produce a context diff between two releases:
$ cvs diff -c -r RELEASE_1_0 -r RELEASE_1_1 > diffs
If you are maintaining ChangeLogs, a command like the following just before you commit your changes may help you write the ChangeLog entry. All local modifications that have not yet been committed will be printed.
$ cvs diff -u | less
This command is a variant of checkout; use it
when you want a copy of the source for module without
the CVS administrative directories. For example, you
might use export to prepare source for shipment
off-site. This command requires that you specify a
date or tag (with ‘-D’ or ‘-r’), so that you
can count on reproducing the source you ship to others
(and thus it always prunes empty directories).
One often would like to use ‘-kv’ with cvs
export. This causes any keywords to be
expanded such that an import done at some other site
will not lose the keyword revision information. But be
aware that doesn’t handle an export containing binary
files correctly. Also be aware that after having used
‘-kv’, one can no longer use the ident
command (which is part of the RCS suite—see
ident(1)) which looks for keyword strings. If
you want to be able to use ident you must not
use ‘-kv’.
These standard options are supported by export
(see Common command options, for a complete description of
them):
-D dateUse the most recent revision no later than date.
-fIf no matching revision is found, retrieve the most recent revision (instead of ignoring the file).
-lLocal; run only in current working directory.
-nDo not run any checkout program.
-RExport directories recursively. This is on by default.
-r tag[:date]Export the revision specified by tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See Common command options.
In addition, these options (that are common to
checkout and export) are also supported:
-d dirCreate a directory called dir for the working files, instead of using the module name. See checkout options, for complete details on how CVS handles this flag.
-k substSet keyword expansion mode (see Substitution modes).
-NOnly useful together with ‘-d dir’. See checkout options, for complete details on how CVS handles this flag.
CVS can keep a history log that tracks each use of most CVS
commands. You can use history to display this information in
various formats.
To enable logging, the ‘LogHistory’ config option must be set to some value other than the empty string and the history file specified by the ‘HistoryLogPath’ option must be writable by all users who may run the CVS executable (see The CVSROOT/config configuration file).
To enable the history command, logging must be enabled as above and
the ‘HistorySearchPath’ config option (see The CVSROOT/config configuration file) must be set to
specify some number of the history logs created thereby and these files must
be readable by each user who might run the history command.
Creating a repository via the cvs init command will enable logging of
all possible events to a single history log file
($CVSROOT/CVSROOT/history) with read and write permissions for all
users (see Creating a repository).
Note: history uses ‘-f’, ‘-l’,
‘-n’, and ‘-p’ in ways that conflict with the
normal use inside CVS (see Common command options).
Several options (shown above as ‘-report’) control what kind of report is generated:
-cReport on each time commit was used (i.e., each time the repository was modified).
-eEverything (all record types). Equivalent to specifying ‘-x’ with all record types. Of course, ‘-e’ will also include record types which are added in a future version of CVS; if you are writing a script which can only handle certain record types, you’ll want to specify ‘-x’.
-m moduleReport on a particular module. (You can meaningfully use ‘-m’ more than once on the command line.)
-oReport on checked-out modules. This is the default report type.
-TReport on all tags.
-x typeExtract a particular set of record types type from the CVS history. The types are indicated by single letters, which you may specify in combination.
Certain commands have a single record type:
Frelease
Ocheckout
Eexport
Trtag
One of five record types may result from an update:
CA merge was necessary but collisions were detected (requiring manual merging).
GA merge was necessary and it succeeded.
UA working file was copied from the repository.
PA working file was patched to match the repository.
WThe working copy of a file was deleted during update (because it was gone from the repository).
One of three record types results from commit:
AA file was added for the first time.
MA file was modified.
RA file was removed.
The options shown as ‘-flags’ constrain or expand the report without requiring option arguments:
-aShow data for all users (the default is to show data
only for the user executing history).
-lShow last modification only.
-wShow only the records for modifications done from the
same working directory where history is
executing.
The options shown as ‘-options args’ constrain the report based on an argument:
-b strShow data back to a record containing the string str in either the module name, the file name, or the repository path.
-D dateShow data since date. This is slightly different from the normal use of ‘-D date’, which selects the newest revision older than date.
-f fileShow data for a particular file (you can specify several ‘-f’ options on the same command line). This is equivalent to specifying the file on the command line.
-n moduleShow data for a particular module (you can specify several ‘-n’ options on the same command line).
-p repositoryShow data for a particular source repository (you can specify several ‘-p’ options on the same command line).
-r revShow records referring to revisions since the revision or tag named rev appears in individual RCS files. Each RCS file is searched for the revision or tag.
-t tagShow records since tag tag was last added to the history file. This differs from the ‘-r’ flag above in that it reads only the history file, not the RCS files, and is much faster.
-u nameShow records for user name.
-z timezoneShow times in the selected records using the specified time zone instead of UTC.
Use import to incorporate an entire source
distribution from an outside source (e.g., a source
vendor) into your source repository directory. You can
use this command both for initial creation of a
repository, and for wholesale updates to the module
from the outside source. See Tracking third-party sources, for
a discussion on this subject.
The repository argument gives a directory name (or a path to a directory) under the CVS root directory for repositories; if the directory did not exist, import creates it.
When you use import for updates to source that has been modified in your source repository (since a prior import), it will notify you of any files that conflict in the two branches of development; use ‘checkout -j’ to reconcile the differences, as import instructs you to do.
If CVS decides a file should be ignored (see Ignoring files via cvsignore), it does not import it and prints ‘I ’ followed by the filename (see import output, for a complete description of the output).
If the file $CVSROOT/CVSROOT/cvswrappers exists, any file whose names match the specifications in that file will be treated as packages and the appropriate filtering will be performed on the file/directory before being imported. See The cvswrappers file.
The outside source is saved in a first-level branch, by default 1.1.1. Updates are leaves of this branch; for example, files from the first imported collection of source will be revision 1.1.1.1, then files from the first imported update will be revision 1.1.1.2, and so on.
At least three arguments are required.
repository is needed to identify the collection
of source. vendortag is a tag for the entire
branch (e.g., for 1.1.1). You must also specify at
least one releasetag to uniquely identify the files at
the leaves created each time you execute import. The
releasetag should be new, not previously existing in the
repository file, and uniquely identify the imported release,
Note that import does not change the
directory in which you invoke it. In particular, it
does not set up that directory as a CVS working
directory; if you want to work with the sources import
them first and then check them out into a different
directory (see Getting the source).
This standard option is supported by import
(see Common command options, for a complete description):
-m messageUse message as log information, instead of invoking an editor.
There are the following additional special options.
-b branch-k substIndicate the keyword expansion mode desired. This setting will apply to all files created during the import, but not to any files that previously existed in the repository. See Substitution modes, for a list of valid ‘-k’ settings.
-I nameSpecify file names that should be ignored during import. You can use this option repeatedly. To avoid ignoring any files at all (even those ignored by default), specify ‘-I !’.
name can be a file name pattern of the same type that you can specify in the .cvsignore file. See Ignoring files via cvsignore.
-W specSpecify file names that should be filtered during import. You can use this option repeatedly.
spec can be a file name pattern of the same type that you can specify in the .cvswrappers file. See The cvswrappers file.
-XModify the algorithm used by CVS when importing new files so that new files do not immediately appear on the main trunk.
Specifically, this flag causes CVS to mark new files as
if they were deleted on the main trunk, by taking the following
steps for each file in addition to those normally taken on import:
creating a new revision on the main trunk indicating that
the new file is dead, resetting the new file’s default branch,
and placing the file in the Attic (see The attic) directory.
Setting the ‘ImportNewFilesToVendorBranchOnly’ option in CVSROOT/config (see The CVSROOT/config configuration file) forces use of this option on a repository-wide basis.
import keeps you informed of its progress by printing a line
for each file, preceded by one character indicating the status of the file:
U fileThe file already exists in the repository and has not been locally modified; a new revision has been created (if necessary).
N fileThe file is a new file which has been added to the repository.
C fileThe file already exists in the repository but has been locally modified; you will have to merge the changes.
I fileThe file is being ignored (see Ignoring files via cvsignore).
L fileThe file is a symbolic link; cvs import ignores symbolic links.
People periodically suggest that this behavior should
be changed, but if there is a consensus on what it
should be changed to, it is not apparent.
(Various options in the modules file can be used
to recreate symbolic links on checkout, update, etc.;
see The modules file.)
See Tracking third-party sources, and Creating a directory tree from a number of files.
rlog [options] [files…]
Display log information for files. log used to
call the RCS utility rlog. Although this
is no longer true in the current sources, this history
determines the format of the output and the options,
which are not quite in the style of the other CVS
commands.
The output includes the location of the RCS file,
the head revision (the latest revision on the
trunk), all symbolic names (tags) and some other
things. For each revision, the revision number, the
date, the author, the number of lines added/deleted, the commitid
and the log message are printed. All dates are displayed
in local time at the client. This is typically specified in
the $TZ environment variable, which can be set to
govern how log displays dates.
Note: log uses ‘-R’ in a way that conflicts
with the normal use inside CVS (see Common command options).
By default, log prints all information that is
available. All other options restrict the output. Note that the revision
selection options (-d, -r, -s, and -w) have no
effect, other than possibly causing a search for files in Attic directories,
when used in conjunction with the options that restrict the output to only
log header fields (-b, -h, -R, and -t)
unless the -S option is also specified.
-bPrint information about the revisions on the default branch, normally the highest branch on the trunk.
-d datesPrint information about revisions with a checkin date/time in the range given by the semicolon-separated list of dates. The date formats accepted are those accepted by the ‘-D’ option to many other CVS commands (see Common command options). Dates can be combined into ranges as follows:
d1<d2d2>d1Select the revisions that were deposited between d1 and d2.
<dd>Select all revisions dated d or earlier.
d<>dSelect all revisions dated d or later.
dSelect the single, latest revision dated d or earlier.
The ‘>’ or ‘<’ characters may be followed by ‘=’ to indicate an inclusive range rather than an exclusive one.
Note that the separator is a semicolon (;).
-hPrint only the name of the RCS file, name of the file in the working directory, head, default branch, access list, locks, symbolic names, and suffix.
-lLocal; run only in current working directory. (Default is to run recursively).
-NDo not print the list of tags for this file. This option can be very useful when your site uses a lot of tags, so rather than "more"’ing over 3 pages of tag information, the log information is presented without tags at all.
-RPrint only the name of the RCS file.
-rrevisionsPrint information about revisions given in the comma-separated list revisions of revisions and ranges. The following table explains the available range formats:
rev1:rev2Revisions rev1 to rev2 (which must be on the same branch).
rev1::rev2The same, but excluding rev1.
:rev::revRevisions from the beginning of the branch up to and including rev.
rev:Revisions starting with rev to the end of the branch containing rev.
rev::Revisions starting just after rev to the end of the branch containing rev.
branchAn argument that is a branch means all revisions on that branch.
branch1:branch2branch1::branch2A range of branches means all revisions on the branches in that range.
branch.The latest revision in branch.
A bare ‘-r’ with no revisions means the latest revision on the default branch, normally the trunk. There can be no space between the ‘-r’ option and its argument.
-SSuppress the header if no revisions are selected.
-s statesPrint information about revisions whose state attributes match one of the states given in the comma-separated list states. Individual states may be any text string, though CVS commonly only uses two states, ‘Exp’ and ‘dead’. See admin options for more information.
-tPrint the same as ‘-h’, plus the descriptive text.
-wloginsPrint information about revisions checked in by users with login names appearing in the comma-separated list logins. If logins is omitted, the user’s login is assumed. There can be no space between the ‘-w’ option and its argument.
log prints the intersection of the revisions
selected with the options ‘-d’, ‘-s’, and
‘-w’, intersected with the union of the revisions
selected by ‘-b’ and ‘-r’.
Since log shows dates in local time,
you might want to see them in Coordinated Universal Time (UTC) or
some other timezone.
To do this you can set your $TZ environment
variable before invoking CVS:
$ TZ=UTC cvs log foo.c $ TZ=EST cvs log bar.c
(If you are using a csh-style shell, like tcsh,
you would need to prefix the examples above with env.)
rls [-e | -l] [-RP] [-r tag[:date]] [-D date] [path…]
rls, repository & working directory for
ls.
dir & list are synonyms for ls and rdir
& rlist are synonyms for rls.
The ls and rls commands are used to list
files and directories in the repository.
By default ls lists the files and directories
that belong in your working directory, what would be
there after an update.
By default rls lists the files and directories
on the tip of the trunk in the topmost directory of the
repository.
Both commands accept an optional list of file and
directory names, relative to the working directory for
ls and the topmost directory of the repository
for rls. Neither is recursive by default.
These standard options are supported by ls & rls:
-dShow dead revisions (with tag when specified).
-eDisplay in CVS/Entries format. This format is meant to remain easily parsable by automation.
-lDisplay all details.
-PDon’t list contents of empty directories when recursing.
-RList recursively.
-r tag[:date]Show files specified by tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See Common command options.
-D dateShow files from date.
$ cvs rls cvs rls: Listing module: `.' CVSROOT first-dir
$ cvs rls CVSROOT cvs rls: Listing module: `CVSROOT' checkoutlist commitinfo config cvswrappers loginfo modules notify rcsinfo taginfo verifymsg
Builds a Larry Wall format patch(1) file between two
releases, that can be fed directly into the patch
program to bring an old release up-to-date with the new
release. (This is one of the few CVS commands that
operates directly from the repository, and doesn’t
require a prior checkout.) The diff output is sent to
the standard output device.
You can specify (using the standard ‘-r’ and ‘-D’ options) any combination of one or two revisions or dates. If only one revision or date is specified, the patch file reflects differences between that revision or date and the current head revisions in the RCS file.
Note that if the software release affected is contained
in more than one directory, then it may be necessary to
specify the ‘-p’ option to the patch command when
patching the old sources, so that patch is able to find
the files that are located in other directories.
These standard options are supported by rdiff
(see Common command options, for a complete description of
them):
-D dateUse the most recent revision no later than date.
