Terminal programs have a lot of hidden rules and conventions (like some programs don’t quit when you press Ctrl+C!), and knowing them makes your life WAY easier.

Here are some of the questions I ask myself when starting a program!

• is it a REPL? (Ctrl+D probably quits) (I can probably use basic readline shortcuts) -> is it using canonical mode? (arrow keys don’t work when entering text, try rlwrap)

• am I actually in another program it started? (A pager like less or a text editor like vim)

• is it noninteractive? (quit with Ctrl+C) -> is it stuck because it’s waiting for input on stdin and I forgot to pipe to it?

• is it a shell? -> is this a minimal shell like dash? (if so, can I use bash instead?)

• is it full screen? (q might quit) -> mouse reporting: is it on? -> (selecting text doesn’t work, but you might be able to click to navigate)

• am I in some kind of special environment? -> (a server? tmux/screen? a container? a virtualenv? what environment variables are set?)