Startup files for shells

Each time you open the command line (aka the command prompt, the terminal, and a billion other names), it runs a few commands to set itself up.

This setup usually involves setting the PATH up so it knows where to find software, asking pyenv what the default Python should be, and a handful of other tasks. It isn’t a fancy process, but it’s necessary!

Depending on which shell you use, you’ll have a different set of startup files.

bash uses .bash_profile and .bashrc
zsh uses .zprofile and .zshrc

Sometimes when you’re setting up software, you’ll see mentions of these kinds of files:

echo 'export PYENV_ROOT="$HOME/.pyenv"' >> ~/.zshrc
echo 'export PATH="$PYENV_ROOT/bin:$PATH"' >> ~/.zshrc
echo -e 'if command -v pyenv 1>/dev/null 2>&1; then\n  eval "$(pyenv init --path)"\nfi' >> ~/.zshrc

If you ignore everything that you don’t understand (which is most of it), you can probably guess that the code is doing something to .zshrc to help set up pyenv every time you start up a new shell. And you’d be right!

It’s asking to edit .zshrc instead of .bash_profile because you’re probably using a newer mac that has zsh instead of bash!

Notice there are two setup files for each shell! One includes the word profile and the other rc. Okay, now forget about that forever. There’s no real difference between them, and they both get run.

You can easily edit these files in Visual Studio Code.

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