https://faq.i3wm.org/questions/Frequently asked questions and answers about the i3 window managerenCopyright i3, 2012Tue, 14 Jul 2015 09:56:00 +0000https://faq.i3wm.org/question/823/can-i-watch-a-process-with-i3status-and-run_watch-without-a-pidfile/I'd like to check if any process named 'foo' is running. If more than one is running, that's okay. This process doesn't create a PID file.Tue, 27 Nov 2012 00:07:23 +0000https://faq.i3wm.org/question/823/can-i-watch-a-process-with-i3status-and-run_watch-without-a-pidfile/https://faq.i3wm.org/question/823/can-i-watch-a-process-with-i3status-and-run_watch-without-a-pidfile/?comment=6287#comment-6287I want to do this too. It would be perfect to have run_watch accept output of `pidof` command.Tue, 14 Jul 2015 09:56:00 +0000https://faq.i3wm.org/question/823/can-i-watch-a-process-with-i3status-and-run_watch-without-a-pidfile/?comment=6287#comment-6287https://faq.i3wm.org/question/823/can-i-watch-a-process-with-i3status-and-run_watch-without-a-pidfile/?answer=824#post-id-824I think you have two options here. - Make a wrapper for i3status which checks if process runs. - Or make a wrapper for your command which writes the PID to the file for you. Simple shell script like this could solve it. #!/bin/bash PID_FILE=your_file.pid trap "rm -f $PID_FILE" EXIT your_command & echo $! > $PID_FILE wait $! ret=$? exit $ret EDITED: the script above works only if you have only one instance If you need to run more instaces of that process you can extend the script to something like this. #!/bin/bash PID_FILE=t.pid COMMAND=sleep ARGS=15 exit_h() { kill -TERM $! 2> /dev/null RUN=`pidof -o $! $COMMAND | cut -d' ' -f1` if [ ! -z $RUN ];then echo $RUN > $PID_FILE else rm -f $PID_FILE fi } trap "exit_h" EXIT $COMMAND $ARGS & echo $! > $PID_FILE wait $! exit $? The pid can be reused and script should still work (because the file gets deleted). However there is possible race condition if all processes exit at the same time. There is a small chance that pidfile remains undeleted. But that still does not matter unless the pid in that file gets reused. So overall chance of this failure is close to zero i think. I would say it never happens in my life but it's possible so do not use this to control nuclear power plant. Tue, 27 Nov 2012 01:04:00 +0000https://faq.i3wm.org/question/823/can-i-watch-a-process-with-i3status-and-run_watch-without-a-pidfile/?answer=824#post-id-824