Function my_vfprintf

strings/my_vsnprintf.c:824–866

*/

int my_vfprintf(FILE *stream, const char* format, va_list args)
{
  char cvtbuf[1024];
  int alloc= 0;
  char *p= cvtbuf;
  size_t cur_len= sizeof(cvtbuf), actual;
  int ret;

  /*
    We do not know how much buffer we need.
    So start with a reasonably-sized stack-allocated buffer, and increase
    it exponentially until it is big enough.
  */
  for (;;)
  {
    size_t new_len;
    actual= my_vsnprintf(p, cur_len, format, args);
    if (actual < cur_len - 1)
      break;
    /*
      Not enough space (or just enough with nothing to spare - but we cannot
      distinguish this case from the return value). Allocate a bigger buffer
      and try again.
    */
    if (alloc)
      my_free(p);
    else
      alloc= 1;
    new_len= cur_len*2;
    if (new_len < cur_len)
      return 0;                                 /* Overflow */
    cur_len= new_len;
    p= my_malloc(PSI_INSTRUMENT_ME, cur_len, MYF(MY_FAE));
    if (!p)
      return 0;
  }
  ret= (int) actual;
  if (fputs(p, stream) < 0)
    ret= -1;
  if (alloc)
    my_free(p);
  return ret;
}

int my_fprintf(FILE *stream, const char* format, ...)
{