How to Bypass a Standard C++ Function While Maintaining Its Functionality

Question

I am looking for a way to be able to redefine a set of POSIX functions but then end the redefinition with a call to the original function. The idea is that I am trying to create

Answer 1

Typical way of doing is on Unix is via LD_PRELOAD, example (Unix) below proxies a function call, malloc in particular (full example):

/**
 * malloc() direct call
 */
inline void * libc_malloc(size_t size)
{
  typedef void* (*malloc_func_t)(size_t);
  static malloc_func_t malloc_func = (malloc_func_t) dlsym(RTLD_NEXT, "malloc");

  return malloc_func(size);
}