Thread: Timing C program always returns 0 seconds.

Hi,

I was looking at the programming FAQ and I saw an example method of timing a program in c. So, I tried out the example below and compiled it using the plain gcc under ubuntu. eg.
gcc version 4.1.2 20060928 (prerelease) (Ubuntu 4.1.1-13ubuntu5). After running the compiled executable from below - I always get 0.000 seconds despite waiting a few seconds before hitting return. Would I have overlooked something?

Code:

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

int main ( void )
{
  clock_t start, end;

  /* Start the timer */
  start = clock();

  printf ( "Please wait a few moments and hit return\n" );
  getchar();

  /* End the timer */
  end = clock();

  /* Print out the difference */
  printf ( "The interval was: %f seconds\n",
    (double)( end - start ) / (double)CLOCKS_PER_SEC );

  return 0;
}