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.

How the true and false commands work, and how to put them to use on the command line and in scripts. True and false are common concepts in all forms of computing. They’re critical to Boolean logic ...

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 ...

ITworld.com – Some of the worst-written scripts that I have encountered perform some action on behalf of the person running the script and then blithely continue on without ever checking whether the ...