-fIf no matching revision is found, retrieve the most recent revision (instead of ignoring the file).
-k kflagProcess keywords according to kflag. See Keyword substitution.
-lLocal; don’t descend subdirectories.
-RExamine directories recursively. This option is on by default.
-r tagUse the revision specified by tag, or when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See Common command options.
In addition to the above, these options are available:
-cUse the context diff format. This is the default format.
-pShow which C function each change is in.
-sCreate a summary change report instead of a patch. The summary includes information about files that were changed or added between the releases. It is sent to the standard output device. This is useful for finding out, for example, which files have changed between two dates or revisions.
-tA diff of the top two revisions is sent to the standard output device. This is most useful for seeing what the last change to a file was.
-uUse the unidiff format for the context diffs.
Remember that old versions
of the patch program can’t handle the unidiff
format, so if you plan to post this patch to the net
you should probably not use ‘-u’.
-V vnExpand keywords according to the rules current in RCS version vn (the expansion format changed with RCS version 5). Note that this option is no longer accepted. CVS will always expand keywords the way that RCS version 5 does.
Suppose you receive mail from foo@example.net asking for an
update from release 1.2 to 1.4 of the tc compiler. You
have no such patches on hand, but with CVS that can
easily be fixed with a command such as this:
$ cvs rdiff -c -r FOO1_2 -r FOO1_4 tc | \ $$ Mail -s 'The patches you asked for' foo@example.net
Suppose you have made release 1.3, and forked a branch called ‘R_1_3fix’ for bug fixes. ‘R_1_3_1’ corresponds to release 1.3.1, which was made some time ago. Now, you want to see how much development has been done on the branch. This command can be used:
$ cvs patch -s -r R_1_3_1 -r R_1_3fix module-name cvs rdiff: Diffing module-name File ChangeLog,v changed from revision 1.52.2.5 to 1.52.2.6 File foo.c,v changed from revision 1.52.2.3 to 1.52.2.4 File bar.h,v changed from revision 1.29.2.1 to 1.2
This command is meant to safely cancel the effect of ‘cvs checkout’. Since CVS doesn’t lock files, it isn’t strictly necessary to use this command. You can always simply delete your working directory, if you like; but you risk losing changes you may have forgotten, and you leave no trace in the CVS history file (see The history file) that you’ve abandoned your checkout.
Use ‘cvs release’ to avoid these problems. This command checks that no uncommitted changes are present; that you are executing it from immediately above a CVS working directory; and that the repository recorded for your files is the same as the repository defined in the module database.
If all these conditions are true, ‘cvs release’ leaves a record of its execution (attesting to your intentionally abandoning your checkout) in the CVS history log.
The release command supports one command option:
-dDelete your working copy of the file if the release succeeds. If this flag is not given your files will remain in your working directory.
WARNING: The release command deletes
all directories and files recursively. This
has the very serious side-effect that any directory
that you have created inside your checked-out sources,
and not added to the repository (using the add
command; see Adding files to a directory) will be silently deleted—even
if it is non-empty!
Before release releases your sources it will
print a one-line message for any file that is not
up-to-date.
U fileP fileThere exists a newer revision of this file in the repository, and you have not modified your local copy of the file (‘U’ and ‘P’ mean the same thing).
A fileThe file has been added to your private copy of the sources, but has not yet been committed to the repository. If you delete your copy of the sources this file will be lost.
R fileThe file has been removed from your private copy of the sources, but has not yet been removed from the repository, since you have not yet committed the removal. See commit—Check files into the repository.
M fileThe file is modified in your working directory. There might also be a newer revision inside the repository.
? filefile is in your working directory, but does not correspond to anything in the source repository, and is not in the list of files for CVS to ignore (see the description of the ‘-I’ option, and see Ignoring files via cvsignore). If you remove your working sources, this file will be lost.
Release the tc directory, and delete your local working copy of the files.
$ cd .. # You must stand immediately above the # sources when you issue ‘cvs release’. $ cvs release -d tc You have [0] altered files in this repository. Are you sure you want to release (and delete) directory `tc': y $
server [-c path]
The CVS server and pserver commands are used to provide
repository access to remote clients and expect a client conversation on
stdin & stdout. Typically these commands are launched from inetd or
via ssh (see Remote repositories).
server expects that the client has already been authenticated somehow,
typically via SSH, and pserver attempts to authenticate the client
itself.
Only one option is available with the server and pserver
commands:
-c pathLoad configuration from the given path rather than from the default location $CVSROOT/CVSROOT/config (see The CVSROOT/config configuration file). path must be /etc/cvs.conf or prefixed by /etc/cvs/. This option is supported beginning with CVS release 1.12.13.
Locates the file module/pa/th,v or module/pa/Attic/th,v and downloads it raw as RCS comma-v file.
Output consists of the real pathname of the comma-v file, relative to the CVS repository, followed by a newline and the binary file content immediately thereafter.
After you’ve run checkout to create your private copy
of source from the common repository, other developers
will continue changing the central source. From time
to time, when it is convenient in your development
process, you can use the update command from
within your working directory to reconcile your work
with any revisions applied to the source repository
since your last checkout or update. Without the -C
option, update will also merge any differences
between the local copy of files and their base revisions
into any destination revisions specified with -r,
-D, or -A.
These standard options are available with update
(see Common command options, for a complete description of
them):
-D dateUse the most recent revision no later than date. This option is sticky, and implies ‘-P’. See Sticky tags, for more information on sticky tags/dates.
-fOnly useful with the ‘-D’ or ‘-r’ flags. If no matching revision is found, retrieve the most recent revision (instead of ignoring the file).
-k kflagProcess keywords according to kflag. See
Keyword substitution.
This option is sticky; future updates of
this file in this working directory will use the same
kflag. The status command can be viewed
to see the sticky options. See Quick reference to CVS commands, for
more information on the status command.
-lLocal; run only in current working directory. See Recursive behavior.
-PPrune empty directories. See Moving and renaming directories.
-pPipe files to the standard output.
-RUpdate directories recursively (default). See Recursive behavior.
-r tag[:date]Retrieve the revisions specified by tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. This option is sticky, and implies ‘-P’. See Sticky tags, for more information on sticky tags/dates. Also see Common command options.
These special options are also available with
update.
-AReset any sticky tags, dates, or ‘-k’ options. See Sticky tags, for more information on sticky tags/dates.
-COverwrite locally modified files with clean copies from the repository (the modified file is saved in .#file.revision, however).
-dCreate any directories that exist in the repository if
they’re missing from the working directory. Normally,
update acts only on directories and files that
were already enrolled in your working directory.
This is useful for updating directories that were created in the repository since the initial checkout; but it has an unfortunate side effect. If you deliberately avoided certain directories in the repository when you created your working directory (either through use of a module name or by listing explicitly the files and directories you wanted on the command line), then updating with ‘-d’ will create those directories, which may not be what you want.
-I nameIgnore files whose names match name (in your working directory) during the update. You can specify ‘-I’ more than once on the command line to specify several files to ignore. Use ‘-I !’ to avoid ignoring any files at all. See Ignoring files via cvsignore, for other ways to make CVS ignore some files.
-WspecSpecify file names that should be filtered during update. You can use this option repeatedly.
spec can be a file name pattern of the same type that you can specify in the .cvswrappers file. See The cvswrappers file.
-jrevisionWith two ‘-j’ options, merge changes from the revision specified with the first ‘-j’ option to the revision specified with the second ‘j’ option, into the working directory.
With one ‘-j’ option, merge changes from the ancestor revision to the revision specified with the ‘-j’ option, into the working directory. The ancestor revision is the common ancestor of the revision which the working directory is based on, and the revision specified in the ‘-j’ option.
Note that using a single ‘-j tagname’ option rather than ‘-j branchname’ to merge changes from a branch will often not remove files which were removed on the branch. See Merging can add or remove files, for more.
In addition, each ‘-j’ option can contain an optional date specification which, when used with branches, can limit the chosen revision to one within a specific date. An optional date is specified by adding a colon (:) to the tag: ‘-jSymbolic_Tag:Date_Specifier’.
update and checkout keep you informed of
their progress by printing a line for each file, preceded
by one character indicating the status of the file:
U fileThe file was brought up to date with respect to the repository. This is done for any file that exists in the repository but not in your working directory, and for files that you haven’t changed but are not the most recent versions available in the repository.
P fileLike ‘U’, but the CVS server sends a patch instead of an entire file. This accomplishes the same thing as ‘U’ using less bandwidth.
A fileThe file has been added to your private copy of the
sources, and will be added to the source repository
when you run commit on the file. This is a
reminder to you that the file needs to be committed.
R fileThe file has been removed from your private copy of the
sources, and will be removed from the source repository
when you run commit on the file. This is a
reminder to you that the file needs to be committed.
M fileThe file is modified in your working directory.
‘M’ can indicate one of two states for a file you’re working on: either there were no modifications to the same file in the repository, so that your file remains as you last saw it; or there were modifications in the repository as well as in your copy, but they were merged successfully, without conflict, in your working directory.
CVS will print some messages if it merges your work,
and a backup copy of your working file (as it looked
before you ran update) will be made. The exact
name of that file is printed while update runs.
C file ¶A conflict was detected while trying to merge your changes to file with changes from the source repository. file (the copy in your working directory) is now the result of attempting to merge the two revisions; an unmodified copy of your file is also in your working directory, with the name .#file.revision where revision is the revision that your modified file started from. Resolve the conflict as described in Conflicts example. (Note that some systems automatically purge files that begin with .# if they have not been accessed for a few days. If you intend to keep a copy of your original file, it is a very good idea to rename it.) Under VMS, the file name starts with __ rather than .#.
? filefile is in your working directory, but does not correspond to anything in the source repository, and is not in the list of files for CVS to ignore (see the description of the ‘-I’ option, and see Ignoring files via cvsignore).
This appendix describes how to invoke CVS, with
references to where each command or feature is
described in detail. For other references run the
cvs --help command, or see Index.
For an alphabetical list of all CVS commands,
see Alphabetical list of all CVS commands).
A CVS command looks like:
cvs [ global_options ] command [ command_options ] [ command_args ]
Global options:
--allow-root=rootdirSpecify acceptable CVSROOT directory (server only). Appeared in CVS 1.10. See Setting up the server for password authentication.
--allow-root-regexp=rootdirSpecify a POSIX extended regular expression which matches acceptable CVSROOT directories (server only). Appeared in CVS 1.12.14. See Setting up the server for password authentication.
-aAuthenticate all communication (client only) (not in CVS 1.9 and older). See Global options.
-bSpecify RCS location (CVS 1.9 and older). See Global options.
-d rootSpecify the CVSROOT. See The Repository.
-e editorEdit messages with editor. See Committing your changes.
-fDo not read the ~/.cvsrc file. See Global options.
-gSet the umask to allow group writable permissions in the working copy. See Global options.
-H--helpPrint a help message. See Global options.
-nDo not change any files. See Global options.
-QBe really quiet. See Global options.
-qBe somewhat quiet. See Global options.
-rMake new working files read-only. See Global options.
-s variable=valueSet a user variable. See Expansions in administrative files.
-T tempdirPut temporary files in tempdir. See Global options.
-tTrace CVS execution. See Global options.
-v--versionDisplay version and copyright information for CVS.
-wMake new working files read-write. See Global options.
-xEncrypt all communication (client only). See Global options.
-z gzip-level ¶Set the compression level (client only). See Global options.
Keyword expansion modes (see Substitution modes):
-kkv $Id: file1,v 1.1 1993/12/09 03:21:13 joe Exp $ -kkvl $Id: file1,v 1.1 1993/12/09 03:21:13 joe Exp harry $ -kk $Id$ -kv file1,v 1.1 1993/12/09 03:21:13 joe Exp -ko no expansion -kb no expansion, file is binary
Keywords (see Keyword List):
$Author: joe $ $Date: 1993/12/09 03:21:13 $ $Mdocdate: December 9 1993 $ $CVSHeader: files/file1,v 1.1 1993/12/09 03:21:13 joe Exp harry $ $Header: /home/files/file1,v 1.1 1993/12/09 03:21:13 joe Exp harry $ $Id: file1,v 1.1 1993/12/09 03:21:13 joe Exp harry $ $Locker: harry $ $Name: snapshot_1_14 $ $RCSfile: file1,v $ $Revision: 1.1 $ $Source: /home/files/file1,v $ $State: Exp $ $Log: file1,v $ Revision 1.1 1993/12/09 03:30:17 joe Initial revision
Commands, command options, and command arguments:
add [options] [files…]Add a new file/directory. See Adding files to a directory.
-k kflagSet keyword expansion.
-m msgSet file description.
admin [options] [files…]Administration of history files in the repository. See admin—Administration front-end for RCS.
-b[rev]Set default branch. See Reverting to the latest vendor release.
-cstringSet comment leader.
-ksubstSet keyword substitution. See Keyword substitution.
-l[rev]Lock revision rev, or latest revision.
-mrev:msgReplace the log message of revision rev with msg.
-orangeDelete revisions from the repository. See admin options.
-qRun quietly; do not print diagnostics.
-sstate[:rev]Set the state. See admin options for more information on possible states.
-tSet file description from standard input.
-tfileSet file description from file.
-t-stringSet file description to string.
-u[rev]Unlock revision rev, or latest revision.
annotate [options] [files…]Show last revision where each line was modified. See annotate—What revision modified each line of a file?.
-D dateAnnotate the most recent revision no later than date. See Common command options.
-FForce annotation of binary files. (Without this option, binary files are skipped with a message.)
-fUse head revision if tag/date not found. See Common command options.
-lLocal; run only in current working directory. See Recursive behavior.
-ROperate recursively (default). See Recursive behavior.
-r tag[:date]Annotate revisions specified by tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See Common command options.
checkout [options] modules…Get a copy of the sources. See checkout—Check out sources for editing.
-AReset any sticky tags/date/options. See Sticky tags and Keyword substitution.
-cOutput the module database. See checkout options.
