C++: How would I get unix time?

Question

I need a function or way to get the UNIX epoch in seconds, much like how I can in PHP using the time function.

I can't find any method except the time() in ctime which seems to only output a formatted date, or the clock() function which has seconds but seems to always be a multiple of 1 million, nothing with any resolution.

I wish to measure execution time in a program, I just wanted to calculate the diff between start and end; how would a C++ programmer do this?

EDIT: time() and difftime only allow resolution by seconds, not ms or anything too btw.

Answer 1

time() should work fine, use difftime for difference of time calculations. In case you need better resolutuion, use gettimeofday.

Also, duplicate of: http://stackoverflow.com/questions/1468596/c-programming-calculate-elapsed-time-in-milliseconds-unix

Answer 2

If you want to profile get, I'd recommend using getrusage. This will allow you to track CPU time instead of wall clock time:

struct rusage ru;
getrusage(RUSAGE_SELF, &ru);

ru.ru_utime.tv_sec;  // seconds of user CPU time
ru.ru_utime.tv_usec; // microseconds of user CPU time
ru.ru_stime.tv_sec;  // seconds of system CPU time
ru.ru_stime.tv_usec; // microseconds of system CPU time