How To Run Programs in the Background from Terminal

In the world of system administration and programming, the terminal is an essential tool. It allows users to interact with the system, run programs, and perform various tasks. One common requirement is the ability to run programs in the background, freeing up the terminal for other tasks and allowing the program to continue running even if the terminal is closed. In this article, we will explore several methods to accomplish this.

Using the nohup Command

The nohup command is a popular method to run programs in the background. The term nohup stands for “no hangup”. This command ignores the HUP (hangup) signal, which allows the command to continue running even after the terminal is closed.

Here is how you can use nohup:

nohup command-to-be-run &

In this command, command-to-be-run is the program you want to run in the background. The & at the end of the command tells the system to run the command in the background.

For example:

nohup nm-applet &

This command will run nm-applet in the background and allow you to close the terminal without affecting the program.

Using the setsid Command

Another option is to use the setsid command. The setsid command runs a program in a new session, which allows the program to continue running even after the terminal is closed.

Here is how you can use setsid:

setsid command-to-be-run

For example:

setsid nm-applet

This command will run nm-applet in a new session, detached from the terminal.

Using Subshells

Subshells are another method to run a program in the background. A subshell is a child process launched by a shell (or shell script).

Here is how you can use a subshell:

(command-to-be-run &)

For example:

(nm-applet &)

This command will start nm-applet in a subshell, allowing you to close the terminal without affecting the program.

Using Terminal Multiplexers

For more advanced needs, you can use terminal multiplexers like screen or tmux. These tools allow you to create and manage multiple terminal sessions. You can detach from a session and reattach to it later, even after closing the terminal.

Here is how you can use screen:

screen -S session-name

In this command, session-name is the name of the session. After running this command, you will be in a new session where you can run your program. To detach from the session, press Ctrl-A followed by D.

To reattach to the session, use:

screen -r session-name

For example:

screen -S mysession

This command will create a new session named mysession. You can then run your program in this session and detach from it without affecting the program.

These are just a few methods to run programs in the background from the terminal. The best method depends on your specific needs and the nature of the program you want to run. Remember to check the documentation or man pages for each command to learn more about their specific options and usage. Happy coding!