-D dateCheck out revisions as of date (is sticky). See Common command options.
-d dirCheck out into dir. See checkout options.
-fUse head revision if tag/date not found. See Common command options.
-j tag[:date]Merge in the change specified by tag, or when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See checkout options. Also, see Common command options.
-k kflagUse kflag keyword expansion. See Substitution modes.
-lLocal; run only in current working directory. See Recursive behavior.
-NDon’t “shorten” module paths if -d specified. See checkout options.
-nDo not run module program (if any). See checkout options.
-PPrune empty directories. See Moving and renaming directories.
-pCheck out files to standard output (avoids stickiness). See checkout options.
-ROperate recursively (default). See Recursive behavior.
-r tag[:date]Checkout the revision already tagged with tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See Common command options.
-sLike -c, but include module status. See checkout options.
commit [options] [files…]Check changes into the repository. See commit—Check files into the repository.
-cCheck for valid edits before committing. Requires a CVS client and server both version 1.12.10 or greater.
-F fileRead log message from file. See commit options.
-fForce the file to be committed; disables recursion. See commit options.
-lLocal; run only in current working directory. See Recursive behavior.
-m msgUse msg as log message. See commit options.
-nDo not run module program (if any). See commit options.
-ROperate recursively (default). See Recursive behavior.
-r revCommit to rev. See commit options.
diff [options] [files…]Show differences between revisions. See diff—Show differences between revisions. In addition to the options shown below, accepts a wide variety of options to control output style, for example ‘-c’ for context diffs.
-D date1Diff revision for date against working file. See diff options.
-D date2Diff rev1/date1 against date2. See diff options.
-lLocal; run only in current working directory. See Recursive behavior.
-NInclude diffs for added and removed files. See diff options.
-ROperate recursively (default). See Recursive behavior.
-r tag1[:date1]Diff the revisions specified by tag1 or, when date1 is specified and tag1 is a branch tag, the version from the branch tag1 as it existed on date1, against the working file. See diff options and Common command options.
-r tag2[:date2]Diff the revisions specified by tag2 or, when date2 is specified and tag2 is a branch tag, the version from the branch tag2 as it existed on date2, against rev1/date1. See diff options and Common command options.
edit [options] [files…]Get ready to edit a watched file. See How to edit a file which is being watched.
-a actionsSpecify actions for temporary watch, where
actions is edit, unedit,
commit, all, or none. See
How to edit a file which is being watched.
-cCheck edits: Edit fails if someone else is already editing the file. Requires a CVS client and server both of version 1.12.10 or greater.
-fForce edit; ignore other edits. Added in CVS 1.12.10.
-lLocal; run only in current working directory. See Recursive behavior.
-ROperate recursively (default). See Recursive behavior.
editors [options] [files…]See who is editing a watched file. See Information about who is watching and editing.
-lLocal; run only in current working directory. See Recursive behavior.
-ROperate recursively (default). See Recursive behavior.
export [options] modules…Export files from CVS. See export—Export sources from CVS, similar to checkout.
-D dateCheck out revisions as of date. See Common command options.
-d dirCheck out into dir. See export options.
-fUse head revision if tag/date not found. See Common command options.
-k kflagUse kflag keyword expansion. See Substitution modes.
-lLocal; run only in current working directory. See Recursive behavior.
-NDon’t “shorten” module paths if -d specified. See export options.
-nDo not run module program (if any). See export options.
-ROperate recursively (default). See Recursive behavior.
-r tag[:date]Export the revisions specified by tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See Common command options.
history [options] [files…]Show repository access history. See history—Show repository access history.
-aAll users (default is self). See history options.
-b strBack to record with str in module/file/repos field. See history options.
-cReport on committed (modified) files. See history options.
-D dateSince date. See history options.
-eReport on all record types. See history options.
-lLast modified (committed or modified report). See history options.
-m moduleReport on module (repeatable). See history options.
-n moduleIn module. See history options.
-oReport on checked out modules. See history options.
-p repositoryIn repository. See history options.
-r revSince revision rev. See history options.
-TProduce report on all TAGs. See history options.
-t tagSince tag record placed in history file (by anyone). See history options.
-u userFor user user (repeatable). See history options.
-wWorking directory must match. See history options.
-x typesReport on types, one or more of
TOEFWUPCGMAR. See history options.
-z zoneOutput for time zone zone. See history options.
import [options] repository vendor-tag release-tags…Import files into CVS, using vendor branches. See import—Import sources into CVS, using vendor branches.
-b braImport to vendor branch bra. See Multiple vendor branches.
-dUse the file’s modification time as the time of import. See import options.
-k kflagSet default keyword substitution mode. See import options.
-m msgUse msg for log message. See import options.
-I ignMore files to ignore (! to reset). See import options.
-W specMore wrappers. See import options.
initCreate a CVS repository if it doesn’t exist. See Creating a repository.
kserverKerberos authenticated server. See server & pserver—Act as a server for a client on stdin/stdout. See Direct connection with Kerberos.
log [options] [files…]Print out history information for files. See log—Print out history information for files.
-bOnly list revisions on the default branch. See log options.
-d datesSpecify dates (d1<d2 for range, d for latest before). See log options.
-hOnly print header. See log options.
-lLocal; run only in current working directory. See Recursive behavior.
-NDo not list tags. See log options.
-ROnly print name of RCS file. See log options.
-rrevsOnly list revisions revs. See log options.
-s statesOnly list revisions with specified states. See log options.
-tOnly print header and descriptive text. See log options.
-wloginsOnly list revisions checked in by specified logins. See log options.
loginPrompt for password for authenticating server. See Using the client with password authentication.
logoutRemove stored password for authenticating server. See Using the client with password authentication.
ls [options] [path…]List files available from CVS. See ls & rls—List files in the repository.
-dShow dead revisions (with tag when specified). See ls & rls options.
-eDisplay in CVS/Entries format.
-lDisplay all details.
-PPrune empty directories. See Moving and renaming directories.
-RList recursively. See Recursive behavior.
-D dateShow files from date. See Common command options.
-r revShow files with revision or tag.
pserverPassword authenticated server. See server & pserver—Act as a server for a client on stdin/stdout. See Setting up the server for password authentication.
rannotate [options] [modules…]Show last revision where each line was modified. See annotate—What revision modified each line of a file?.
-D dateAnnotate the most recent revision no later than date. See Common command options.
-FForce annotation of binary files. (Without this option, binary files are skipped with a message.)
-fUse head revision if tag/date not found. See Common command options.
-lLocal; run only in current working directory. See Recursive behavior.
-ROperate recursively (default). See Recursive behavior.
-r tag[:date]Annotate the revision specified by tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See Common command options.
rdiff [options] modules…Show differences between releases. See rdiff—Create ’patch’ format diffs between revisions.
-cContext diff output format (default). See rdiff options.
-D dateSelect revisions based on date. See Common command options.
-fUse head revision if tag/date not found. See Common command options.
-lLocal; run only in current working directory. See Recursive behavior.
-ROperate recursively (default). See Recursive behavior.
-r tag[:date]Select the revisions specified by tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See diff options and Common command options.
-sShort patch - one liner per file. See rdiff options.
-tTop two diffs - last change made to the file. See diff options.
-uUnidiff output format. See rdiff options.
-V versUse RCS Version vers for keyword expansion (obsolete). See rdiff options.
release [options] directories…Indicate that a directory is no longer in use. See release—Indicate that a directory is no longer in use.
-dDelete the given directory. See release options.
remove [options] [files…]Remove an entry from the repository. See Removing files.
-fDelete the file before removing it. See Removing files.
-lLocal; run only in current working directory. See Recursive behavior.
-ROperate recursively (default). See Recursive behavior.
rlog [options] [files…]Print out history information for modules. See log—Print out history information for files.
-bOnly list revisions on the default branch. See log options.
-d datesSpecify dates (d1<d2 for range, d for latest before). See log options.
-hOnly print header. See log options.
-lLocal; run only in current working directory. See Recursive behavior.
-NDo not list tags. See log options.
-ROnly print name of RCS file. See log options.
-rrevsOnly list revisions revs. See log options.
-s statesOnly list revisions with specified states. See log options.
-tOnly print header and descriptive text. See log options.
-wloginsOnly list revisions checked in by specified logins. See log options.
rls [options] [path…]List files in a module. See ls & rls—List files in the repository.
-dShow dead revisions (with tag when specified). See ls & rls options.
-eDisplay in CVS/Entries format.
-lDisplay all details.
-PPrune empty directories. See Moving and renaming directories.
-RList recursively. See Recursive behavior.
-D dateShow files from date. See Common command options.
-r revShow files with revision or tag.
rtag [options] tag modules…Add a symbolic tag to a module. See Specifying what to tag by date or revision. See Creating a branch.
-aClear tag from removed files that would not otherwise be tagged. See Tagging and adding and removing files.
-bCreate a branch named tag. See Branching and merging.
-BUsed in conjunction with -F or -d, enables movement and deletion of branch tags. Use with extreme caution.
-D dateTag revisions as of date. See Specifying what to tag by date or revision.
-dDelete tag. See Deleting, moving, and renaming tags.
-FMove tag if it already exists. See Deleting, moving, and renaming tags.
-fForce a head revision match if tag/date not found. See Specifying what to tag by date or revision.
-lLocal; run only in current working directory. See Recursive behavior.
-nNo execution of tag program. See Common command options.
-ROperate recursively (default). See Recursive behavior.
-r tag[:date]Tag the revision already tagged with tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See Specifying what to tag by date or revision and Common command options.
serverSSH/rsh server. See server & pserver—Act as a server for a client on stdin/stdout. See Connecting with rsh.
suck module/filenameDownload RCS ,v file raw. See suck—Download RCS ,v file raw.
status [options] files…Display status information in a working directory. See File status.
-lLocal; run only in current working directory. See Recursive behavior.
-ROperate recursively (default). See Recursive behavior.
-vInclude tag information for file. See Tags–Symbolic revisions.
tag [options] tag [files…]Add a symbolic tag to checked out version of files. See Specifying what to tag from the working directory. See Creating a branch.
-bCreate a branch named tag. See Branching and merging.
-cCheck that working files are unmodified. See Specifying what to tag from the working directory.
-D dateTag revisions as of date. See Specifying what to tag by date or revision.
-dDelete tag. See Deleting, moving, and renaming tags.
-FMove tag if it already exists. See Deleting, moving, and renaming tags.
-fForce a head revision match if tag/date not found. See Specifying what to tag by date or revision.
-lLocal; run only in current working directory. See Recursive behavior.
-ROperate recursively (default). See Recursive behavior.
-r tag[:date]Tag the revision already tagged with tag, or when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See Specifying what to tag by date or revision and Common command options.
unedit [options] [files…]Undo an edit command. See How to edit a file which is being watched.
-lLocal; run only in current working directory. See Recursive behavior.
-ROperate recursively (default). See Recursive behavior.
update [options] [files…]Bring work tree in sync with repository. See update—Bring work tree in sync with repository.
-AReset any sticky tags/date/options. See Sticky tags and Keyword substitution.
-COverwrite locally modified files with clean copies from the repository (the modified file is saved in .#file.revision, however).
-D dateCheck out revisions as of date (is sticky). See Common command options.
-dCreate directories. See update options.
-fUse head revision if tag/date not found. See Common command options.
-I ignMore files to ignore (! to reset). See import options.
-j tag[:date]Merge in changes from revisions specified by tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See update options.
-k kflagUse kflag keyword expansion. See Substitution modes.
-lLocal; run only in current working directory. See Recursive behavior.
-PPrune empty directories. See Moving and renaming directories.
-pCheck out files to standard output (avoids stickiness). See update options.
-ROperate recursively (default). See Recursive behavior.
-r tag[:date]Checkout the revisions specified by tag or, when date is specified and tag is a branch tag, the version from the branch tag as it existed on date. See Common command options.
-W specMore wrappers. See import options.
version ¶Display the version of CVS being used. If the repository is remote, display both the client and server versions.
watch [on|off|add|remove] [options] [files…]on/off: turn on/off read-only checkouts of files. See Telling CVS to watch certain files.
add/remove: add or remove notification on actions. See Telling CVS to notify you.
-a actionsSpecify actions for temporary watch, where
actions is edit, unedit,
commit, all, or none. See
How to edit a file which is being watched.
-lLocal; run only in current working directory. See Recursive behavior.
-ROperate recursively (default). See Recursive behavior.
watchers [options] [files…]See who is watching a file. See Information about who is watching and editing.
-lLocal; run only in current working directory. See Recursive behavior.
-ROperate recursively (default). See Recursive behavior.
Inside the repository, in the directory $CVSROOT/CVSROOT, there are a number of supportive files for CVS. You can use CVS in a limited fashion without any of them, but if they are set up properly they can help make life easier. For a discussion of how to edit them, see The administrative files.
The most important of these files is the modules file, which defines the modules inside the repository.
The modules file records your definitions of
names for collections of source code. CVS will
use these definitions if you use CVS to update the
modules file (use normal commands like add,
commit, etc).
The modules file may contain blank lines and comments (lines beginning with ‘#’) as well as module definitions. Long lines can be continued on the next line by specifying a backslash (‘\’) as the last character on the line.
There are three basic types of modules: alias modules, regular modules, and ampersand modules. The difference between them is the way that they map files in the repository to files in the working directory. In all of the following examples, the top-level repository contains a directory called first-dir, which contains two files, file1 and file2, and a directory sdir. first-dir/sdir contains a file sfile.
Alias modules are the simplest kind of module:
mname -a aliases…This represents the simplest way of defining a module
mname. The ‘-a’ flags the definition as a
simple alias: CVS will treat any use of mname (as
a command argument) as if the list of names
aliases had been specified instead.
aliases may contain either other module names or
paths. When you use paths in aliases, checkout
creates all intermediate directories in the working
directory, just as if the path had been specified
explicitly in the CVS arguments.
