Description

Timeout is a command-line utility that runs a specified command and terminates it if it is still running after a given period of time.

In other words, timeout allows you to run a command with a time limit.

You can set a time limit for any command you want. If the time expires, the command stops executing.

Here, we are going to learn two methods on how you can use a time limit in your commands.

Run Linux Commands Using the timeout Tool

Linux has a command-line utility called a timeout, which enables you to execute a command with a time limit.

Its syntax is as follows.

timeout [OPTION] DURATION COMMAND [ARG]…

To use the command, you specify a timeout value (in seconds) with the command you want to run.

For instance, to timeout a ping command after 5 seconds, you can run the following command.

timeout 5s ping jaipurhosting.com

You do not have to specify the (s) after number 5. The command below is the same and will still work.

timeout 5 ping jaipurhosting.com

Other suffixes include:

m representing minutes
h representing hours
d representing days

Sometimes commands may continue to run even after timeout sends the initial signal. In such instances, you can use the –kill-after option.

Here’s the syntax.

-k, --kill-after=DURATION

You need to specify a duration to let timeout know after how much time the kill signal is to be sent.

For example, the command shown is going to be terminated after 8 seconds.

timeout 8s tail -f /var/log/syslog

Run Linux Commands Using Timelimit Program

The Timelimit program runs a given command then terminates the process after a specified time using a given signal. It initially passes a warning signal, and then after a timeout, it sends the kill signal.

Unlike the timeout option, Timelimit has more options such as killsig, warnsig, killtime, and warntime.

Timelimit can be found in the repositories of Debian-based systems and to install it, use the following command.

sudo apt install timelimit

For Arch-based systems, you can install it using AUR helper programs e.g., Pacaur Pacman, and Packer.

Pacman -S timelimit
pacaur -S timelimit
packer -S timelimit

After installation, run the following command and specify the time.

Here, we can use 10 seconds.

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

Note that if you don’t specify arguments, Timelimit uses the default values: warntime=3600 seconds, warnsig=15, killtime=120, and killsig=9.

Conclusion

Here, we have learned how to run commands with a time limit in Linux. In review, you can use the Timeout command or the Timelimit utility.

The Timeout command is easy to use, but the Timelimit utility is a bit complicated but has more options.

You can choose the most suitable option depending on your needs.