gettime.cpp

C++编的关于的获取实时系统时间小程序

#include <time.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/timeb.h>
#include <string.h>

void main()
{
	char tmpbuf[128], ampm[] = "AM";
	time_t ltime;
	struct _timeb tstruct;
	struct tm *today, *gmt, xmas = { 0, 0, 12, 25, 11, 93 };
	
	/* 在TZ环境变量中设置时区，如果TZ没有设置，系统采用默认的设置 */
	_tzset();
	
	/* 显示系统时间和日期 */
	_strtime( tmpbuf );
	printf( "OS time:\t\t\t\t%s\n", tmpbuf );
	_strdate( tmpbuf );
	printf( "OS date:\t\t\t\t%s\n", tmpbuf );
	
	/* 获得UNIX-时间并且按字符串和数字显示 */
	time( &ltime );
	printf( "Time in seconds since UTC 1/1/70:\t%ld\n", ltime );
	printf( "UNIX time and date:\t\t\t%s", ctime( &ltime ) );
	
	/* 显示世界通用时间 */
	gmt = gmtime( &ltime );
	printf( "Coordinated universal time:\t\t%s", asctime( gmt ) );
	
	/* 转换时间类型，并且必要的话显示PM */
	today = localtime( &ltime );
	if( today->tm_hour > 12 )
	{
		strcpy( ampm, "PM" );
		today->tm_hour -= 12;
	}
	if( today->tm_hour == 0 )  
		today->tm_hour = 12;
	
	printf( "12-hour time:\t\t\t\t%.8s %s\n",asctime( today ) + 11, ampm );
	
	/* 打印其余时间信息 */
	_ftime( &tstruct );
	printf( "Plus milliseconds:\t\t\t%u\n", tstruct.millitm );
	printf( "Zone difference in seconds from UTC:\t%u\n",tstruct.timezone );
	printf( "Time zone name:\t\t\t\t%s\n", _tzname[0] );
	printf( "Daylight savings:\t\t\t%s\n",tstruct.dstflag ? "YES" : "NO" );
	
	if( mktime( &xmas ) != (time_t)-1 )
		printf( "Christmas\t\t\t\t%s\n", asctime( &xmas ) );
	
	today = localtime( &ltime );
	strftime( tmpbuf, 128, "Today is %A, day %d of %B in the year %Y.\n", today );
	printf( tmpbuf );
}