For example, if the modules file contains:
amodule -a first-dir
then the following two commands are equivalent:
$ cvs co amodule $ cvs co first-dir
and they each would provide output such as:
cvs checkout: Updating first-dir U first-dir/file1 U first-dir/file2 cvs checkout: Updating first-dir/sdir U first-dir/sdir/sfile
mname [ options ] dir [ files… ]In the simplest case, this form of module definition
reduces to ‘mname dir’. This defines
all the files in directory dir as module mname.
dir is a relative path (from $CVSROOT) to a
directory of source in the source repository. In this
case, on checkout, a single directory called
mname is created as a working directory; no
intermediate directory levels are used by default, even
if dir was a path involving several directory
levels.
For example, if a module is defined by:
regmodule first-dir
then regmodule will contain the files from first-dir:
$ cvs co regmodule cvs checkout: Updating regmodule U regmodule/file1 U regmodule/file2 cvs checkout: Updating regmodule/sdir U regmodule/sdir/sfile $
By explicitly specifying files in the module definition after dir, you can select particular files from directory dir. Here is an example:
regfiles first-dir/sdir sfile
With this definition, getting the regfiles module will create a single working directory regfiles containing the file listed, which comes from a directory deeper in the CVS source repository:
$ cvs co regfiles U regfiles/sfile $
A module definition can refer to other modules by including ‘&module’ in its definition.
mname [ options ] &module...
Then getting the module creates a subdirectory for each such module, in the directory containing the module. For example, if modules contains
ampermod &first-dir
then a checkout will create an ampermod directory
which contains a directory called first-dir,
which in turns contains all the directories and files
which live there. For example, the command
$ cvs co ampermod
will create the following files:
ampermod/first-dir/file1 ampermod/first-dir/file2 ampermod/first-dir/sdir/sfile
There is one quirk/bug: the messages that CVS prints omit the ampermod, and thus do not correctly display the location to which it is checking out the files:
$ cvs co ampermod cvs checkout: Updating first-dir U first-dir/file1 U first-dir/file2 cvs checkout: Updating first-dir/sdir U first-dir/sdir/sfile $
Do not rely on this buggy behavior; it may get fixed in a future release of CVS.
An alias module may exclude particular directories from other modules by using an exclamation mark (‘!’) before the name of each directory to be excluded.
For example, if the modules file contains:
exmodule -a !first-dir/sdir first-dir
then checking out the module ‘exmodule’ will check out everything in ‘first-dir’ except any files in the subdirectory ‘first-dir/sdir’.
Either regular modules or ampersand modules can contain options, which supply additional information concerning the module.
-d name ¶Name the working directory something other than the module name.
-e prog ¶Specify a program prog to run whenever files in a module are exported. prog runs with a single argument, the module name.
-o prog ¶Specify a program prog to run whenever files in a module are checked out. prog runs with a single argument, the module name. See How the modules file “program options” programs are run for information on how prog is called.
-s status ¶Assign a status to the module. When the module file is printed with ‘cvs checkout -s’ the modules are sorted according to primarily module status, and secondarily according to the module name. This option has no other meaning. You can use this option for several things besides status: for instance, list the person that is responsible for this module.
-t prog ¶Specify a program prog to run whenever files in a
module are tagged with rtag. prog runs
with two arguments: the module name and the symbolic
tag specified to rtag. It is not run
when tag is executed. Generally you will find
that the taginfo file is a better solution (see Taginfo).
You should also see see How the modules file “program options” programs are run about how the “program options” programs are run.
For checkout, rtag, and export, the program is server-based, and as such the following applies:-
If using remote access methods (pserver, ext, etc.), CVS will execute this program on the server from a temporary directory. The path is searched for this program.
If using “local access” (on a local or remote NFS filesystem, i.e. repository set just to a path), the program will be executed from the newly checked-out tree, if found there, or alternatively searched for in the path if not.
The programs are all run after the operation has effectively completed.
Wrappers refers to a CVS feature which lets you control certain settings based on the name of the file which is being operated on. The settings are ‘-k’ for binary files, and ‘-m’ for nonmergeable text files.
The ‘-m’ option
specifies the merge methodology that should be used when
a non-binary file is updated. MERGE means the usual
CVS behavior: try to merge the files. COPY
means that cvs update will refuse to merge
files, as it also does for files specified as binary
with ‘-kb’ (but if the file is specified as
binary, there is no need to specify ‘-m 'COPY'’).
CVS will provide the user with the
two versions of the files, and require the user using
mechanisms outside CVS, to insert any necessary
changes.
WARNING: do not use COPY with
CVS 1.9 or earlier - such versions of CVS will
copy one version of your file over the other, wiping
out the previous contents.
The ‘-m’ wrapper option only affects behavior when
merging is done on update; it does not affect how files
are stored. See Handling binary files, for more on
binary files.
The basic format of the file cvswrappers is:
wildcard [option value][option value]... where option is one of -m update methodology value: MERGE or COPY -k keyword expansion value: expansion mode and value is a single-quote delimited value.
For example, the following command imports a directory, treating files whose name ends in ‘.exe’ as binary:
cvs import -I ! -W "*.exe -k 'b'" first-dir vendortag reltag
Several of the administrative files support triggers, or the launching external scripts or programs at specific times before or after particular events, during the execution of CVS commands. These hooks can be used to prevent certain actions, log them, and/or maintain anything else you deem practical.
All the trigger scripts are launched in a copy of the user sandbox being committed, on the server, in client-server mode. In local mode, the scripts are actually launched directly from the user sandbox directory being committed. For most intents and purposes, the same scripts can be run in both locations without alteration.
The administrative files such as commitinfo, loginfo, rcsinfo, verifymsg, etc., all have a common format. The purpose of the files are described later on. The common syntax is described here.
Each line contains the following:
Blank lines are ignored. Lines that start with the character ‘#’ are treated as comments. Long lines unfortunately can not be broken in two parts in any way.
The first regular expression that matches the current directory name in the repository or the first line containing ‘DEFAULT’ in lieu of a regular expression is used and all lines containing ‘ALL’ is used for the hooks which support the ‘ALL’ keyword. The rest of the line is used as a file name or command-line template as appropriate. See the descriptions of the individual script hooks for information on whether the ‘ALL’ keyword is supported (see The Trigger Scripts).
Note: The following information on format strings is valid
as long as the line UseNewInfoFmtStrings=yes appears in
your repository’s config file (see The CVSROOT/config configuration file). Otherwise,
default format strings may be appended to the command line and
the ‘loginfo’ file, especially, can exhibit slightly
different behavior. For more information,
See Updating legacy repositories to stop using deprecated command line template formats.
In the cases where the second segment of the matched line is a command line template (e.g. commitinfo, loginfo, & verifymsg), the command line template may contain format strings which will be replaced with specific values before the script is run.
Format strings can represent a single variable or one or more attributes of a list variable. An example of a list variable would be the list available to scripts hung on the loginfo hooks - the list of files which were just committed. In the case of loginfo, three attributes are available for each list item: file name, precommit version, and postcommit version.
Format strings consist of a ‘%’ character followed by an optional ‘{’ (required in the multiple list attribute case), a single format character representing a variable or a single attribute of list elements or multiple format characters representing attributes of list elements, and a closing ‘}’ when the open bracket was present.
Flat format strings, or single format characters which get replaced with a single value, will generate a single argument to the called script, regardless of whether the replacement variable contains white space or other special characters.
List attributes will generate an argument for each attribute requested for each list item. For example, ‘%{sVv}’ in a loginfo command template will generate three arguments (file name, precommit version, postcommit version, ...) for each file committed. As in the flat format string case, each attribute will be passed in as a single argument regardless of whether it contains white space or other special characters.
‘%%’ will be replaced with a literal ‘%’.
The format strings available to all script hooks are:
cThe canonical name of the command being executed. For instance, in the case of
a hook run from cvs up, CVS would replace ‘%c’ with the string
‘update’ and, in the case of a hook run from cvs ci, CVS would
replace ‘%c’ with the string ‘commit’.
nThe null, or empty, string.
pThe name of the directory being operated on within the repository.
rThe name of the repository (the path portion of $CVSROOT).
ROn a server, the name of the referrer, if any. The referrer is the CVSROOT the client reports it used to contact a server which then referred it to this server. Should usually be set on a primary server with a write proxy setup.
Other format strings are file specific. See the docs on the particular script hooks for more information (see The Trigger Scripts).
As an example, the following line in a loginfo file would match only the directory module and any subdirectories of module:
^module\(/\|$\) (echo; echo %p: %{sVv}; cat) >>$CVSROOT/CVSROOT/commitlog
Using this same line and assuming a commit of new revisions 1.5.4.4 and 1.27.4.1 based on old revisions 1.5.4.3 and 1.27, respectively, of file1 and file2 in module, something like the following log message should be appended to commitlog:
module file1 1.5.4.3 1.5.4.4 file2 1.27 1.27.4.1 Update of /cvsroot/module In directory localhost.localdomain:/home/jrandom/work/module Modified Files: file1 file2 Log Message: A log message.
Security is a huge subject, and implementing a secure system is a non-trivial task. This section will barely touch on all the issues involved, but it is well to note that, as with any script you will be allowing an untrusted user to run on your server, there are measures you can take to help prevent your trigger scripts from being abused.
For instance, since the CVS trigger scripts all run in a copy of the user’s sandbox on the server, a naively coded Perl trigger script which attempts to use a Perl module that is not installed on the system can be hijacked by any user with commit access who is checking in a file with the correct name. Other scripting languages may be vulnerable to similar hacks.
One way to make a script more secure, at least with Perl, is to use scripts
which invoke the -T, or "taint-check" switch on their #! line.
In the most basic terms, this causes Perl to avoid running code that may have
come from an external source. Please run the perldoc perlsec command
for more on Perl security. Again, other languages may implement other security
verification hooks which look more or less like Perl’s "taint-check" mechanism.
The ‘-i’ flag in the modules file can be used to run a certain program whenever files are committed (see The modules file). The files described in this section provide other, more flexible, ways to run programs whenever something is committed.
There are three kinds of programs that can be run on commit. They are specified in files in the repository, as described below. The following table summarises the file names and the purpose of the corresponding programs.
The program is responsible for checking that the commit is allowed. If it exits with a non-zero exit status the commit will be aborted. See Commitinfo.
The specified program is used to evaluate the log message, and possibly verify that it contains all required fields. This is most useful in combination with the rcsinfo file, which can hold a log message template (see Rcsinfo). See Verifying log messages.
The specified program is called when the commit is complete. It receives the log message and some additional information and can store the log message in a file, or mail it to appropriate persons, or maybe post it to a local newsgroup, or… Your imagination is the limit! See Loginfo.
New repositories are created set to use the new format strings by default, so if you are creating a new repository, you shouldn’t have to worry about this section.
If you are attempting to maintain a legacy repository which was making use of the commitinfo, editinfo, verifymsg, loginfo, and/or taginfo script hooks, you should have no immediate problems with using the current CVS executable, but your users will probably start to see deprecation warnings.
The reason for this is that all of the script hooks have been updated to use a new command line parser that extensibly supports multiple loginfo & notify style format strings (see The common syntax) and this support is not completely compatible with the old style format strings.
The quick upgrade method is to stick a ‘1’ after each format string in your old loginfo file. For example:
DEFAULT (echo ""; id; echo %{sVv}; date; cat) >> $CVSROOT/CVSROOT/commitlog
would become:
DEFAULT (echo ""; id; echo %1{sVv}; date; cat) >> $CVSROOT/CVSROOT/commitlog
If you were counting on the fact that only the first ‘%’ in the line was replaced as a format string, you may also have to double up any further percent signs on the line.
If you did this all at once and checked it in, everything should still be running properly.
Now add the following line to your config file (see The CVSROOT/config configuration file):
UseNewInfoFmtStrings=yes
Everything should still be running properly, but your users will probably start seeing new deprecation warnings.
Dealing with the deprecation warnings now generated by commitinfo, editinfo, verifymsg, and taginfo should be easy. Simply specify what are currently implicit arguments explicitly. This means appending the following strings to each active command line template in each file:
commitinfo‘ %r/%p %s’
editinfo‘ %l’
taginfo‘ %t %o %p %{sv}’
verifymsg‘ %l’
If you don’t desire that any of the newly available information be passed to the scripts hanging off of these hooks, no further modifications to these files should be necessary to insure current and future compatibility with CVS’s format strings.
Fixing loginfo could be a little tougher. The old style loginfo format strings caused a single space and comma separated argument to be passed in in place of the format string. This is what will continue to be generated due to the deprecated ‘1’ you inserted into the format strings.
Since the new format separates each individual item and passes it into the script as a separate argument (for a good reason - arguments containing commas and/or white space are now parsable), to remove the deprecated ‘1’ from your loginfo command line templates, you will most likely have to rewrite any scripts called by the hook to handle the new argument format.
Also note that the way ‘%’ followed by unrecognised characters and by ‘{}’ was treated in past versions of CVS is not strictly adhered to as there were bugs in the old versions. Specifically, ‘%{}’ would eat the next character and unrecognised strings resolved only to the empty string, which was counter to what was stated in the documentation. This version will do what the documentation said it should have (if you were using only some combination of ‘%{sVv}’, e.g. ‘%{sVv}’, ‘%{sV}’, or ‘%v’, you should have no troubles).
On the bright side, you should have plenty of time to do this before all support for the old format strings is removed from CVS, so you can just put up with the deprecation warnings for awhile if you like.
The commitinfo file defines programs to execute whenever ‘cvs commit’ is about to execute. These programs are used for pre-commit checking to verify that the modified, added and removed files are really ready to be committed. This could be used, for instance, to verify that the changed files conform to to your site’s standards for coding practice.
The commitinfo file has the standard form for script hooks (see The Trigger Scripts), where each line is a regular expression followed by a command to execute. It supports only the DEFAULT keywords.
In addition to the common format strings (see The common syntax), commitinfo supports:
{s}a list of the names of files to be committed
Currently, if no format strings are specified, a default string of ‘ %r/%p %{s}’ will be appended to the command line template before replacement is performed, but this feature is deprecated. It is simply in place so that legacy repositories will remain compatible with the new CVS application. For information on updating, see Updating legacy repositories to stop using deprecated command line template formats.
