How to run a script if the process has terminated?

Question

linux

there is a small script for taking screenshots from the camera, but it sometimes crashes, how to check if it is running and if not, then run it? need on bash

Answer 1

A reliable linux-way way is to create a flag in the form of a file that contains the PID of the process. And then track its status. You can simply set it to run every xx minutes via cron.
FLAGFILE=/tmp/myprocess.flg
if [ -e $FLAGFILE ]; then
read <$FLAGFILE PID
ps $PID >> /dev/null
if [ $? –eq0]; then
echo "Process is already running. Exiting."
exit 1
else
echo "Previous shutdown was incorrect. Continue."
rm $FLAGFILE
fi
fi
echo "$$" > $FLAGFILE
# YOUR SCRIPT HERE
rm $FLAGFILE

Answer 2

see the list of processes - command ps
filter the list - grep
in the same way by checking the output of ps -e | grep [process/script name], you can see if it's running.

Answer 3

supervisord to help you.