nohup and &: let the process run safely in the background

Title: nohup and &: Let the process run safely in the background

In the Linux system, the two commands nohup and & are very commonly used. They can allow our programs to run in the background without being affected by Effect of terminal shutdown. This article will introduce the usage and difference of nohup and & commands, and how they help us ensure that the process runs safely in the background.

First, let’s take a look at the nohup command. The nohup command is used to disable hangs when running commands in the background. Its syntax is generally:

nohup command &

The command here can be any command you want to run, and the & symbol means running in the background. The advantage of using the nohup command is that even if the user exits the current terminal window, the started process will not be affected and will continue to run in the background. This is useful for long-running tasks such as data backup, file transfer, etc.

Another common method is to use the & symbol to run the command in the background. The syntax of the & symbol is:

command &

Unlike the nohup command, processes started with the & symbol are affected when the terminal is closed because they are still associated with the current terminal session. But if your task doesn’t need to run in the background for a long time, the ampersand is also a good choice.

It should be noted that the nohup command usually redirects the output to a file named nohup.out, which allows us to view the output of the process at any time. A process started using the & symbol will print the output directly to the current terminal. If the output is not needed, it can be blocked by redirection.

In general, the two commands nohup and & are good choices for letting the process run safely in the background. Whether you need to keep a process running for a long time or just don't want to be interrupted by a terminal shutdown for a while, they can help you achieve the desired effect. Remember to choose the appropriate method according to your own needs when using it, so that the process can run smoothly in the background.

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