title: Passing variable number of arguments around
body: <p>Say I have a C function which takes a variable number of arguments: How can I call another function which expects a variable number of arguments from inside of it, passing all the arguments that got into the first function?</p>
  
  <p>Example:</p>
  
  <pre><code>void format_string(char *fmt, ...);
  
  void debug_print(int dbg_lvl, char *fmt, ...) {
      format_string(fmt, /* how do I pass all the arguments from '...'? */);
      fprintf(stdout, fmt);
   }
  </code></pre>