I have an account on a network, and my shell is set to zsh, but when I log onto a computer that doesn't have zsh installed on it, a terminal I launch tries to run zsh and fails, so I get an empty terminal. I want to set my shell to something that will fall back to bash if zsh doesn't exist. I'd want to try something like:
zsh || bash
but I don't know how the shell I set in chsh is parsed, so I'm afraid I'll never be able to log in again if I set it to something wrong. What's the right setting for this?