konsole killing child processes on exit, and midnight commander...

[chconnor]

Scenario 1:

I am in a konsole bash session. I run this command:

konsole

...and then in that window I run midnight commander with

mc

...then open an mp3 file in vlc, and then go back to the mc window and hit control-c, midnight commander exits, and then I "exit" the konsole window and the vlc process continues to run, as desired.


Scenario 2:

I am in a konsole bash sesion and enter:

konsole -e mc

...and then use mc to open an mp3 file with vlc. Then when I ctrl-c in midnight commander, both the konsole window and vlc die.


Why is running the command in konsole with -e causing its child processes to die when it dies, but opening it without -e and running a child process does not cause this? I notice that in scenario 1, if instead of typing "exit" I instead alt-f4 and kill the window, then it does kill vlc, just like in scenario 2. From this I deduce that when you ctrl-c a process in a "konsole -e" session, it sends SIGHUP or SIGKILL or whatever to all child processes.

The reason I'm struggling with this is that I want to call up mc with a keyboard shortcut, be able to spawn child processes (like vlc playing a file) and the ctrl-c the mc window and have the vlc survive, but I can't figure out how to make it work.

Any idea of how I can tell konsole that the -e process should live on as a background process? Or any other way around this? I tried going into the menu of mc and doing exit that way (rather than ctrl-c) but it had the same result.

[chconnor]

Man, I'm really pulling my hair out on this one. I've tried six different convoluted methods and can't find a solution...

It seems like the rule is "when a command is started via konsole -e, or via krunner, or even xterm -e, then when that process exits, slaughter all the child processes no matter what."

Another example:

- in konsole, run "konsole -e bash"
- in that new konsole/bash shell, run "vlc &"
- now, if you "exit" from the bash shell, vlc continues to live. But if you alt-F4 the konsole window, vlc dies with the konsole. Why?
- if instead of "exit" you run "disown" and then alt-F4 the konsole window, vlc does not die.

Great, so if we just "disown" within the bash shell, it's children will live on even if the konsole window is killed!

However:

- make /tmp/myscript and mark it executable with the following contents:

#!/bin/bash
vlc &
disown
sleep 4

- from a konsole window run "konsole -e /tmp/myscript"... as soon as the sleep expires, everything dies, including vlc. Why? This also happens for xterm -e. However at this point krunner will actually work (!?).

However: if I add a nohup:

#!/bin/bash
nohup vlc &
disown
sleep 4

...it does not die when started with konsole -e. Great, so I can just use nohup!

However: in my scenario I need to use xdg-open, not vlc, and xdg-open (by way of kde-open5) just returns without any information about what was launched. So even if I "nohup xdg-open" is has no effect because the "real" process wasn't nohup'ed, and everything dies whenever the konsole window exits.

Any ideas? All I want to do is use mc to launch apps and then go away without tearing everything down when it closes... seems like it shouldn't be this darn hard!