nohup
is a command in Unix and Unix-like operating systems that allows a process to keep running after the terminal session has ended. It stands for “No Hangups”.- The
nohup
command prevents the process from receiving theSIGHUP
(Signal Hang UP) signal, which is sent when the terminal session ends. By default, this signal causes the process to terminate[^Source 1^][^Source 3^].
Here is an example of how to use nohup
:
nohup command &
In this command, command
is the process you want to run. The &
at the end puts the command in the background, freeing up the terminal for other commands.
The output of the process is usually directed to a file named nohup.out
. If you want to redirect the output to a different file, you can use the >
operator:
nohup command > outputfile &
In this command, outputfile
is the name of the file where you want to store the output[^Source 3^].
It’s important to note that nohup
is different from a daemon. While both allow a process to run in the background, nohup
is designed for processes that need to run to completion, whereas a daemon is designed for processes that run continuously in the background[^Source 0^].
Finally, remember that if a process started with nohup
tries to interact with the terminal (for example, by asking for input), it will fail because the terminal is no longer available[^Source 4^].