linux下获取系统时间的方法.doc

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1.¿ÉÒÔÓÃlocaltimeº¯Êý·Ö±ð»ñÈ¡ÄêÔÂÈÕʱ·ÖÃëµÄÊýÖµ¡£

#include<time.h>//CÓïÑÔµÄÍ·Îļþ

#include<stdio.h>//C﵀I/O

voidmain()

{

time_tnow;//ʵÀý»¯time_t½á¹¹

structtm*timenow;//ʵÀý»¯tm½á¹¹Ö¸Õë

time(&now);

//timeº¯Êý¶ÁÈ¡ÏÖÔÚµÄʱ¼ä(¹ú¼Ê±ê׼ʱ¼ä·Ç±±¾©Ê±¼ä)£¬È»ºó´«Öµ¸ønow

timenow=localtime(&now);

//localtimeº¯Êý°Ñ´ÓtimeÈ¡µÃµÄʱ¼änow»»Ëã³ÉÄãµçÄÔÖеÄʱ¼ä(¾ÍÊÇÄãÉèÖõĵØÇø)

printf("Localtimeis%s\n",asctime(timenow));

//ÉϾäÖÐasctimeº¯Êý°Ñʱ¼äת»»³É×Ö·û£¬Í¨¹ýprintf()º¯ÊýÊä³ö

}

×¢ÊÍ£ºtime_tÊÇÒ»¸öÔÚtime.hÖж¨ÒåºÃµÄ½á¹¹Ìå¡£¶øtm½á¹¹ÌåµÄÔ­ÐÎÈçÏ£º

structtm

{

inttm_sec;//seconds0-61

inttm_min;//minutes1-59

inttm_hour;//hours0-23

inttm_mday;//dayofthemonth1-31

inttm_mon;//monthssincejan0-11

inttm_year;//yearsfrom1900

inttm_wday;//dayssinceSunday,0-6

inttm_yday;//dayssinceJan1,0-365

inttm_isdst;//DaylightSavingtimeindicator

};

2.¶ÔijЩÐèÒª½Ï¸ß¾«×¼¶ÈµÄÐèÇó£¬LinuxÌṩÁËgettimeofday()¡£

#include<stdio.h>

#include<stdlib.h>

#include<sys/time.h>

intmain(intargc,char**argv)

{

structtimstart,stop,diff;

gettimeofday(&start,0);

//×öÄãÒª×öµÄÊÂ...

gettimeofday(&stop,0);

tim_subtract(&diff,&start,&stop);

printf("×ܼÆÓÃʱ:%dºÁÃë\n",diff.tv_usec);

}

inttim_subtract(structtim*result,structtim*x,structtim*y)

{

intnsec;

if(x->tv_sec>y->tv_sec)

return-1;

if((x->tv_sec==y->tv_sec)&&(x->tv_usec>y->tv_usec))

return-1;

result->tv_sec=(y->tv_sec-x->tv_sec);

result->tv_usec=(y->tv_usec-x->tv_usec);

if(result->tv_usec<0)

{

result->tv_sec--;

result->tv_usec+=1000000;

}

return0;

}

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