A trivial example that creates a new puts
by binding
fputs
with stdout
.
#include <stdio.h> #include <ffi.h> /* Acts like puts with the file given at time of enclosure. */ void puts_binding(ffi_cif *cif, void *ret, void* args[], void *stream) { *(ffi_arg *)ret = fputs(*(char **)args[0], (FILE *)stream); } typedef int (*puts_t)(char *); int main() { ffi_cif cif; ffi_type *args[1]; ffi_closure *closure; void *bound_puts; int rc; /* Allocate closure and bound_puts */ closure = ffi_closure_alloc(sizeof(ffi_closure), &bound_puts); if (closure) { /* Initialize the argument info vectors */ args[0] = &ffi_type_pointer; /* Initialize the cif */ if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, 1, &ffi_type_sint, args) == FFI_OK) { /* Initialize the closure, setting stream to stdout */ if (ffi_prep_closure_loc(closure, &cif, puts_binding, stdout, bound_puts) == FFI_OK) { rc = ((puts_t)bound_puts)("Hello World!"); /* rc now holds the result of the call to fputs */ } } } /* Deallocate both closure, and bound_puts */ ffi_closure_free(closure); return 0; }