The shell command ‘nohup‘ in combination with ‘&‘ will allow to send the a command-line instruction in background enabling the process to keep running after the user who issues the command has logged out.
A common use of ‘nohup’ is when you need to issue a remote command via ssh connection and then you need to close the connection but be sure that the issued command will keep running in background, i.e.:
~$ sudo nohup shutdown -r -h 1203192100
I use this ‘trick’ when I want to restart my Mac and GNU/Linux Servers during evening/night hours but I want to submit the command during my office time.
In such way I save myself the time to remotely connect from home.
The ‘nohup’ command is even used to run processes in background as daemons.
nohup is a POSIX command to ignore the HUP (hangup) signal
(cit. from Wikipedia)
