Here’s a fun survey question: name as many two-character Unix commands as you can and say what they do.
Let’s be precise about what we mean by a “command”:
- Shell aliases like
laare not commands.
- Shell built-in commands count as commands; over time the shell incorporated directly things that were previously separate executables in Unix.
- Commands not available in a wide variety of Unix distributions by default don’t count. In other words, if you have to install some optional package to get the command then it isn’t a “Unix” command.
- Optional: Only allow commands included in a “classic” Unix from Bell Labs.
Ready? Let’s go.