How can I make vim only write to file after buffer has been modified?

Question

I have this function which sources my .zshrc only if it has been modified in vim but I recently reinstalled Windows and WSL and then used my old .zshrc and .vimrc to get my setup back but this specific function doesn't work like it did before:

function zshrc () {
    local original_ctime="$(zstat +ctime -- ~/.zshrc)" 2>/dev/null
    vim ~/.zshrc || return
    [[ -n $original_ctime ]] || return
    if [[ $original_ctime != "$(zstat +ctime -- ~/.zshrc 2>/dev/null)" ]]
    then
        source ~/.zshrc
    fi
}

This function is supposed to check if the file creation time has changed. See here.

Before I reinstalled WSL I could run zshrc and save the vim buffer using :wq (without making any changes) and then vim would not overwrite the original file so it WON'T source ~/.zshrc and if I DO make changes then only vim will overwrite the original file, so the function WILL source ~/.zshrc. I'm assuming some defaults were maybe changed in vim so how can I get that specific behaviour back?

I understand that I can just exit vim with :q! to get this but when I'm editing different files quickly then I'll use :wq without thinking about it and then it sources .zshrc again without any changes.

Answer 1

Get in the habit of doing Z Z (i.e., Shift+Z, Shift+Z).  If the buffer has been modified, this will do :wq.  If the buffer hasn't been modified, it will simply exit without saving.