How do I measure a time interval in C?

Question

I would like to measure time in C, and I am having a tough time figuring it out, all I want is something like this:

• start a timer
• run a method
• stop the timer
• report the time taken (at least to micro accuracy)

Any help would be appreciated.

(I am compiling in windows using mingw)

Answer 1

Using the time.h library, try something like this:

long start_time, end_time, elapsed;

start_time = clock();
// Do something
end_time = clock();

elapsed = (end_time - start_time) / CLOCKS_PER_SEC * 1000;

Answer 2

If your Linux system supports it, clock_gettime(CLOCK_MONOTONIC) should be a high resolution timer that is unaffected by system date changes (e.g. NTP daemons).