Using command timeouts inside of bash scripts

Sometimes one needs to terminate a command after a period of time and this particular command does not offer a timeout function itself. This could be a real show-stopper when it’s about running commands synchronously inside of scripts.

Somehow I didn’t manage to get “timeout” from the coreutils working correctly inside of a bash script while it always worked when invoked directly from the shell.

At last I found a working solution here, this one even works with built-in commands bash offers:

<your command> & read -t <timeout in seconds> ; kill $!

For example running a “socat” UDP-listener on port 5555 for 10 seconds:

socat - udp4-listen:5555,reuseaddr,fork 2>/dev/null & read -t 10 ; kill $!

This solution has a nice side-effect: It works without creating a subshell process. This makes passing variables and re-directing in and out a lot easier.

Leave a Comment

Your email address will not be published. Required fields are marked *