calling shell scripts creates zombie processes
Posted: Fri Jan 03, 2025 6:45 pm
Raspberry PI 4 running Bullseye
and
QLC+ 4.12.3 (installed via APT)
the system and QLC runs 24/7 like a charm - except:
in the virtual console i implemented some buttons - each of them triggering a shell (BASH) script like:
systemcommand:/home/pi/camera_on.sh
with the script
each script call resulting in a zombie process
those processes get deleted when i close QLC+.
but i want to keep it running.
double forking did not help.
i guess it's QLC that should check (via "wait"?) its' subprocesses...
did anyone encounter this behaviour or has any clue how to prevent zombie processes?
thanks and greetings.
and
QLC+ 4.12.3 (installed via APT)
the system and QLC runs 24/7 like a charm - except:
in the virtual console i implemented some buttons - each of them triggering a shell (BASH) script like:
systemcommand:/home/pi/camera_on.sh
with the script
Code: Select all
#!/bin/bash
libcamera-hello --width 800 --height 600 -t 0 --ev 1 --brightness 0.1 --contrast 1 --framerate 12
exit 0Code: Select all
pi@pimobile01:~$ ps aux | grep defunct
pi 3500 0.0 0.0 0 0 ? Z Jan01 0:00 [camera_on.sh] <defunct>
pi 3595 0.0 0.0 0 0 ? Z Jan01 0:00 [camera_off.sh] <defunct>
pi 4178 0.0 0.0 0 0 ? Z Jan01 0:00 [camera_on.sh] <defunct>
pi 4205 0.0 0.0 0 0 ? Z Jan01 0:00 [video_play.sh] <defunct>
pi 4217 0.0 0.0 0 0 ? Z Jan01 0:00 [video_stop.sh] <defunct>
pi 4223 0.0 0.0 0 0 ? Z Jan01 0:00 [bmr_116_on.sh] <defunct>
pi 4228 0.0 0.0 0 0 ? Z Jan01 0:00 [bmr_116_off.sh] <defunct>
pi 4233 0.0 0.0 0 0 ? Z Jan01 0:00 [bmr_116_blackou] <defunct>
pi 4235 0.0 0.0 0 0 ? Z Jan01 0:00 [bmr_116_blackof] <defunct>
pi 5862 0.0 0.0 0 0 ? Z Jan01 0:00 [camera_off.sh] <defunct>but i want to keep it running.
double forking did not help.
i guess it's QLC that should check (via "wait"?) its' subprocesses...
did anyone encounter this behaviour or has any clue how to prevent zombie processes?
thanks and greetings.