clock_t

typedef /* unspecified */ clock_t;

Arithmetic (until C11)Real (since C11) type capable of representing the processor time used by a process. It has implementation-defined range and precision.

Example

#include <stdio.h>
#include <time.h>
 
volatile unsigned sink;
int main (void)
{
  clock_t start = clock();
 
  for(size_t i=0; i<10000000; ++i)
      sink++;
 
  clock_t end = clock();
  double cpu_time_used = ((double) (end - start)) / CLOCKS_PER_SEC;
 
  printf("for loop took %f seconds to execute \n", cpu_time_used);
}

for loop took 0.033492 seconds to execute

References

• C11 standard (ISO/IEC 9899:2011):
• 7.27.1/3 Components of time (p: 388)
• C99 standard (ISO/IEC 9899:1999):
• 7.23.1/3 Components of time (p: 338)
• C89/C90 standard (ISO/IEC 9899:1990):
• 4.12.1 Components of time

See also