The first line with a regular expression matching the directory within the repository will be used. If the command returns a non-zero exit status the commit will be aborted.
The command will be run in the root of the workspace containing the new versions of any files the user would like to modify (commit), or in a copy of the workspace on the server (see Remote repositories). If a file is being removed, there will be no copy of the file under the current directory. If a file is being added, there will be no corresponding archive file in the repository unless the file is being resurrected.
Note that both the repository directory and the corresponding Attic (see The attic) directory may need to be checked to locate the archive file corresponding to any given file being committed. Much of the information about the specific commit request being made, including the destination branch, commit message, and command line options specified, is not available to the command.
Once you have entered a log message, you can evaluate that message to check for specific content, such as a bug ID. Use the verifymsg file to specify a program that is used to verify the log message. This program could be a simple script that checks that the entered message contains the required fields.
The verifymsg file is often most useful together with the rcsinfo file, which can be used to specify a log message template (see Rcsinfo).
The verifymsg file has the standard form for script hooks (see The Trigger Scripts), where each line is a regular expression followed by a command to execute. It supports only the DEFAULT keywords.
In addition to the common format strings (see The common syntax), verifymsg supports:
lthe full path to the file containing the log message to be verified
{sV}File attributes, where:
sfile name
Vold version number (pre-checkin)
Currently, if no format strings are specified, a default string of ‘ %l’ will be appended to the command line template before replacement is performed, but this feature is deprecated. It is simply in place so that legacy repositories will remain compatible with the new CVS application. For information on updating, see Updating legacy repositories to stop using deprecated command line template formats.
One thing that should be noted is that the ‘ALL’ keyword is not supported. If more than one matching line is found, the first one is used. This can be useful for specifying a default verification script in a directory, and then overriding it in a subdirectory.
If the verification script exits with a non-zero exit status, the commit is aborted.
In the default configuration, CVS allows the verification script to change the log message. This is controlled via the RereadLogAfterVerify CVSROOT/config option.
When ‘RereadLogAfterVerify=always’ or ‘RereadLogAfterVerify=stat’, the log message will either always be reread after the verification script is run or reread only if the log message file status has changed.
See The CVSROOT/config configuration file, for more on CVSROOT/config options.
It is NOT a good idea for a verifymsg script to
interact directly with the user in the various
client/server methods. For the pserver method,
there is no protocol support for communicating between
verifymsg and the client on the remote end. For the
ext and server methods, it is possible
for CVS to become confused by the characters going
along the same channel as the CVS protocol
messages. See Remote repositories, for more
information on client/server setups. In addition, at the time
the verifymsg script runs, the CVS
server has locks in place in the repository. If control is
returned to the user here then other users may be stuck waiting
for access to the repository.
This option can be useful if you find yourself using an rcstemplate that needs to be modified to remove empty elements or to fill in default values. It can also be useful if the rcstemplate has changed in the repository and the CVS/Template was not updated, but is able to be adapted to the new format by the verification script that is run by verifymsg.
An example of an update might be to change all occurrences of ’BugId:’ to be ’DefectId:’ (which can be useful if the rcstemplate has recently been changed and there are still checked-out user trees with cached copies in the CVS/Template file of the older version).
Another example of an update might be to delete a line that contains ’BugID: none’ from the log message after validation of that value as being allowed is made.
The following is a little silly example of a verifymsg file, together with the corresponding rcsinfo file, the log message template and a verification script. We begin with the log message template. We want to always record a bug-id number on the first line of the log message. The rest of log message is free text. The following template is found in the file /usr/cvssupport/tc.template.
BugId:
The script /usr/cvssupport/bugid.verify is used to evaluate the log message.
#!/bin/sh
#
# bugid.verify filename
#
# Verify that the log message contains a valid bugid
# on the first line.
#
if sed 1q < $1 | grep '^BugId:[ ]*[0-9][0-9]*$' > /dev/null; then
exit 0
elif sed 1q < $1 | grep '^BugId:[ ]*none$' > /dev/null; then
# It is okay to allow commits with 'BugId: none',
# but do not put that text into the real log message.
grep -v '^BugId:[ ]*none$' > $1.rewrite
mv $1.rewrite $1
exit 0
else
echo "No BugId found."
exit 1
fi
The verifymsg file contains this line:
^tc /usr/cvssupport/bugid.verify %l
The rcsinfo file contains this line:
^tc /usr/cvssupport/tc.template
The config file contains this line:
RereadLogAfterVerify=always
The loginfo file is used to control where log information is sent after
versioned changes are made to repository archive files and after directories
are added to the repository. Logging tags for how to log tagging
information and Logging admin commands for how to log changes due to the admin
command.
The loginfo file has the standard form for script hooks (see The Trigger Scripts), where each line is a regular expression followed by a command to execute. It supports the ALL and DEFAULT keywords.
Any specified scripts are called:
commitOnce per directory, immediately after a successfully completing the commit of all files within that directory.
importOnce per import, immediately after completion of all write operations.
addImmediately after the successful add of a directory.
Any script called via loginfo will be fed the log information on its standard input. Note that the filter program must read all of the log information from its standard input or CVS may fail with a broken pipe signal.
In addition to the common format strings (see The common syntax), loginfo supports:
{sVv}File attributes, where:
sfile name
Vold version number (pre-checkin)
vnew version number (post-checkin)
For example, some valid format strings are ‘%%’, ‘%s’, ‘%{s}’, and ‘%{sVv}’.
Currently, if ‘UseNewInfoFmtStrings’ is not set in the config administration file (see The CVSROOT/config configuration file), the format strings will be substituted as they were in past versions of CVS, but this feature is deprecated. It is simply in place so that legacy repositories will remain compatible with the new CVS application. For information on updating, please see Updating legacy repositories to stop using deprecated command line template formats.
As an example, if ‘/u/src/master/yoyodyne/tc’ is the repository, ‘%p’
and ‘%{sVv}’ are the format strings, and three files (ChangeLog,
Makefile, foo.c) were modified, the output might be:
yoyodyne/tc ChangeLog 1.1 1.2 Makefile 1.3 1.4 foo.c 1.12 1.13
Note: when CVS is accessing a remote repository, loginfo will be run on the remote (i.e., server) side, not the client side (see Remote repositories).
The following loginfo file, together with the
tiny shell-script below, appends all log messages
to the file $CVSROOT/CVSROOT/commitlog,
and any commits to the administrative files (inside
the CVSROOT directory) are also logged in
/usr/adm/cvsroot-log.
Commits to the prog1 directory are mailed to ceder.
ALL /usr/local/bin/cvs-log $CVSROOT/CVSROOT/commitlog $USER ^CVSROOT\(/\|$\) /usr/local/bin/cvs-log /usr/adm/cvsroot-log $USER ^prog1\(/\|$\) Mail -s "%p %s" ceder
The shell-script /usr/local/bin/cvs-log looks like this:
#!/bin/sh (echo "------------------------------------------------------"; echo -n "$2 "; date; echo; cat) >> $1
It is often useful to maintain a directory tree which contains files which correspond to the latest version in the repository. For example, other developers might want to refer to the latest sources without having to check them out, or you might be maintaining a web site with CVS and want every checkin to cause the files used by the web server to be updated.
The way to do this is by having loginfo invoke
cvs update. Doing so in the naive way will
cause a problem with locks, so the cvs update
must be run in the background.
Here is an example for unix (this should all be on one line):
^cyclic-pages\(/\|$\) (date; cat; (sleep 2; cd /u/www/local-docs; cvs -q update -d) &) >> $CVSROOT/CVSROOT/updatelog 2>&1
This will cause checkins to repository directory cyclic-pages
and its subdirectories to update the checked
out tree in /u/www/local-docs.
The postadmin file defines programs to execute after an admin
command modifies files. The postadmin file has the standard form
for script hooks (see The Trigger Scripts), where each line is a regular
expression followed by a command to execute. It supports the ALL and DEFAULT
keywords.
The postadmin file supports no format strings other than the common ones (see The common syntax),
The taginfo file defines programs to execute
when someone executes a tag or rtag
command. The taginfo file has the standard form
for script hooks (see The Trigger Scripts), where each line
is a regular expression followed by a command to execute.
It supports the ALL and DEFAULT keywords.
In addition to the common format strings (see The common syntax), taginfo supports:
btag type (T for branch, N for not-branch, or ? for
unknown, as during delete operations)
ooperation (add for tag, mov for tag -F, or
del for tag -d)
tnew tag name
{sTVv}file attributes, where:
sfile name
Ttag name of destination, or the empty string when there is no associated tag name (this usually means the trunk)
Vold version number (for a move or delete operation)
vnew version number (for an add or move operation)
For example, some valid format strings are ‘%%’, ‘%p’, ‘%t’, ‘%s’, ‘%{s}’, and ‘%{sVv}’.
Currently, if no format strings are specified, a default string of ‘ %t %o %p %{sv}’ will be appended to the command line template before replacement is performed, but this feature is deprecated. It is simply in place so that legacy repositories will remain compatible with the new CVS application. For information on updating, see Updating legacy repositories to stop using deprecated command line template formats.
A non-zero exit of the filter program will cause the tag to be aborted.
Here is an example of using taginfo to log tag and rtag
commands. In the taginfo file put:
ALL /usr/local/cvsroot/CVSROOT/loggit %t %b %o %p %{sVv}
Where /usr/local/cvsroot/CVSROOT/loggit contains the following script:
#!/bin/sh echo "$@" >>/home/kingdon/cvsroot/CVSROOT/taglog
The posttag file defines programs to execute after a tag or
rtag command modifies files. The posttag file has the standard
form for script hooks (see The Trigger Scripts), where each line is a regular
expression followed by a command to execute. It supports the ALL and DEFAULT
keywords.
The posttag admin file supports the same format strings as the taginfo file (see Taginfo),
The postwatch file defines programs to execute after any command (for
instance, watch, edit, unedit, or commit) modifies
any CVS/fileattr file in the repository (see Mechanisms to track who is editing files). The
postwatch file has the standard form for script hooks
(see The Trigger Scripts), where each line is a regular expression followed by
a command to execute. It supports the ALL and DEFAULT keywords.
The postwatch file supports no format strings other than the common
ones (see The common syntax), but it is worth noting that the %c format string
may not be replaced as you might expect. Client runs of edit and
unedit can sometimes skip contacting the CVS server and cache the
notification of the file attribute change to be sent the next time the client
contacts the server for whatever other reason,
The preproxy file defines programs to execute after a secondary server receives a write request from a client, just before it starts up the primary server and becomes a write proxy. This hook could be used to dial a modem, launch an SSH tunnel, establish a VPN, or anything else that might be necessary to do before contacting the primary server.
preproxy scripts are called once, at the time of the write request, with the repository argument (if requested) set from the topmost directory sent by the client.
The preproxy file has the standard form for script hooks (see The Trigger Scripts), where each line is a regular expression followed by a command to execute. It supports the ALL and DEFAULT keywords.
In addition to the common format strings, the preproxy file supports the following format string:
Pthe CVSROOT string which specifies the primary server
The postproxy file defines programs to execute after a secondary server notes that the connection to the primary server has shut down and before it releases the client by shutting down the connection to the client. This could hook could be used to disconnect a modem, an SSH tunnel, a VPN, or anything else that might be necessary to do after contacting the primary server. This hook should also be used to pull updates from the primary server before allowing the client which did the write to disconnect since otherwise the client’s next read request may generate error messages and fail upon encountering an out of date repository on the secondary server.
postproxy scripts are called once per directory.
The postproxy file has the standard form for script hooks (see The Trigger Scripts), where each line is a regular expression followed by a command to execute. It supports the ALL and DEFAULT keywords.
In addition to the common format strings, the postproxy file supports the following format string:
Pthe CVSROOT string which specifies the primary server
The rcsinfo file can be used to specify a form to edit when filling out the commit log. The rcsinfo file has a syntax similar to the verifymsg, commitinfo and loginfo files. See The common syntax. Unlike the other files the second part is not a command-line template. Instead, the part after the regular expression should be a full pathname to a file containing the log message template.
If the repository name does not match any of the regular expressions in this file, the ‘DEFAULT’ line is used, if it is specified.
All occurrences of the name ‘ALL’ appearing as a regular expression are used in addition to the first matching regular expression or ‘DEFAULT’.
The log message template will be used as a default log message. If you specify a log message with ‘cvs commit -m message’ or ‘cvs commit -f file’ that log message will override the template.
See Verifying log messages, for an example rcsinfo file.
When CVS is accessing a remote repository, the contents of rcsinfo at the time a directory is first checked out will specify a template. This template will be updated on all ‘cvs update’ commands. It will also be added to new directories added with a ‘cvs add new-directory’ command. In versions of CVS prior to version 1.12, the CVS/Template file was not updated. If the CVS server is at version 1.12 or higher an older client may be used and the CVS/Template will be updated from the server.
There are certain file names that frequently occur inside your working copy, but that you don’t want to put under CVS control. Examples are all the object files that you get while you compile your sources. Normally, when you run ‘cvs update’, it prints a line for each file it encounters that it doesn’t know about (see update output).
CVS has a list of files (or sh(1) file name patterns)
that it should ignore while running update,
import and release.
This list is constructed in the following way.
RCS SCCS CVS CVS.adm
RCSLOG cvslog.*
tags TAGS
.make.state .nse_depinfo
*~ #* .#* ,* _$* *$
*.old *.bak *.BAK *.orig *.rej .del-*
*.a *.olb *.o *.obj *.so *.exe
*.Z *.elc *.ln
core
$CVSIGNORE is appended to the list.
In any of the 5 places listed above, a single exclamation mark (‘!’) clears the ignore list. This can be used if you want to store any file which normally is ignored by CVS.
