Intro

• Since macOS 10.15 (Catalina), zsh is a default shell in Terminal
• There are various configuration files such as .zshenv / .zshrc / .zlogin / .zprofile
• TLDR: Use .zshenv for things you need in non-interactive shells and .zshrc for things you need only in interactive shells

.zshenv

• .zshenv is sourced on all invocations of the shell, unless the -f option is set
• It should contain commands to set the command search path, plus other important environment variables
• .zshenv should not contain commands that produce output or assume the shell is attached to a tty

.zshrc

• .zshrc is sourced in interactive shells
• It should contain commands to set up aliases, functions, options, key bindings, etc.

.zlogin

• .zlogin is sourced in login shells
• It should contain commands that should be executed only in login shells
• .zlogin is not the place for alias definitions, options, environment variable settings, etc.

.zprofile

• .zprofile is similar to .zlogin, except that it is sourced before .zshrc
• .zprofile is meant as an alternative to .zlogin for ksh fans
• The two are not intended to be used together although this could certainly be done if desired