How can I measure the execution time of a terminal process?

Question

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?

Answer 1

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.

Answer 2

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.

Answer 3

You can use time:

time ls -R

Answer 4

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

Answer 5

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.

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

Answer 6

In zsh, the time command's output is slightly different.

To interpret the output:

time sleep 10
sleep 10  0.00s user 0.00s system 0% cpu 10.011 total

The last number gives the total time as though it were recorded with a real life stopwatch (what you want 99% of the time). The other values are explained here.

Answer 7

time -v command

-v gives more information

Answer 8

In Nushell, the command is timeit instead of time.

> timeit java -jar benchmark.jar concurrency
[program output]
3min 42sec 994ms 803µs 978ns