To get Git-prompt work in Zsh without a bug in a function

Question

This question is based on the thread.

I have the following Git-prompt at the moment. I get the following warning after cding to a non-Git folder.

fatal: Not a git repository (or any of the parent directories): .git                   
fatal: git diff [--no-index] takes two paths
fatal: Not a git repository (or any of the parent directories): .git
fatal: git diff [--no-index] takes two paths

My current code for Git-prompt in Zsh

 # get the name of the branch we are on
 git_prompt_info() {
     ref=$(git symbolic-ref HEAD | cut -d'/' -f3)
     echo $ref
 }
 get_git_dirty() {
   git diff --quiet || echo '*'                                                   
 }
 autoload -U colors
 colors
 setopt prompt_subst
 PROMPT='%{$fg[blue]%}%c %{$fg_bold[red]%}$(git_prompt_info)$(get_git_dirty)%{$fg[blue]%} $ %{$reset_color%}'

The problem is the following code which causes the warning for non-Git folders

get_git_dirty() {
       git diff --quiet || echo '*'                                                   
     }

I tried to solve the bug by redirecting errors to /tmp/ unsuccessfully such that

  get_git_dirty() {
           git diff --quiet 2>/tmp/error || echo '*' 2>/tmp/error                                                   
   }

How can you get rid of the warning messages for non-git directories?

Answer 1

Would something like this work?

get_git_dirty() {
set __MT_OK__=0

if [[ -d .git ]]; then
    __MT_OK__=1
fi

while [[ ! -d .git ]]; do
    cd ..
    if [[ -d .git ]]; then
     __MT_OK__=1
     break
    fi
    if [[ $PWD = "/" ]]; then
     break
    fi
done



if [[ __MT_OK__ -eq 1 ]]; then
           git diff --quiet || echo '*'                                                    
fi
}

This may not be the most elegant solution, but it should work.

Answer 2

Actually, I think it's the first one that's causing the error because when I run it in a non-git directory, I get the errors. The second one doesn't spit out the errors.

You could redirect the error output to /dev/null.

This would work in bash, not sure about zsh but it should give you an idea of how to go.

git_prompt_info() {
    ref=$(git symbolic-ref HEAD 2>/dev/null)
    if [ ! -z $ref ]; then
        newref=$(echo $ref | cut -d'/' -f3)
        echo $newref
    fi
}

I don't know what would be more expensive though, running git or traversing all the directories until you find a .git directory. Git probably does the directory traversal anyways. Not sure.

Answer 3

Use

REL=$(git rev-parse --show-prefix 2>/dev/null) || { echo "$@" ; exit ; }

or

BR=$(git symbolic-ref HEAD 2>/dev/null) || { echo "$@" ; exit ; }

Exit early.

To be more explicit: you can't use exit status of git diff --quiet to check whether you are in working repository because git diff then "exits with 1 if there were differences and 0 means no differences." (see git-diff manpage)

Answer 4

I get this code finally to work:

 # get the name of the branch we are on
 git_prompt_info() {
     BR=$(git symbolic-ref HEAD 2>/dev/null | awk -F/ '{ print $3 }') || { echo "$@" ; exit ; }
     echo $BR
 }

while the rest are the same as before.