/*
 * Sample program for stime system call  - No.25
 *
 * stime - set time
 *
 * Synopsis
 *     #define _SVID_SOURCE	* glibc2 needs this *
 *     #include <time.h>
 *
 *     int stime(time_t *t);
 *
 * Description
 *     stime sets the system's idea of the time and date. Time,
 *     pointed to by t, is measured in seconds from 00:00:00 GMT
 *     January 1, 1970. stime() may only be executed by the super
 *     user.
 */

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

main()
{
	int hour;
	struct tm *now;
	time_t timer;
	timer = time(NULL);
	now = localtime(&timer);

	/* menbers of sturct tm */
	printf("tm_sec = %d\n", now->tm_sec);                    
	printf("tm_min = %d\n", now->tm_min);                    
	printf("tm_hour = %d\n", now->tm_hour);                   
	printf("tm_mday = %d\n", now->tm_mday);                   
	printf("tm_mon = %d\n", now->tm_mon);                    
	printf("tm_year = %d\n", now->tm_year);                   
	printf("tm_wday = %d\n", now->tm_wday);                   
	printf("tm_yday = %d\n", now->tm_yday);                   
	printf("tm_isdst = %d\n", now->tm_isdst);                  

	printf("tm_gmtoff = %ld\n", now->tm_gmtoff);            
	printf("tm_zone = %s\n", now->tm_zone);         

	printf("%s", asctime(localtime(&timer)));
	hour = now->tm_hour;
	now->tm_hour = (hour + 1) % 24;
	timer = mktime(now);
	stime(&timer);
	time(&timer);
	printf("%s", asctime(localtime(&timer)));
	hour = now->tm_hour;
	now->tm_hour = (hour - 1) % 24;
	timer = mktime(now);
	stime(&timer);
	time(&timer);
	printf("%s", asctime(localtime(&timer)));
}