방법1)
두개의 시간 차이를 구하기
time.h 파일에 struct timeval 는 아래와 같이 되어 있다.
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struct timeval {
time_t tv_sec; /* seconds */
suseconds_t tv_usec; /* and microseconds */
};
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#include <time.h>
int main(int argc, char *argv[])
{
struct timeval timeStart;
struct timeval timeEnd;
struct timeval timeDiff;
/* 시작시점 기록 */
gettimeofday( &timeStart, NULL );
printf("STARRT_TIME sec[%ld] usec[%ld]\n", timeStart.tv_sec, timeStart.tv_usec);
/* 실제 처리 작업 수행 */
/* function() */
/* 종료시점 기록 */
gettimeofday( &timeEnd, NULL );
printf("END____TIME sec[%ld] usec[%ld]\n", timeEnd.tv_sec, timeEnd.tv_usec);
/* 처리 시간 계산 */
timeDiff.tv_sec = timeEnd.tv_sec - timeStart.tv_sec;
timeDiff.tv_usec = timeEnd.tv_usec - timeStart.tv_usec;
if( timeDiff.tv_usec < 0 )
{
timeDiff.tv_sec = timeDiff.tv_sec - 1;
timeDiff.tv_usec = timeDiff.tv_usec + 1000000;
}
printf("DIFF___TIME sec[%ld] usec[%ld]\n", timeDiff.tv_sec, timeDiff.tv_usec);
}
처리 결과
###############################################
STARRT_TIME sec[1299839608] usec[359494]
END____TIME sec[1299839608] usec[359964]
DIFF___TIME sec[0] usec[470]
###############################################
방법2)두개의 시간 차이를 구하기
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#include<time.h>
int main()
{
time_t start,end;
double dif;
time (&start);
sleep(10);
time (&end);
dif = difftime (end,start);
printf ("%lf\n", dif );
return 0;
}
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Standard C Library Functions difftime(3C)
NAME
difftime - computes the difference between two calendar times
SYNOPSIS
#include <time.h>
double difftime(time_t time1, time_t time0);
DESCRIPTION
The difftime() function computes the difference between two calendar times.
RETURN VALUES
The difftime() functions returns the difference (time1 - time0) expressed in seconds as a double.
USAGE
The difftime() function is provided because there are no general arithmetic properties defined for type time_t.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Interface Stability | Standard |
|_____________________________|_____________________________|
| MT-Level | MT-Safe |
|_____________________________|_____________________________|
SEE ALSO
ctime(3C), attributes(5), standards(5)
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