How to reset my terminal prompt to default - post mess-up
So you're using zsh now not bash?

The following applies to zsh:

To make your change persistent you have to include the export PS1 line in your ~/.zshrc file. If you already have such a file, open it and check for an export PS1 line and edit it to suit your needs. 

If not, run:

echo 'export PS1="%M $ "' &gt;&gt; ~/.zshrc


which will change your prompt to include the full machine host name followed by $ as requested (see here for more details).

To see the effects of this change you either need to open a new terminal window or source the .zshrc file (in every terminal that was open when you made the change):

source ~/.zshrc


You can achieve the same results in bash but using either the ~/.bash_profile or ~/.bashrc files (and not forgetting to source them).



A little aside:

I'm sure you've done your research by now but if you get stuck in vim again, the following key combination will help: ESC : q &lt;CR&gt; (where &lt;CR&gt; is the enter key). If you've made changes though this won't work. You can either discard the changes:

ESC : q! &lt;CR&gt;


or write the changes to file:

ESC : wq &lt;CR&gt;


If your experience didn't scare you off from vim, here's a great cheat sheet I'd recommend: https://vim.rtorr.com/