Waiting for background processes to finish before exiting script

If you want to wait for jobs to finish, use wait. This will make the shell wait until all background jobs complete. However, if any of your jobs daemonize themselves, they are no longer children of the shell and wait will have no effect (as far as the shell is concerned, the child is already done. Indeed, when a process daemonizes itself, it does so by terminating and spawning a new process that inherits its role).

#!/bin/sh
{ sleep 5; echo waking up after 5 seconds; } &
{ sleep 1; echo waking up after 1 second; } &
wait
echo all jobs are done!

Leave a Comment

tech