I have set -e turned on for my script. The only thing is there is one command here that I don't want causing the script to exit if it fails, but I want everything else to do that. How can I keep set -e on, and not have my script exit when an error code is thrown?
script in question:
native=$(pacman -Qenq -) If stdin has a non-native package name an error code gets written to stdin.
set -e aka set -o errexit doesn't apply to commands that are parts of conditions like in:
if cmd; do until cmd; do while cmd; do cmd || whatever cmd && whatever That also applies to the ERR trap for shells supporting it.
So, an idiomatic way to ignore the failure of a command is with:
cmd || : errors ignored Or just:
cmd || true cmd || : That cancels set -e for that cmd invocation and also sets $? to 0 (to that of :/true when cmd fails)
cmd && true ret=$? Also cancels set -e but preserves the exit status of cmd.
$? between cmd || true and cmd || :? cmd || :, $? is 0. After cmd && :, $? is the exit status of cmd. > var= > : ${var:=foo} > echo "$var" foo 
: command.
pacman -Qenq -is run withstdinholding a foreign packagenativeends up being unset.-xoutput shows it being set (to an empty string, but set).set -eturned on for the script.