As far as I understood from the books and bash manuals is that. When a user logs out from bash all the background jobs that is started by the user will automatically terminate, if he is not using nohup or disown. But today I tested it :
- Logged in to my gnome desktop and accessed gnome-terminal.
There are two tabs in the terminal and in one I created a new user called test and logged in as test
su - test
started a script.
cat test.sh
#!/bin/bash
sleep 60
printf "hello world!!"
exit 0
./test.sh &
After that I logged out of test and closed the tab
- In the next tab I exected ps aux as root and found that job is still running.
How this is happening ?
Whether running background jobs are terminated on exit depends on the shell. Bash normally does not do this, but can be configured to for login shells (shopt -s huponexit). In any case, access to the tty is impossible after the controlling process (such as a login shell) has terminated.
Situations that do always cause SIGHUP include:
- Anything in foreground when the tty is closed down.
- Any background job that includes stopped processes when their shell terminates (
SIGCONT and SIGHUP). Shells typically warn you before letting this happen.
huponexit summary:
On: Background jobs will be terminated with SIGHUP when shell exits
$ shopt -s huponexit
$ shopt huponexit
huponexit on
Off: Background jobs will NOT be terminated with SIGHUP when shell exits.
$ shopt -u huponexit
$ shopt huponexit
huponexit off
Only interactive shells kill jobs when you close them. Other shells (for example those you get by using su - username) don't do that. And interactive shells only kill direct subprocesses.
