How to trap exit code in Bash script

Question

There're many exit points in my bash code. I need to do some clean up work on exit, so I used trap to add a callback for exit like this:

trap "mycleanup" EXIT 

The problem is there're different exit codes, I need to do corresponding cleanup works. Can I get exit code in mycleanup?

Answer 1

The accepted answer is basically correct, I just want to clarify things.

The following example works well:

#!/bin/bash  cleanup() {     rv=$?     rm -rf "$tmpdir"     exit $rv }  tmpdir="$(mktemp)" trap "cleanup" EXIT # Do things... 

But you have to be more careful if doing cleanup inline, without a function. For example this won't work:

trap "rv=$?; rm -rf $tmpdir; exit $rv" EXIT 

Instead you have to escape the $rv and $? variables:

trap "rv=\$?; rm -rf $tmpdir; exit \$rv" EXIT 

You might also want to escape $tmpdir, as it will get evaluated when the trap line gets executed and if the tmpdir value changes later that might not give the expected behaviour.

Edit: Use shellcheck to check your bash scripts and be aware of problems like this.