A basic, but fast git prompt.

README.md

bash-basic-git-prompt

This is a considerably faster, but much more basic alternative to bash-git-prompt.

When adding this script to your .bash_profile or .bashrc, it'll display the selected branch of the current folder (if it's a git repo), and whether it's modified (yellow) or contains staged files (cyan).

The script makes the assumption, that a .git folder only exists when the directory is a git repo. Also, it checks for the english version of the git status command, so if you're using git in a different locale, make sure to adjust this.

bash-basic-git-prompt.sh

COLOR_GIT_CLEAN='\[\033[1;30m\]'
COLOR_GIT_MODIFIED='\[\033[0;33m\]'
COLOR_GIT_STAGED='\[\033[0;36m\]'
COLOR_RESET='\[\033[0m\]'

function git_prompt() {
  if [ -e ".git" ]; then
    branch_name=$(git symbolic-ref -q HEAD)
    branch_name=${branch_name##refs/heads/}
    branch_name=${branch_name:-HEAD}

    echo -n "→ "

    if [[ $(git status 2> /dev/null | tail -n1) = *"nothing to commit"* ]]; then
      echo -n "$COLOR_GIT_CLEAN$branch_name$COLOR_RESET"
    elif [[ $(git status 2> /dev/null | head -n5) = *"Changes to be committed"* ]]; then
      echo -n "$COLOR_GIT_STAGED$branch_name$COLOR_RESET"
    else
      echo -n "$COLOR_GIT_MODIFIED$branch_name*$COLOR_RESET"
    fi

    echo -n " "
  fi
}

function prompt() {
  PS1="\u@\h [ \w $(git_prompt)] \$ "
}

PROMPT_COMMAND=prompt

You always need to call git --porcelain or something like that to get the status information. So the only way to make it fast it to call git only once, and make sure that processing is as fast as possible.

I have written a very fast git-status in C++ with maximum optimizations. It even has a --refresh-sec parametr which will avoid extra calls to git if previous call was less than --refresh-sec seconds ago. I think this is the fastest possible way to do this.

It is for zsh, but you can adapt it to bash. And it is very fast: https://gitlab.com/cosurgi/zsh-git-cal-status-cpp

Posting entire solution would involve parsing the output of git status --porcelain --branch --git-dir ARG1 --work-tree ARG2. That's what this program does. Doing it in bash or any other interpreted language wouldn't be as fast.

Added you code to my own kubernetes and docker prompt:
https://colegatron.medium.com/bash-prompt-for-kubernetes-docker-and-git-a089a07eb3b2

For now this script only shows git prompt on root level of git repository. To change that you need to modify line 7:
if [ -e ".git" ]; then
to:
if git rev-parse --is-inside-work-tree > /dev/null 2>&1; then

You are absolutely right. I usually run all my stuff and scripts from the root of the projects, and didn't had to worry about, but your addition is very welcome.
Already updated the gist.
Thank you