time(2) - perldoc - phpman

Che Dong

⚡ TLDR: time (tldr-pages)

Measure how long a command took to run.

Run the `command` and print the time measurements to `stdout`
time {{command}}
Create a very simple stopwatch (only works in Bash)
time read

    time    Returns the number of non-leap seconds since whatever time the
            system considers to be the epoch, suitable for feeding to
            "gmtime" and "localtime". On most systems the epoch is 00:00:00
            UTC, January 1, 1970; a prominent exception being Mac OS Classic
            which uses 00:00:00, January 1, 1904 in the current local time
            zone for its epoch.

            For measuring time in better granularity than one second, use
            the Time::HiRes module from Perl 5.8 onwards (or from CPAN
            before then), or, if you have gettimeofday(2), you may be able
            to use the "syscall" interface of Perl. See perlfaq8 for
            details.

            For date and time processing look at the many related modules on
            CPAN. For a comprehensive date and time representation look at
            the DateTime module.