How to measure the execution time of a function in C?

Here we will see how to calculate the time spent by a process. For this problem, we will use the clock() function. The clock() function is located in the time.h header file.

To get the elapsed time, we can use clock() to get the time at the beginning of the task, use clock() again to get the time at the end of the task, and then subtract the two values ​​to get the difference. We then divide the difference by CLOCK_PER_SEC (clock ticks per second) to get the processor time.

Example

#include <stdio.h>
#include <time.h>
void take_enter() {
   printf("Press enter to stop the counter </p><p>");
   while(1) {
      if (getchar())
      break;
   }
}
main() {
   // Calculate the time taken by take_enter()
   clock_t t;
   t = clock();
   printf("Timer starts</p><p>");
   take_enter();
   printf("Timer ends </p><p>");
   t = clock() - t;
   double time_taken = ((double)t)/CLOCKS_PER_SEC; // calculate the elapsed time
   printf("The program took %f seconds to execute", time_taken);
}

Output

Timer starts
Press enter to stop the counter
Timer ends
The program took 5.218000 seconds to execute

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