Each process has a parent process that started it. For example, if you execute a command in a bash shell, then that command’s parent process is the bash shell process.
When a parent process is stopped, a hang-up (HUP) signal is sent to all the child processes. This HUP signal is designed to stop the child processes. By default, a child process will stop when sent a HUP signal.
To avoid this, execute the child process with the nohup command:
$ nohup some_command
This technique is typically used when you remotely log in to a system and want to have some command continue to run even if you are disconnected. When you are disconnected, all of the programs you have running are sent HUP signals. Using the nohup command allows this specific process to continue running.
nohup Command Options
nohup command only has 2 options as shown below:
| Option | Description |
|---|---|
| –help | display this help and exit |
| –version | output version information and exit |