Specifying ‘-I !’ to cvs import will import
everything, which is generally what you want to do if
you are importing files from a pristine distribution or
any other source which is known to not contain any
extraneous files. However, looking at the rules above
you will see there is a fly in the ointment; if the
distribution contains any .cvsignore files, then
the patterns from those files will be processed even if
‘-I !’ is specified. The only workaround is to
remove the .cvsignore files in order to do the
import. Because this is awkward, in the future
‘-I !’ might be modified to override
.cvsignore files in each directory.
Note that the syntax of the ignore files consists of a series of lines, each of which contains a space separated list of filenames. This offers no clean way to specify filenames which contain spaces, but you can use a workaround like foo?bar to match a file named foo bar (it also matches fooxbar and the like). Also note that there is currently no way to specify comments.
It may be helpful to use CVS to maintain your own files in the CVSROOT directory. For example, suppose that you have a script logcommit.pl which you run by including the following line in the commitinfo administrative file:
ALL $CVSROOT/CVSROOT/logcommit.pl %r/%p %s
To maintain logcommit.pl with CVS you would add the following line to the checkoutlist administrative file:
logcommit.pl
The format of checkoutlist is one line for each file that you want to maintain using CVS, giving the name of the file, followed optionally by more whitespace and any error message that should print if the file cannot be checked out into CVSROOT after a commit:
logcommit.pl Could not update CVSROOT/logcommit.pl.
After setting up checkoutlist in this fashion, the files listed there will function just like CVS’s built-in administrative files. For example, when checking in one of the files you should get a message such as:
cvs commit: Rebuilding administrative file database
and the checked out copy in the CVSROOT directory should be updated.
Note that listing passwd (see Setting up the server for password authentication) in checkoutlist is not recommended for security reasons.
For information about keeping a checkout out copy in a more general context than the one provided by checkoutlist, see Keeping a checked out copy.
By default, the file $CVSROOT/CVSROOT/history is used
to log information for the history command (see history—Show repository access history).
This file name may be changed with the ‘HistoryLogPath’ and
‘HistorySearchPath’ config options (see The CVSROOT/config configuration file).
The file format of the history file is
documented only in comments in the CVS source
code, but generally programs should use the cvs
history command to access it anyway, in case the
format changes with future releases of CVS.
Sometimes in writing an administrative file, you might want the file to be able to know various things based on environment CVS is running in. There are several mechanisms to do that.
To find the home directory of the user running CVS
(from the HOME environment variable), use
‘~’ followed by ‘/’ or the end of the line.
Likewise for the home directory of user, use
‘~user’. These variables are expanded on
the server machine, and don’t get any reasonable
expansion if pserver (see Direct connection with password authentication)
is in use; therefore user variables (see below) may be
a better choice to customise behavior based on the user
running CVS.
One may want to know about various pieces of
information internal to CVS. A CVS internal
variable has the syntax ${variable},
where variable starts with a letter and consists
of alphanumeric characters and ‘_’. If the
character following variable is a
non-alphanumeric character other than ‘_’, the
‘{’ and ‘}’ can be omitted. The CVS
internal variables are:
CVSROOT ¶This is the absolute path to the current CVS root directory. See The Repository, for a description of the various ways to specify this, but note that the internal variable contains just the directory and not any of the access method information.
RCSBIN ¶In CVS 1.9.18 and older, this specified the directory where CVS was looking for RCS programs. Because CVS no longer runs RCS programs, specifying this internal variable is now an error.
CVSEDITOR ¶EDITORVISUALThese all expand to the same value, which is the editor that CVS is using. See Global options, for how to specify this.
USER ¶Username of the user running CVS (on the CVS server machine). When using pserver, this is the user specified in the repository specification which need not be the same as the username the server is running as (see Setting up the server for password authentication). Do not confuse this with the environment variable of the same name.
SESSIONID ¶Unique Session ID of the CVS process. This is a random string of printable characters of at least 16 characters length. Users should assume that it may someday grow to at most 256 characters in length.
COMMITID ¶Unique Session ID of the CVS process. This is a random string of printable characters of at least 16 characters length. Users should assume that it may someday grow to at most 256 characters in length. Currently, Debian and MirBSD CVS uses 19 characters.
If you want to pass a value to the administrative files
which the user who is running CVS can specify,
use a user variable.
To expand a user variable, the
administrative file contains
${=variable}. To set a user variable,
specify the global option ‘-s’ to CVS, with
argument variable=value. It may be
particularly useful to specify this option via
.cvsrc (see Default options and the ~/.cvsrc file).
For example, if you want the administrative file to
refer to a test directory you might create a user
variable TESTDIR. Then if CVS is invoked
as
cvs -s TESTDIR=/work/local/tests
and the
administrative file contains sh
${=TESTDIR}/runtests, then that string is expanded
to sh /work/local/tests/runtests.
All other strings containing ‘$’ are reserved; there is no way to quote a ‘$’ character so that ‘$’ represents itself.
Environment variables passed to administrative files are:
CVS_USER ¶The CVS-specific username provided by the user, if it
can be provided (currently just for the pserver access
method), and to the empty string otherwise. (CVS_USER
and USER may differ when $CVSROOT/CVSROOT/passwd
is used to map CVS usernames to system usernames.)
LOGNAME ¶The username of the system user.
USER ¶Same as LOGNAME.
Do not confuse this with the internal variable of the same name.
Usually, the config file is found at $CVSROOT/CVSROOT/config,
but this may be overridden on the pserver and server command
lines (see server & pserver—Act as a server for a client on stdin/stdout).
The administrative file config contains various miscellaneous settings which affect the behavior of CVS. The syntax is slightly different from the other administrative files.
Leading white space on any line is ignored, though the syntax is very strict and will reject spaces and tabs almost anywhere else.
Empty lines, lines containing nothing but white space, and lines which start with ‘#’ (discounting any leading white space) are ignored.
Other lines consist of the optional leading white space, a keyword, ‘=’, and a value. Please note again that this syntax is very strict. Extraneous spaces or tabs, other than the leading white space, are not permitted on these lines.
As of CVS 1.12.13, lines of the form ‘[CVSROOT]’ mark the subsequent section of the config file as applying only to certain repositories. Multiple ‘[CVSROOT]’ lines without intervening ‘KEYWORD=VALUE’ pairs cause processing to fall through, processing subsequent keywords for any root in the list. Finally, keywords and values which appear before any ‘[CVSROOT]’ lines are defaults, and may to apply to any repository. For example, consider the following file:
# Defaults LogHistory=TMAR [/cvsroots/team1] LockDir=/locks/team1 [/cvsroots/team2] LockDir=/locks/team2 [/cvsroots/team3] LockDir=/locks/team3 [/cvsroots/team4] LockDir=/locks/team4 [/cvsroots/team3] [/cvsroots/team4] # Override logged commands for teams 3 & 4. LogHistory=all
This example file sets up separate lock directories for each project, as well as a default set of logged commands overridden for the example’s team 3 & team 4. This syntax could be useful, for instance, if you wished to share a single config file, for instance /etc/cvs.conf, among several repositories.
Currently defined keywords are:
HistorySearchPath=pattern ¶Request that CVS look for its history information in files matching pattern, which is a standard UNIX file glob. If pattern matches multiple files, all will be searched in lexicographically sorted order. See history—Show repository access history, and The history file, for more.
If no value is supplied for this option, it defaults to $CVSROOT/CVSROOT/history.
HistoryLogPath=path ¶Control where CVS logs its history. If the file does not exist, CVS
will attempt to create it. Format strings, as available to the GNU C
strftime function and often the UNIX date command, and the string
$CVSROOT will be substituted in this path. For example, consider the
line:
HistoryLogPath=$CVSROOT/CVSROOT/history/%Y-%m-%d
This line would cause CVS to attempt to create its history file in a subdirectory (history) of the configuration directory (CVSROOT) with a name equal to the current date representation in the ISO8601 format (for example, on May 11, 2005, CVS would attempt to log its history under the repository root directory in a file named CVSROOT/history/2005-05-11). See history—Show repository access history, and The history file, for more.
If no value is supplied for this option, it defaults to $CVSROOT/CVSROOT/history.
ImportNewFilesToVendorBranchOnly=value ¶Specify whether cvs import should always behave as if the
‘-X’ flag was specified on the command line.
value may be either ‘yes’ or ‘no’. If set to ‘yes’,
all uses of cvs import on the repository will behave as if the
‘-X’ flag was set. The default value is ‘no’.
KeywordExpand=value ¶Specify ‘i’ followed by a list of keywords to be expanded (for example, ‘KeywordExpand=iMYCVS,Name,Date,Mdocdate’), or ‘e’ followed by a list of keywords not to be expanded (for example, ‘KeywordExpand=eCVSHeader’). For more on keyword expansion, see Configuring Keyword Expansion.
LocalKeyword=value ¶Specify a local alias for a standard keyword. See Keyword substitution for more information in local keywords. Example: ‘LocalKeyword=MYCVS=CVSHeader’
LockDir=directory ¶Put CVS lock files in directory rather than directly in the repository. This is useful if you want to let users read from the repository while giving them write access only to directory, not to the repository. It can also be used to put the locks on a very fast in-memory filesystem to speed up locking and unlocking the repository. You need to create directory, but CVS will create subdirectories of directory as it needs them. For information on CVS locks, see Several developers simultaneously attempting to run CVS.
Before enabling the LockDir option, make sure that you have tracked down and removed any copies of CVS 1.9 or older. Such versions neither support LockDir, nor will give an error indicating that they don’t support it. The result, if this is allowed to happen, is that some CVS users will put the locks one place, and others will put them another place, and therefore the repository could become corrupted. CVS 1.10 does not support LockDir but it will print a warning if run on a repository with LockDir enabled.
LogHistory=value ¶Control what is logged to the CVSROOT/history file (see history—Show repository access history).
Default of ‘TOEFWUPCGMAR’ (or simply ‘all’) will log
all transactions. Any subset of the default is
legal. (For example, to only log transactions that modify the
*,v files, use ‘LogHistory=TMAR’ which is nowadays
set by cvs init by default.)
To disable history logging
completely, use ‘LogHistory=’.
MaxCommentLeaderLength=length ¶Set to some length, in bytes, where a trailing ‘k’, ‘M’, ‘G’,
or ‘T’ causes the preceding nubmer to be interpreted as kilobytes,
megabytes, gigabytes, or terrabytes, respectively, will cause
$Log$ keywords (see Keyword substitution), with
more than length bytes preceding it on a line to be ignored (or to fall
back on the comment leader set in the RCS archive file - see
UseArchiveCommentLeader below). Defaults to 20 bytes to allow checkouts
to proceed normally when they include binary files containing
$Log$ keywords and which users have neglected to mark
as binary.
MinCompressionLevel=value ¶MaxCompressionLevel=valueRestricts the level of compression used by the CVS server to a value between 0 and 9. values 1 through 9 are the same ZLIB compression levels accepted by the ‘-z’ option (see Global options), and 0 means no compression. When one or both of these keys are set and a client requests a level outside the specified range, the server will simply use the closest permissable level. Clients will continue compressing at the level requested by the user.
The exception is when level 0 (no compression) is not available and the client fails to request any compression. The CVS server will then exit with an error message when it becomes apparent that the client is not going to request compression. This will not happen with clients version 1.12.13 and later since these client versions allow the server to notify them that they must request some level of compression.
PrimaryServer=CVSROOT ¶When specified, and the repository specified by CVSROOT is not the one
currently being accessed, then the server will turn itself into a transparent
proxy to CVSROOT for write requests. The hostname configured as
part of CVSROOT must resolve to the same string returned by the
uname command on the primary server for this to work. Host name
resolution is performed via some combination of named, a broken out
line from /etc/hosts, and the Network Information Service (NIS or YP),
depending on the configuration of the particular system.
Only the ‘:ext:’ method is currently supported for primaries (actually, ‘:fork:’ is supported as well, but only for testing - if you find another use for accessing a primary via the ‘:fork:’ method, please send a note to bug-cvs@nongnu.org about it). See Distributing load across several CVS servers for more on configuring and using write proxies.
RCSBIN=bindir ¶For CVS 1.9.12 through 1.9.18, this setting told CVS to look for RCS programs in the bindir directory. Current versions of CVS do not run RCS programs; for compatibility this setting is accepted, but it does nothing.
RereadLogAfterVerify=value ¶Modify the ‘commit’ command such that CVS will reread the log message after running the program specified by verifymsg. value may be one of ‘yes’ or ‘always’, indicating that the log message should always be reread; ‘no’ or ‘never’, indicating that it should never be reread; or value may be ‘stat’, indicating that the file should be checked with the filesystem ‘stat()’ function to see if it has changed (see warning below) before rereading. The default value is ‘always’.
Note: the ‘stat’ mode can cause CVS to pause for up to one extra second per directory committed. This can be less IO and CPU intensive but is not recommended for use with large repositories
See Verifying log messages, for more information on how verifymsg may be used.
SystemAuth=value ¶If value is ‘yes’, then pserver should check for users in the system’s user database if not found in CVSROOT/passwd. If it is ‘no’, then all pserver users must exist in CVSROOT/passwd. The default is ‘yes’. For more on pserver, see Direct connection with password authentication.
TmpDir=path ¶Specify path as the directory to create temporary files in. See Global options, for more on setting the path to the temporary directory. This option first appeared with CVS release 1.12.13.
TopLevelAdmin=value ¶Modify the ‘checkout’ command to create a ‘CVS’ directory at the top level of the new working directory, in addition to ‘CVS’ directories created within checked-out directories. The default value is ‘no’.
This option is useful if you find yourself performing
many commands at the top level of your working
directory, rather than in one of the checked out
subdirectories. The CVS directory created there
will mean you don’t have to specify CVSROOT for
each command. It also provides a place for the
CVS/Template file (see How data is stored in the working directory).
