The exit code of a command in a Unix-based system is an important and easy-to-miss piece of data. It isn’t printed to standard out; you have to go looking for it. I find it useful to inspect this information when debugging or considering chaining unfamiliar commands.

A lot of people start programming with shared dotfiles, copied from a team or online. I did. Maybe you’re ready to move on; how would you do that?

Here’s a familiar scenario: you open a new terminal, and before the prompt appears, you see the following.

You have new mail.

What’s going on here?

My current favorite command line alias is mgrim, composed of four other aliases. Here’s what it is, and what it does.