#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <assert.h>

int main(int argc, char *argv[])
{
  const struct tm date = {
    .tm_sec = 0, .tm_min = 0, .tm_hour = 0, .tm_mday = 1, .tm_mon = 0,
    .tm_year = -1899, .tm_wday = 1, .tm_yday = 0, .tm_isdst = -1,
    .tm_gmtoff = 0, .tm_zone = 0x0
  };
  const char *fmt = "%E";
  const size_t maxsz = 65536u;

  size_t bufsz = 128;
  char *buf = NULL;

  // Mimic g_date_strftime (glib/gdate.c) approach
  do {
    buf = (char *)realloc(buf, bufsz);
    assert(buf);

    buf[0] = '\1'; // Mark to guess if empty or not enough space
    size_t len = strftime(buf, bufsz, fmt, &date);
    if (len != 0 || buf[0] == '\0')
      break;  // OK, done.

    bufsz *= 2;  // Assume more space needed
  } while (bufsz <= maxsz);  // .. up to a limit

  int rc;
  if (bufsz <= maxsz)
  {
    printf("Date: %s\n", buf);
    rc = EXIT_SUCCESS;
  }
  else
  {
    puts("Date: longest date ever :-\\");
    rc = EXIT_FAILURE;
  }
  free(buf);

  return rc;
}