.. _cmd-time:

time - measure how long a command or block takes
================================================

Synopsis
--------

**time** *COMMAND*

Description
-----------

.. only:: builder_man

          NOTE: This page documents the fish keyword ``time``.
          To see the documentation on the ``time`` command you might have,
          use ``command man time``.

``time`` causes fish to measure how long a command takes and print the results afterwards. The command can be a simple fish command or a block. The results can not currently be redirected.

For checking timing after a command has completed, check :ref:`$CMD_DURATION <variables-special>`.

Your system most likely also has a ``time`` command. To use that use something like ``command time``, as in ``command time sleep 10``. Because it's not inside fish, it won't have access to fish functions and won't be able to time blocks and such.

Example
-------

(for obvious reasons exact results will vary on your system)

::

   >_ time sleep 1s
   
   ________________________________________________________
   Executed in    1,01 secs   fish           external
      usr time    2,32 millis    0,00 micros    2,32 millis
      sys time    0,88 millis  877,00 micros    0,00 millis

   >_ time for i in 1 2 3; sleep 1s; end

   ________________________________________________________
   Executed in    3,01 secs   fish           external
      usr time    9,16 millis    2,94 millis    6,23 millis
      sys time    0,23 millis    0,00 millis    0,23 millis

Inline variable assignments need to follow the ``time`` keyword::

   >_ time a_moment=1.5m sleep $a_moment

   ________________________________________________________
   Executed in   90.00 secs      fish           external
      usr time    4.62 millis    4.62 millis    0.00 millis
      sys time    2.35 millis    0.41 millis    1.95 millis