CODE EXAMPLE FOR SHELL

linux c programm time

#include <time.h>

#define CPU_TIME (getrusage(RUSAGE_SELF,&ruse), ruse.ru_utime.tv_sec + 
  ruse.ru_stime.tv_sec + 1e-6 * 
  (ruse.ru_utime.tv_usec + ruse.ru_stime.tv_usec))

int main(void) {
    time_t start, end;
    double first, second;

    // Save user and CPU start time
    time(&start);
    first = CPU_TIME;

    // Perform operations
    ...

    // Save end time
    time(&end);
    second = CPU_TIME;

    printf("cpu  : %.2f secs
", second - first); 
    printf("user : %d secs
", (int)(end - start));
}