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clock_t

From cppreference.com
< c‎ | chrono
Defined in header <time.h>
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.

[edit] 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);
}

Possible output:

for loop took 0.033492 seconds to execute

[edit] 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

[edit] See also

returns raw processor clock time since the program is started
(function) [edit]
number of processor clock ticks per second
(macro constant) [edit]
C++ documentation for clock_t