Determine Original Exit Status Code

Question

In a software baseline I am maintaining, there are 150 statements spread out amongst various C applications that make a call to either another Linux command (e.g. rm -

Answer 1

How to write a wrapper

Following an example on how to apply a wrapper around the libc function system().

Create a new module (translation units) called system_wrapper.c like so:

The header system_wrapper.h:

#ifndef _SYSTEM_WRAPPER
#define _SYSTEM_WRAPPER

#define system(cmd) system_wrapper(cmd)

int system_wrapper(const char *);

#endif

The module system_wrapper.c:

#include  /* to prototype the original function, that is libc's system() */
#include "system_wrapper.h"

#undef system

int system_wrapper(const char * cmd)
{
  int result = system(cmd);

  /* Log result here. */

  return result;
}

Add this line to all modules using system():

#include "system_wrapper.h"