Programming Perl, 4th Edition

time

time

This function returns the number of nonleap seconds since “the epoch”, traditionally 00:00:00 on January 1, 1970, UTC.^[254] The returned value is suitable for feeding to gmtime and localtime, for comparison with file modification and access times returned by stat, and for feeding to utime.

$start = time();
system("some slow command");
$end   = time();
if ($end – $start > 1) {
    say "Program started: ", scalar localtime($start);
    say "Program ended:   ", scalar localtime($end);
}

For measuring time in finer granularity than integer seconds, use the Time::HiRes module, included with Perl since the v5.8 release and available from CPAN earlier than that.

^[254] Not to be confused with the “epic”, which is about the making of Unix. (Other operating systems may have a different epoch, not to mention a different epic.)