Permanently change zsh environment variable on macOS Big Sur? [closed]

Question

I tried to customize the ZSH terminal shell (e.g. prompt, auto-completion behavior) by editing the ZSH files, but failed. I have tried both the following, and none worked:

1. Edit ~/.zshrc:
   
   When I tried to edit the (blank) file (even under the sudo command), I got the following error message: ".zshrc" E166: Can't open linked file for writing (similar problem happens when trying on .zshenv.
2. Edit /etc/zshrc:
   
   This worked, until the computer restarted and resets the file.

What is the correct way to deal with this?

_{N.B.: I'm running macOS Big Sur 11.6.}

Answer 1

Undo whatever changes you made to /etc/zshrc, then forget that this file exists. You should be leaving that file alone.

Put your changes in $HOME/.zshrc. This will usually work, zsh should read that file on startup whenever the shell is an interactive one (see man zsh). Note that zsh reads that file regardless of whether or not it is a login shell, so it will be interpreted on every shell invocation.

Forget that sudo exists.