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 ...

This post follows up on Part 1 by examining the many ways that you can test the value of variables – e.g., whether they equal particular strings like “yes” or “no”, if they have a numeric value, if ...

The shell does far more than run commands. Here’s how Bash expands your input behind the scenes so you can write cleaner, ...