Using LC_TIME with strftime

strftime.c

/*
 * The manualpage of strftime notes:
 *   "The environment variables TZ and LC_TIME are used." 
 *
 * What it does not say is that in order to get the locale
 * to actually work in your program is that 2 things are
 * needed in the code:
 * #include <locale.h>
 * and
 * setlocale(LC_TIME, "");
 *
 * The first thing includes the locale library, the second
 * line tells the program to use the locale that has been
 * set in the environment.
 *
 * Compile:
 * gcc -Wall strftime.c
 *
 * Running:
 * $ ./a.out 
 * day is "Thursday", month is "September"
 *
 * Running with locale set to Dutch
 * $ LC_TIME="nl_NL.utf8" ./a.out 
 * day is "donderdag", month is "september"
 *
 */

#include <time.h>
#include <stdio.h>
#include <stdlib.h>
#include <locale.h>

int main() {
  char outstr[200];
  time_t t;
  struct tm *tmp;

  /*
    Setting the locale 
  */
  setlocale(LC_TIME, "");

  t = time(NULL);
  tmp = localtime(&t);
  if ( tmp == NULL ) {
    perror("localtime");
    exit(EXIT_FAILURE);
  }
  if (strftime(outstr, sizeof(outstr), "day is \"%A\", month is \"%B\"", tmp) == 0) {
     fprintf(stderr, "strftime returned 0");
     exit(EXIT_FAILURE);
  }

  printf("%s\n", outstr);
  exit(EXIT_SUCCESS);
}