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

/* #define OLD_NAMES */

#ifdef OLD_NAMES /* Define this on Solaris */
#define FIRST_NAME "US/Eastern"
#define SECOND_NAME "US/Pacific"
#else /* Proper Olson tzdata names. */
#define FIRST_NAME "America/New_York"
#define SECOND_NAME "America/Los_Angeles"
#endif

int main()
{
  struct tm* test_tm;
  time_t then = 988989060;
  char buf[256];

  /* Compatibility names are used, rather than new Olson names, so as to
   * test on Solaris. */
  if (putenv("TZ=" FIRST_NAME) != 0) {
    fprintf(stderr, "putenv failed (1)\n");
    exit(1);
  }

  if ((test_tm = localtime(&then)) == NULL) {
    fprintf(stderr, "localtime failed\n");
    exit(1);
  }

  if (strftime(buf, sizeof(buf), "%a %d %h %H:%M:%S %Y %Z", test_tm) == 0) {
    fprintf(stderr, "strftime failed (1)\n");
    exit(1);
  }

  printf("%s\n", buf);

  if (putenv("TZ=" SECOND_NAME) != 0) {
    fprintf(stderr, "putenv failed (2)\n");
    exit(1);
  }

  tzset();

  if (strftime(buf, sizeof(buf), "%a %d %h %H:%M:%S %Y %Z", test_tm) == 0) {
    fprintf(stderr, "strftime failed (2)\n");
    exit(1);
  }

  printf("%s\n", buf);

  test_tm->tm_isdst = -1;
  if (mktime(test_tm) == -1) {
    fprintf(stderr, "mktime failed\n");
    exit(1);
  }

  if (strftime(buf, sizeof(buf), "%a %d %h %H:%M:%S %Y %Z", test_tm) == 0) {
    fprintf(stderr, "strftime failed (3)\n");
    exit(1);
  }

  printf("%s\n", buf);

  exit(0);
}