Logging shell scripts' executions

Source

Small hack. Do you have a bash1 script that runs via cron or incron or any other daemon, and you wanna debug it by at least tracing its execution? Well, simply surround it by:

(

set -x

...

) > /tmp/$0-$(date +%F.%T).log

But! Do not make the same mistake I did and forget to redirect stderr too2!:

) > /tmp/$0-$(date +%F.%T).log 2>&1

I know there is a shortcut for that, but I'm too lazy to look it up.

  1. I'm not sure this works in sh. ↩

  2. Othewise the trace does not appear in the log, because it's output to stderr. ↩