C library functions -difftime()
Description
C Library Functionsdouble difftime(time_t time1, time_t time2)returntime1andtime2The number of seconds between(time1 - time2)These two times are specified in calendar time, representing the elapsed time since the Epoch (Coordinated Universal Time UTC: 1970-01-01 00:00:00).
Declaration
Below is the declaration of the difftime() function.
double difftime(time_t time1, time_t time2)
Parameter
- time1-- This is the time_t object representing the end time.
- time2-- This is the time_t object representing the start time.
Return Value
This function returns the number of seconds between the two times (time1 - time2) as a double-precision floating-point double value.
Example
The following example demonstrates the usage of the difftime() function.
Example
#include <stdio.h>
#include <time.h>
#ifdef _WIN32
#include <Windows.h>
#else
#include <unistd.h>
#endif
int main ()
{
time_t start_t, end_t;
double diff_t;
printf("Program starting...\n");
time(&start_t);
printf("Sleep for 5 seconds...\n");
sleep(5);
time(&end_t);
diff_t = difftime(end_t, start_t);
printf("Execution time = %f\n", diff_t);
printf("Exiting program...\n");
return(0);
}
Let us compile and run the above program, which will produce the following results:
程序启动... 休眠 5 秒... 执行时间 = 5.000000 程序退出...other extensions