Detaching processes from the current bash session

categories:

• Bash
• Linux

A bit of explanations :

$ help disown disown: disown [-h] [-ar] [jobspec ...] By default, removes each JOBSPEC argument from the table of active jobs. If the -h option is given, the job is not removed from the table, but is marked so that SIGHUP is not sent to the job if the shell receives a SIGHUP. The -a option, when JOBSPEC is not supplied, means to remove all jobs from the job table; the -r option means to remove only running jobs.

And a slice of example :

1. Let’s open a terminal
2. We launch a very long process in background : ./myprocess.sh &
3. We type : disown XXXX where XXXX is the PID of the bash command running myprocess.sh
4. We close the terminal
5. We open a new terminal, we type “ps faux” and notice myprocess.sh is still running

It’s possible to start the command like this : “./myprocess.sh & disown”

disown allows you to detach a process from the currently running bash session, this can come in handy if you forgot to launch the process in a screen session or with nohup and you need to close the current session.

If you want to make some tests, myprocess.sh could look like this :

#!/bin/bash until [ ! blah ]; do sleep 1; done

Links :

nohup : http://blog.wains.be/post/nohup/

screen : http://www.gnu.org/software/screen/