How to use time command.

How To Use Time Command.

In this article we will show you how to use time command.

For example, if you have two different scripts doing the same job and you want to know which one performs better you can use the Linux time command to determine the duration of execution of each script.


Time Command Versions

type time
# Bash
time is a shell keyword

# Zsh
time is a reserved word

# GNU time (sh)
time is /usr/bin/time


Using Linux Time Command.

time wget

What will be printed as an output depends on the version of the time command you’re using:

# Bash
real	0m33.961s
user	0m0.340s
sys	0m0.940s

# Zsh
0.34s user 0.94s system 4% cpu 33.961 total

# GNU time (sh)
0.34user 0.94system 0:33.96elapsed 4%CPU (0avgtext+0avgdata 6060maxresident)k
0inputs+201456outputs (0major+315minor)pagefaults 0swaps
  • real or total or elapsed (wall clock time) is the time from start to finish of the call. It is the time from the moment you hit the Enter key until the moment the wget command is completed.

  • user – amount of CPU time spent in user mode.

  • system or sys – amount of CPU time spent in kernel mode.



By now you should have a good understanding of how to use the time command.