Each Linux command returns an exit code, with 0 indicating success and non-zero values indicating failure. You can use the $? variable to access the exit code and control program flow in scripts. Be ...

There are quite a few exit codes used on Linux systems, though no listing you can display when you’re feeling curious. In fact, you won’t see the numeric codes unless you specifically ask for them.

Last month, we looked at signals, the rudimentary mechanism that processes on a Linux box can use to communicate events and state changes. We talked about how each of the signals can be sent manually ...