UseArchiveCommentLeader=value ¶Set to true, if the text preceding a $Log$
keyword is found to exceed MaxCommentLeaderLength (above) bytes, then
the comment leader set in the RCS archive file (see admin—Administration front-end for RCS), if any, will
be used instead. If there is no comment leader set in the archive file or
value is set to ‘false’, then the keyword will not be expanded
(see Keyword List). To force the comment leader in the RCS archive file to
be used exclusively (and $Log$ expansion skipped in
files where the comment leader has not been set in the archive file), set
value and set MaxCommentLeaderLength to 0.
UseNewInfoFmtStrings=value ¶Specify whether CVS should support the new or old command line template model for the commit support files (see The commit support files). This configuration variable began life in deprecation and is only here in order to give people time to update legacy repositories to use the new format string syntax before support for the old syntax is removed. For information on updating your repository to support the new model, please see Updating legacy repositories to stop using deprecated command line template formats.
Note that new repositories (created with the cvs init command)
will have this value set to ‘yes’, but the default value is ‘no’.
UserAdminOptions=value ¶Control what options will be allowed with the cvs admin
command (see admin—Administration front-end for RCS) for users not in the cvsadmin group.
The value string is a list of single character options
which should be allowed. If a user who is not a member of the
cvsadmin group tries to execute any cvs admin
option which is not listed they will will receive an error message
reporting that the option is restricted.
If no cvsadmin group exists on the server, CVS will
ignore the UserAdminOptions keyword (see admin—Administration front-end for RCS).
When not specified, UserAdminOptions defaults to
‘k’. In other words, it defaults to allowing
users outside of the cvsadmin group to use the
cvs admin command only to change the default keyword
expansion mode for files.
As an example, to restrict users not in the cvsadmin
group to using cvs admin to change the default keyword
substitution mode, lock revisions, unlock revisions, and
replace the log message, use ‘UserAdminOptions=klum’.
This is a complete list of all environment variables that affect CVS (Windows users, please bear with this list; $VAR is equivalent to %VAR% at the Windows command prompt).
$CVSIGNORE ¶A whitespace-separated list of file name patterns that CVS should ignore. See Ignoring files via cvsignore.
$CVSWRAPPERS ¶A whitespace-separated list of file name patterns that CVS should treat as wrappers. See The cvswrappers file.
$CVSREAD ¶If this is set, checkout and update will
try hard to make the files in your working directory
read-only. When this is not set, the default behavior
is to permit modification of your working files.
$CVSREADONLYFS ¶Turns on read-only repository mode. This allows one to check out from a read-only repository, such as within an anoncvs server, or from a CD-ROM repository.
Setting this has the same effect as if the ‘-R’ command-line option is used. This can also allow the use of read-only NFS repositories.
$CVSUMASKControls permissions of files in the repository. See File permissions.
$CVSROOTShould contain the full pathname to the root of the CVS
source repository (where the RCS files are
kept). This information must be available to CVS for
most commands to execute; if $CVSROOT is not set,
or if you wish to override it for one invocation, you
can supply it on the command line: ‘cvs -d cvsroot
cvs_command…’ Once you have checked out a working
directory, CVS stores the appropriate root (in
the file CVS/Root), so normally you only need to
worry about this when initially checking out a working
directory.
$CVSEDITOR ¶$EDITOR$VISUALSpecifies the program to use for recording log messages
during commit. $CVSEDITOR overrides
$EDITOR, which overrides $VISUAL.
See Committing your changes for more or
Global options for alternative ways of specifying a
log editor.
$PATH ¶If $RCSBIN is not set, and no path is compiled
into CVS, it will use $PATH to try to find all
programs it uses.
$HOME ¶$HOMEPATH ¶$HOMEDRIVEUsed to locate the directory where the .cvsrc
file, and other such files, are searched. On Unix, CVS
just checks for HOME. On Windows NT, the system will
set HOMEDRIVE, for example to ‘d:’ and HOMEPATH,
for example to \joe. On Windows 95, you’ll
probably need to set HOMEDRIVE and HOMEPATH yourself.
$CVS_RSH ¶Specifies the external program which CVS connects with,
when :ext: access method is specified.
see Connecting with rsh.
$CVS_SERVERUsed in client-server mode when accessing a remote
repository using RSH. It specifies the name of
the program to start on the server side (and any
necessary arguments) when accessing a remote repository
using the :ext:, :fork:, or :server: access methods.
The default value for :ext: and :server: is cvs;
the default value for :fork: is the name used to run the client.
see Connecting with rsh
$CVS_PASSFILEUsed in client-server mode when accessing the cvs
login server. Default value is $HOME/.cvspass.
see Using the client with password authentication
$CVS_CLIENT_PORT ¶Used in client-server mode to set the port to use when accessing the server via Kerberos, GSSAPI, or CVS’s password authentication protocol if the port is not specified in the CVSROOT. see Remote repositories
$CVS_PROXY_PORT ¶Used in client-server mode to set the port to use when accessing a server via a web proxy, if the port is not specified in the CVSROOT. Works with GSSAPI, and the password authentication protocol. see Remote repositories
$CVS_RCMD_PORT ¶Used in client-server mode. If set, specifies the port number to be used when accessing the RCMD demon on the server side. (Currently not used for Unix clients).
$CVS_CLIENT_LOG ¶Used for debugging only in client-server mode.
If set and not empty, everything sent to the server is logged
into $CVS_CLIENT_LOG.in, and everything received
from the server is logged into $CVS_CLIENT_LOG.out.
$CVS_SECONDARY_LOG ¶Used for debugging only in secondary write proxy mode.
If set and not empty, everything sent to the primary server is logged
into $CVS_SECONDARY_LOG.in, and everything received
from the primary server is logged into $CVS_SECONDARY_LOG.out.
$CVS_SERVER_LOG ¶Used for debugging only in client-server mode.
If set and not empty, everything sent to the client is logged
into $CVS_SERVER_LOG.in, and everything received
from the client is logged into $CVS_SERVER_LOG.out.
$CVS_SERVER_SLEEP ¶Used only for debugging the server side in client-server mode. If set, delays the start of the server child process the specified amount of seconds so that you can attach to it with a debugger.
$CVS_IGNORE_REMOTE_ROOT ¶For CVS 1.10 and older, setting this variable
prevents CVS from overwriting the CVS/Root
file when the ‘-d’ global option is specified.
Later versions of CVS do not rewrite
CVS/Root, so CVS_IGNORE_REMOTE_ROOT has no
effect.
$CVS_LOCAL_BRANCH_NUM ¶Setting this variable allows some control over the
branch number that is assigned. This is specifically to
support the local commit feature of CVSup. If one sets
CVS_LOCAL_BRANCH_NUM to (say) 1000 then branches
the local repository, the revision numbers will look
like 1.66.1000.xx. There is almost a dead-set certainty
that there will be no conflicts with version numbers.
$COMSPEC ¶Used under OS/2 only. It specifies the name of the command interpreter and defaults to CMD.EXE.
$TMPDIR ¶Directory in which temporary files are located. See Global options, for more on setting the temporary directory.
$CVS_PID ¶This is the process identification (aka pid) number of the CVS process. It is often useful in the programs and/or scripts specified by the commitinfo, verifymsg, loginfo files.
The repository format is compatible going back to CVS 1.3. But see Using watches with old versions of CVS, if you have copies of CVS 1.6 or older and you want to use the optional developer communication features.
The working directory format is compatible going back to CVS 1.5. It did change between CVS 1.3 and CVS 1.5. If you run CVS 1.5 or newer on a working directory checked out with CVS 1.3, CVS will convert it, but to go back to CVS 1.3 you need to check out a new working directory with CVS 1.3.
The remote protocol is interoperable going back to CVS 1.5, but no further (1.5 was the first official release with the remote protocol, but some older versions might still be floating around). In many cases you need to upgrade both the client and the server to take advantage of new features and bug fixes, however.
If you are having trouble with CVS, this appendix may help. If there is a particular error message which you are seeing, then you can look up the message alphabetically. If not, you can look through the section on other problems to see if your problem is mentioned there.
Here is a partial list of error messages that you may see from CVS. It is not a complete list—CVS is capable of printing many, many error messages, often with parts of them supplied by the operating system, but the intention is to list the common and/or potentially confusing error messages.
The messages are alphabetical, but introductory text such as ‘cvs update: ’ is not considered in ordering them.
In some cases the list includes messages printed by old versions of CVS (partly because users may not be sure which version of CVS they are using at any particular moment).
file:line: Assertion 'text' failedThe exact format of this message may vary depending on your system. It indicates a bug in CVS, which can be handled as described in Dealing with bugs in CVS or this manual.
cvs command: authorization failed: server host rejected accessThis is a generic response when trying to connect to a
pserver server which chooses not to provide a
specific reason for denying authorization. Check that
the username and password specified are correct and
that the CVSROOT specified is allowed by ‘--allow-root’
or ‘--allow-root-regexp’
in inetd.conf. See Direct connection with password authentication.
cvs command: conflict: removed file was modified by second partyThis message indicates that you removed a file, and someone else modified it. To resolve the conflict, first run ‘cvs add file’. If desired, look at the other party’s modification to decide whether you still want to remove it. If you don’t want to remove it, stop here. If you do want to remove it, proceed with ‘cvs remove file’ and commit your removal.
cannot change permissions on temporary directoryOperation not permitted
This message has been happening in a non-reproducible,
occasional way when we run the client/server testsuite,
both on Red Hat Linux 3.0.3 and 4.1. We haven’t been
able to figure out what causes it, nor is it known
whether it is specific to Linux (or even to this
particular machine!). If the problem does occur on
other unices, ‘Operation not permitted’ would be
likely to read ‘Not owner’ or whatever the system
in question uses for the unix EPERM error. If
you have any information to add, please let us know as
described in Dealing with bugs in CVS or this manual. If you experience this error
while using CVS, retrying the operation which
produced it should work fine.
cvs [server aborted]: Cannot check out files into the repository itselfThe obvious cause for this message (especially for
non-client/server CVS) is that the CVS root
is, for example, /usr/local/cvsroot and you try
to check out files when you are in a subdirectory, such
as /usr/local/cvsroot/test. However, there is a
more subtle cause, which is that the temporary
directory on the server is set to a subdirectory of the
root (which is also not allowed). If this is the
problem, set the temporary directory to somewhere else,
for example /var/tmp; see TMPDIR in
All environment variables which affect CVS, for how to set the
temporary directory.
cannot commit files as 'root'See ‘'root' is not allowed to commit files’.
cannot open CVS/Entries for reading: No such file or directoryThis generally indicates a CVS internal error, and can be handled as with other CVS bugs (see Dealing with bugs in CVS or this manual). Usually there is a workaround—the exact nature of which would depend on the situation but which hopefully could be figured out.
cvs [init aborted]: cannot open CVS/Root: No such file or directoryThis message is harmless. Provided it is not accompanied by other errors, the operation has completed successfully. This message should not occur with current versions of CVS, but it is documented here for the benefit of CVS 1.9 and older.
cvs server: cannot open /root/.cvsignore: Permission deniedcvs [server aborted]: can't chdir(/root): Permission deniedcvs [checkout aborted]: cannot rename file file to CVS/,,file: Invalid argumentThis message has been reported as intermittently happening with CVS 1.9 on Solaris 2.5. The cause is unknown; if you know more about what causes it, let us know as described in Dealing with bugs in CVS or this manual.
cvs [command aborted]: cannot start server via rcmdThis, unfortunately, is a rather nonspecific error
message which CVS 1.9 will print if you are
running the CVS client and it is having trouble
connecting to the server. Current versions of CVS
should print a much more specific error message. If
you get this message when you didn’t mean to run the
client at all, you probably forgot to specify
:local:, as described in The Repository.
ci: file,v: bad diff output line: Binary files - and /tmp/T2a22651 differCVS 1.9 and older will print this message when trying to check in a binary file if RCS is not correctly installed. Re-read the instructions that came with your RCS distribution and the INSTALL file in the CVS distribution. Alternately, upgrade to a current version of CVS, which checks in files itself rather than via RCS.
cvs checkout: could not check out fileWith CVS 1.9, this can mean that the co program
(part of RCS) returned a failure. It should be
preceded by another error message, however it has been
observed without another error message and the cause is
not well-understood. With the current version of CVS,
which does not run co, if this message occurs
without another error message, it is definitely a CVS
bug (see Dealing with bugs in CVS or this manual).
cvs [login aborted]: could not find out home directoryThis means that you need to set the environment
variables that CVS uses to locate your home directory.
See the discussion of HOME, HOMEDRIVE, and HOMEPATH in
All environment variables which affect CVS.
cvs update: could not merge revision rev of file: No such file or directoryCVS 1.9 and older will print this message if there was
a problem finding the rcsmerge program. Make
sure that it is in your PATH, or upgrade to a
current version of CVS, which does not require
an external rcsmerge program.
cvs [update aborted]: could not patch file: No such file or directoryThis means that there was a problem finding the
patch program. Make sure that it is in your
PATH. Note that despite appearances the message
is not referring to whether it can find file.
