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How to run commands regularly in Linux? I believe that many inexperienced people are at a loss about this, so this article summarizes the causes and solutions of the problem. Through this article, I hope you can solve this problem.

Method 1-use the timeout command

The most common method is to use the timeout command. For those who don't know, the timeout command can effectively limit the absolute execution time of a process. The timeout command is part of the GNU coreutils package, so it is pre-installed on all GNU/Linux systems.

Suppose you just want to run a command for 5 seconds and then kill it. To do this, we use:

$timeout

For example, the following command will terminate after 10 seconds.

$timeout 10s tail-f / var/log/pacman.log

You don't have to add the suffix s after the seconds. The following command is the same as the one above.

$timeout 10 tail-f / var/log/pacman.log

Other available suffixes are:

M stands for minutes.

H stands for hours.

D stands for days.

If you run this tail-f / var/log/pacman.log command, it will continue to run until you press CTRL+C to end it manually. However, if you run it with the timeout command, it will automatically terminate after a given interval. If the command is still running after the timeout, you can send a kill signal, as shown below.

$timeout-k 20 10 tail-f / var/log/pacman.log

In this case, if the tail command is still running after 10 seconds, the timeout command will send a kill signal after 20 seconds and end.

For more details, see the man page.

$man timeout

Sometimes, a particular program may take a long time to complete and eventually freeze your system. In this case, you can use this technique to automatically end the process after a specific time.

Method 2-use the timelimit program

Timelimit executes the given command with the supplied parameters and terminates the process with the given signal after the given time. First, it sends a warning signal, and then sends a kill signal after the timeout.

Unlike timeout, timelimit has more options. You can pass the number of parameters, such as killsig, warnsig, killtime, warntime, etc. It exists in the default repository of Debian-based systems. So, you can use the command to install it:

$sudo apt-get install timelimit

For Arch-based systems, it exists in AUR. Therefore, you can use any AUR helper for installation, such as Pacaur, Packer, Yay, Yaourt, etc.

For other distributions, please download the source code here and install it manually. After installing timelimit, run the following command to execute for a specific period of time, for example, 10 seconds:

$timelimit-t10 tail-f / var/log/pacman.log

If you run timelimit without any parameters, it uses the default values: warntime=3600 seconds, warnsig=15 seconds, killtime=120 seconds, killsig=9. For more details, see the man pages and project website at the end of this guide.

$man timelimit

After reading the above, have you mastered how to run commands regularly in Linux? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel, thank you for reading!

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