clock

return the number of clock ticks used by the program

Synopsis:

#include <time.h>
clock_t clock(void);

Description:

The clock() function returns the number of clock ticks of processor time used by the program since it started executing. This can be converted to seconds by dividing by the value of the macro CLOCKS_PER_SEC.

Returns:

the number of clock ticks that have occurred since the program started executing

See also:

asctime(), ctime(), difftime(), gmtime(), localtime(), mktime(), strftime(), time(), tzset()

Examples:

#include <stdio.h>
#include <math.h>
#include <time.h>

void compute( void )
  {
    int i, j;
    double x;

    x = 0.0;
    for( i = 1; i <= 100; i++ )
      for( j = 1; j <= 100; j++ )
        x += sqrt( (double) i * j );
    printf( "%16.7f\n", x );
  }

void main()
  {
    clock_t start_time, end_time;

    start_time = clock();
    compute();
    end_time = clock();
    printf( "Execution time was %lu seconds\n",
          (end_time - start_time) / CLOCKS_PER_SEC );
  }

Classification:

ANSI

Systems:

All (except Netware, DOS/PM)