'memdup' function in C?

There is void *xmemdup (void const *p, size_t s) in GNU Gnulib's xalloc.h.

Note that it calls xalloc_die in case of insufficient memory.

You can implement it whith a simple function:

void* memdup(const void* mem, size_t size) { 
   void* out = malloc(size);

   if(out != NULL)
       memcpy(out, mem, size);

   return out;
}