What is nohup in Linux ?

In Linux and other Unix-like operating systems, `nohup` is a command used to execute a command immune to hangups, so that the command can continue running even if the user who started the command logs out or the terminal session ends. The name "nohup" is short for "no hangup".

When a user starts a command or a script in a terminal session, the process is typically tied to the session, which means that if the session ends or the user logs out, the process will be terminated. This can be a problem for long-running commands or scripts that need to continue running even if the user is not logged in.

The `nohup` command solves this problem by detaching the command or script from the terminal session and making it immune to hangups. This allows the process to continue running even after the terminal session ends.

When a user runs a command with `nohup`, any output that would normally go to the terminal is redirected to a file called `nohup.out` in the current directory. This file can be used to monitor the progress of the command or to check for any errors that may have occurred.

Here's an example of how to use `nohup` to run a long-running command in the background:

nohup command-to-run &

In this example, `command-to-run` is the command you want to run, and the `&` symbol runs the command in the background. The output from the command will be redirected to `nohup.out` in the current directory.

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