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I'm trying to measure the execution time of a process that I call via the command line (i.e., I want to find out how long it takes to for the process to finish). Is there any command that I can add to the command calling the process that will achieve this?

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203

Add time before the command you want to measure. For example: time ls.

The output will look like:

real    0m0.606s
user    0m0.000s
sys     0m0.002s

Explanation on real, user and sys (from man time):

  • real: Elapsed real (wall clock) time used by the process, in seconds.
  • user: Total number of CPU-seconds that the process used directly (in user mode), in seconds.
  • sys: Total number of CPU-seconds used by the system on behalf of the process (in kernel mode), in seconds.
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    @ninjalj, can you provide more information on what the real, user, and sys times are that this command returns? – Christopher Kyle Horton Jul 17 '11 at 20:22
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    @JacobVlijm This answer isn't that elaborate. :) You could edit in your comment and make it so. – muru Feb 13 '15 at 16:43
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    Note that you may need sudo apt-get install time if you are using a shell where time is not a builtin. – poolie Oct 26 '16 at 16:45
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    Note that this is the output from Bash's time builtin, but man time would be about an executable (like /usr/bin/time, from the time package), and its output would look different. Also in Bash, you can run help time for help with the builtin. – wjandrea Mar 25 at 21:08
  • Note that the process end does not mean all the work is finished. A copy may take additional minutes after the "time" returns for flushing system bufffers (therefor with unallocated sys time also). – ubfan1 Jun 23 at 16:25
43

For a line-by-line delta measurement, try gnomon.

It is a command line utility, a bit like moreutils's ts, to prepend timestamp information to the standard output of another command. Useful for long-running processes where you'd like a historical record of what's taking so long.

Piping anything to gnomon will prepend a timestamp to each line, indicating how long that line was the last line in the buffer--that is, how long it took the next line to appear. By default, gnomon will display the seconds elapsed between each line, but that is configurable.

gnomon demo

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    This is pretty slick. – Nathan GoFundMonica Arthur Sep 8 '16 at 21:53
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    (typo in link, fortunately URL ok). You can install it with sudo npm i gnomon -g if you have npm. Not sure how well it does against "progress" lines using '\r' (staying on the same line): in that case I'd like it counting it all as one long line, not separate ones. – Tomasz Gandor Jun 14 '17 at 21:42
  • so we pipe it to gnomon ! thats it ? – Ciasto piekarz May 15 '18 at 9:44
26

You can use time:

time ls -R
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8
date +"%T" && cp -r ./file  /destination/folder/here && date +"%T"

Running this command in the terminal will give you the total time for coping a file

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  • This will give you the start time and end time, not the duration. – wjandrea Mar 25 at 19:31
  • This is a good answer, under some circumstances. For example, the following find command -- without the 2>/dev/null redirect -- gives copious Permission denied messages. However, adding 2>/dev/null to that command breaks the time portion of that command. The following provides a good compromise: START="$(date +"%s")" && find 2>/dev/null / -path /mnt -prune -o -name "*libname-server-2.a*" -print; END="$(date +"%s")"; TIME="$((END - START))"; printf 'find command took %s sec\n' "$TIME", giving (e.g.) /usr/lib/libname-server-2.a find command took 3 sec as the sole output. – Victoria Stuart May 22 at 3:45
  • An addendum to my comment: of course, you can simply run time sudo find / -path /mnt -prune -o -name "*libname-server-2.a*" -print (i.e., as sudo) -- avoiding those numerous Permission denied warnings. – Victoria Stuart May 22 at 16:04
4

Occasionally I find myself needing a stopwatch to count how long it takes for an action like my app booting, in which case many of the solutions here are not useful.

For this I like to use sw.

sw

Install

wget -q -O - http://git.io/sinister | sh -s -- -u https://raw.githubusercontent.com/coryfklein/sw/master/sw

Usage

sw
 - start a stopwatch from 0, save start time in ~/.sw
sw [-r|--resume]
 - start a stopwatch from the last saved start time (or current time if no last saved start time exists)
 - "-r" stands for --resume
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1
time -v command

-v gives more information

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