If both the client and the server are running a current
version of CVS, then there is no need for an
external patch program and you should not see this
message. But if either client or server is running
CVS 1.9, then you need patch.
cvs update: could not patch file; will refetchThis means that for whatever reason the client was unable to apply a patch that the server sent. The message is nothing to be concerned about, because inability to apply the patch only slows things down and has no effect on what CVS does.
dying gasps from server unexpectedThere is a known bug in the server for CVS 1.9.18 and older which can cause this. For me, this was reproducible if I used the ‘-t’ global option. It was fixed by Andy Piper’s 14 Nov 1997 change to src/filesubr.c, if anyone is curious. If you see the message, you probably can just retry the operation which failed, or if you have discovered information concerning its cause, please let us know as described in Dealing with bugs in CVS or this manual.
end of file from server (consult above messages if any)The most common cause for this message is if you are
using an external rsh program and it exited with
an error. In this case the rsh program should
have printed a message, which will appear before the
above message. For more information on setting up a
CVS client and server, see Remote repositories.
cvs [update aborted]: EOF in key in RCS file file,vcvs [checkout aborted]: EOF while looking for end of string in RCS file file,vThis means that there is a syntax error in the given RCS file. Note that this might be true even if RCS can read the file OK; CVS does more error checking of errors in the RCS file. That is why you may see this message when upgrading from CVS 1.9 to CVS 1.10. The likely cause for the original corruption is hardware, the operating system, or the like. Of course, if you find a case in which CVS seems to corrupting the file, by all means report it, (see Dealing with bugs in CVS or this manual). There are quite a few variations of this error message, depending on exactly where in the RCS file CVS finds the syntax error.
cvs commit: Executing 'mkmodules' ¶This means that your repository is set up for a version of CVS prior to CVS 1.8. When using CVS 1.8 or later, the above message will be preceded by
cvs commit: Rebuilding administrative file database
If you see both messages, the database is being rebuilt
twice, which is unnecessary but harmless. If you wish
to avoid the duplication, and you have no versions of
CVS 1.7 or earlier in use, remove -i mkmodules
every place it appears in your modules
file. For more information on the modules file,
see The modules file.
missing authorTypically this can happen if you created an RCS file with your username set to empty. CVS will, bogusly, create an illegal RCS file with no value for the author field. The solution is to make sure your username is set to a non-empty value and re-create the RCS file.
cvs [checkout aborted]: no such tag tagThis message means that CVS isn’t familiar with the tag tag. Usually the root cause is that you have mistyped a tag name. Ocassionally this can also occur because the users creating tags do not have permissions to write to the CVSROOT/val-tags file (see File permissions, for more).
Prior to CVS version 1.12.10, there were a few relatively obscure cases where a given tag could be created in an archive file in the repository but CVS would require the user to try a few other CVS commands involving that tag until one was found whch caused CVS to update the val-tags file, at which point the originally failing command would begin to work. This same method can be used to repair a val-tags file that becomes out of date due to the permissions problem mentioned above. This updating is only required once per tag - once a tag is listed in val-tags, it stays there.
Note that using ‘tag -f’ to not require tag matches did not and does not override this check (see Common command options).
*PANIC* administration files missingThis typically means that there is a directory named CVS but it does not contain the administrative files which CVS puts in a CVS directory. If the problem is that you created a CVS directory via some mechanism other than CVS, then the answer is simple, use a name other than CVS. If not, it indicates a CVS bug (see Dealing with bugs in CVS or this manual).
rcs error: Unknown option: -x,v/This message will be followed by a usage message for RCS. It means that you have an old version of RCS (probably supplied with your operating system), as well as an old version of CVS. CVS 1.9.18 and earlier only work with RCS version 5 and later; current versions of CVS do not run RCS programs.
cvs [server aborted]: received broken pipe signalThis message can be caused by a loginfo program that fails to read all of the log information from its standard input. If you find it happening in any other circumstances, please let us know as described in Dealing with bugs in CVS or this manual.
'root' is not allowed to commit filesWhen committing a permanent change, CVS makes a log entry of
who committed the change. If you are committing the change logged
in as "root" (not under "su" or other root-priv giving program),
CVS cannot determine who is actually making the change.
As such, by default, CVS disallows changes to be committed by users
logged in as "root". (You can disable this option by passing the
--enable-rootcommit option to configure and recompiling CVS.
On some systems this means editing the appropriate config.h file
before building CVS.)
cvs [server aborted]: Secondary out of sync with primary!This usually means that the version of CVS running on a secondary server is incompatible with the version running on the primary server (see Distributing load across several CVS servers). This will not occur if the client supports redirection.
It is not the version number that is significant here, but the list of supported requests that the servers provide to the client. For example, even if both servers were the same version, if the secondary was compiled with GSSAPI support and the primary was not, the list of supported requests provided by the two servers would be different and the secondary would not work as a transparent proxy to the primary. Conversely, even if the two servers were radically different versions but both provided the same list of valid requests to the client, the transparent proxy would succeed.
Terminated with fatal signal 11This message usually indicates that CVS (the server, if you’re using client/server mode) has run out of (virtual) memory. Although CVS tries to catch the error and issue a more meaningful message, there are many circumstances where that is not possible. If you appear to have lots of memory available to the system, the problem is most likely that you’re running into a system-wide limit on the amount of memory a single process can use or a similar process-specific limit. The mechanisms for displaying and setting such limits vary from system to system, so you’ll have to consult an expert for your particular system if you don’t know how to do that.
Too many arguments!This message is typically printed by the log.pl script which is in the contrib directory in the CVS source distribution. In some versions of CVS, log.pl has been part of the default CVS installation. The log.pl script gets called from the loginfo administrative file. Check that the arguments passed in loginfo match what your version of log.pl expects. In particular, the log.pl from CVS 1.3 and older expects the log file as an argument whereas the log.pl from CVS 1.5 and newer expects the log file to be specified with a ‘-f’ option. Of course, if you don’t need log.pl you can just comment it out of loginfo.
cvs [update aborted]: unexpected EOF reading file,vSee ‘EOF in key in RCS file’.
cvs [login aborted]: unrecognized auth response from serverThis message typically means that the server is not set up properly. For example, if inetd.conf points to a nonexistent cvs executable. To debug it further, find the log file which inetd writes (/var/log/messages or whatever inetd uses on your system). For details, see Trouble making a connection to a CVS server, and Setting up the server for password authentication.
cvs commit: Up-to-date check failed for `file'This means that someone else has committed a change to
that file since the last time that you did a cvs
update. So before proceeding with your cvs
commit you need to cvs update. CVS will merge
the changes that you made and the changes that the
other person made. If it does not detect any conflicts
it will report ‘M file’ and you are ready
to cvs commit. If it detects conflicts it will
print a message saying so, will report ‘C file’,
and you need to manually resolve the
conflict. For more details on this process see
Conflicts example.
Usage: diff3 [-exEX3 [-i | -m] [-L label1 -L label3]] file1 file2 file3Only one of [exEX3] allowed
This indicates a problem with the installation of
diff3 and rcsmerge. Specifically
rcsmerge was compiled to look for GNU diff3, but
it is finding unix diff3 instead. The exact text of
the message will vary depending on the system. The
simplest solution is to upgrade to a current version of
CVS, which does not rely on external
rcsmerge or diff3 programs.
warning: unrecognized response `text' from cvs serverIf text contains a valid response (such as ‘ok’) followed by an extra carriage return character (on many systems this will cause the second part of the message to overwrite the first part), then it probably means that you are using the ‘:ext:’ access method with a version of rsh, such as most non-unix rsh versions, which does not by default provide a transparent data stream. In such cases you probably want to try ‘:server:’ instead of ‘:ext:’. If text is something else, this may signify a problem with your CVS server. Double-check your installation against the instructions for setting up the CVS server.
cvs commit: [time] waiting for user's lock in directoryThis is a normal message, not an error. See Several developers simultaneously attempting to run CVS, for more details.
cvs commit: warning: editor session failed ¶This means that the editor which CVS is using exits with a nonzero
exit status. Some versions of vi will do this even when there was not
a problem editing the file. If so, point the
CVSEDITOR environment variable to a small script
such as:
#!/bin/sh vi $* exit 0
cvs update: warning: file was lostThis means that the working copy of file has been deleted
but it has not been removed from CVS.
This is nothing to be concerned about,
the update will just recreate the local file from the repository.
(This is a convenient way to discard local changes to a file:
just delete it and then run cvs update.)
cvs update: warning: file is not (any longer) pertinentThis means that the working copy of file has been deleted, it has not been removed from CVS in the current working directory, but it has been removed from CVS in some other working directory. This is nothing to be concerned about, the update would have removed the local file anyway.
This section concerns what to do if you are having trouble making a connection to a CVS server. If you are running the CVS command line client running on Windows, first upgrade the client to CVS 1.9.12 or later. The error reporting in earlier versions provided much less information about what the problem was. If the client is non-Windows, CVS 1.9 should be fine.
If the error messages are not sufficient to track down the problem, the next steps depend largely on which access method you are using.
:ext: ¶Try running the rsh program from the command line. For example: "rsh servername cvs -v" should print CVS version information. If this doesn’t work, you need to fix it before you can worry about CVS problems.
:server: ¶You don’t need a command line rsh program to use this access method, but if you have an rsh program around, it may be useful as a debugging tool. Follow the directions given for :ext:.
:pserver: ¶Errors along the lines of "connection refused" typically indicate that inetd isn’t even listening for connections on port 2401 whereas errors like "connection reset by peer", "received broken pipe signal", "recv() from server: EOF", or "end of file from server" typically indicate that inetd is listening for connections but is unable to start CVS (this is frequently caused by having an incorrect path in inetd.conf or by firewall software rejecting the connection). "unrecognized auth response" errors are caused by a bad command line in inetd.conf, typically an invalid option or forgetting to put the ‘pserver’ command at the end of the line. Another less common problem is invisible control characters that your editor "helpfully" added without you noticing.
One good debugging tool is to "telnet servername 2401". After connecting, send any text (for example "foo" followed by return). If CVS is working correctly, it will respond with
cvs [pserver aborted]: bad auth protocol start: foo
If instead you get:
Usage: cvs [cvs-options] command [command-options-and-arguments] ...
then you’re missing the ‘pserver’ command at the end of the line in inetd.conf; check to make sure that the entire command is on one line and that it’s complete.
Likewise, if you get something like:
Unknown command: `pserved'
CVS commands are:
add Add a new file/directory to the repository
...
then you’ve misspelled ‘pserver’ in some way. If it isn’t obvious, check for invisible control characters (particularly carriage returns) in inetd.conf.
If it fails to work at all, then make sure inetd is working right. Change the invocation in inetd.conf to run the echo program instead of cvs. For example:
2401 stream tcp nowait root /bin/echo echo hello
After making that change and instructing inetd to re-read its configuration file, "telnet servername 2401" should show you the text hello and then the server should close the connection. If this doesn’t work, you need to fix it before you can worry about CVS problems.
On AIX systems, the system will often have its own program trying to use port 2401. This is AIX’s problem in the sense that port 2401 is registered for use with CVS. I hear that there is an AIX patch available to address this problem.
Another good debugging tool is the ‘-d’ (debugging) option to inetd. Consult your system documentation for more information.
If you seem to be connecting but get errors like:
cvs server: cannot open /root/.cvsignore: Permission denied cvs [server aborted]: can't chdir(/root): Permission denied
then you probably haven’t specified ‘-f’ in inetd.conf.
(In releases prior to CVS 1.11.1, this problem can be caused by
your system setting the $HOME environment variable
for programs being run by inetd. In this case, you can either
have inetd run a shell script that unsets $HOME and then runs
CVS, or you can use env to run CVS with a pristine
environment.)
If you can connect successfully for a while but then can’t, you’ve probably hit inetd’s rate limit. (If inetd receives too many requests for the same service in a short period of time, it assumes that something is wrong and temporarily disables the service.) Check your inetd documentation to find out how to adjust the rate limit (some versions of inetd have a single rate limit, others allow you to set the limit for each service separately.)
Here is a list of problems which do not fit into the above categories. They are in no particular order.
HOMEDRIVE and HOMEPATH in
All environment variables which affect CVS). CVS expects the home
directory to not end in a slash, for example C:
or C:\cvs.
cvs update finds a conflict and tries to
merge, as described in Conflicts example, but
doesn’t tell you there were conflicts, then you may
have an old version of RCS. The easiest solution
probably is to upgrade to a current version of
CVS, which does not rely on external RCS
programs.
Roland Pesch, then of Cygnus Support <roland@wrs.com>
wrote the manual pages which were distributed with
CVS 1.3. Much of their text was copied into this
manual. He also read an early draft
of this manual and contributed many ideas and
corrections.
The mailing-list info-cvs is sometimes
informative. I have included information from postings
made by the following persons:
David G. Grubbs <dgg@think.com>.
Some text has been extracted from the man pages for RCS.
The CVS FAQ by David G. Grubbs has provided useful material. The FAQ is no longer maintained, however, and this manual is about the closest thing there is to a successor (with respect to documenting how to use CVS, at least).
In addition, the following persons have helped by telling me about mistakes I’ve made:
Roxanne Brunskill <rbrunski@datap.ca>, Kathy Dyer <dyer@phoenix.ocf.llnl.gov>, Karl Pingle <pingle@acuson.com>, Thomas A Peterson <tap@src.honeywell.com>, Inge Wallin <ingwa@signum.se>, Dirk Koschuetzki <koschuet@fmi.uni-passau.de> and Michael Brown <brown@wi.extrel.com>.
The list of contributors here is not comprehensive; for a more complete list of who has contributed to this manual see the file doc/ChangeLog in the CVS source distribution.
MirBSD is the de-facto (if not de-iure yet) new upstream of GNU CVS since 2012 or so; this version is provided in Debian as well. Responsible is:
mirabilos <m@mirbsd.org>
CVS Homepage: http://www.nongnu.org/cvs/
Neither CVS nor this manual is perfect, and they probably never will be. If you are having trouble using CVS, or think you have found a bug, there are a number of things you can do about it. Note that if the manual is unclear, that can be considered a bug in the manual, so these problems are often worth doing something about as well as problems with CVS itself.
Ximbiot 319 S. River St. Harrisburg, PA 17104-1657 USA Email: info@ximbiot.com Phone: (717) 579-6168 Fax: (717) 234-3125 http://ximbiot.com/
If you are so inspired, increasing the information available on the net is likely to be appreciated. For example, before the standard CVS distribution worked on Windows 95, there was a web page with some explanation and patches for running CVS on Windows 95, and various people helped out by mentioning this page on mailing lists or newsgroups when the subject came up.
People often ask if there is a list of known bugs or whether a particular bug is a known one. The file BUGS in the CVS source distribution is one list of known bugs, but it doesn’t necessarily try to be comprehensive. Perhaps there will never be a comprehensive, detailed list of known bugs.
| Jump to: | _
-
!
.
/
&
#
<
=
>
A B C D E F G H I J K L M N O P R S T U V W X Z |
|---|
| Jump to: | _
-
!
.
/
&
#
<
=
>
A B C D E F G H I J K L M N O P R S T U V W X Z |
|---|