2.2 Simple Example

Here is a trivial example that calls puts a few times.

     #include <stdio.h>
     #include <ffi.h>
     
     int main()
     {
       ffi_cif cif;
       ffi_type *args[1];
       void *values[1];
       char *s;
       int rc;
     
       /* Initialize the argument info vectors */
       args[0] = &ffi_type_pointer;
       values[0] = &s;
     
       /* Initialize the cif */
       if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, 1,
     		       &ffi_type_uint, args) == FFI_OK)
         {
           s = "Hello World!";
           ffi_call(&cif, puts, &rc, values);
           /* rc now holds the result of the call to puts */
     
           /* values holds a pointer to the function's arg, so to
              call puts() again all we need to do is change the
              value of s */
           s = "This is cool!";
           ffi_call(&cif, puts, &rc, values);
         }
     
       return 0;
     }