Simple Bash tool, displaying current branch, in the current Git repository

prompt_show_branch.bash

#!/bin/bash

export SHOW_BRANCH=yes

function git_working_status {
  if [[ `git status 2> /dev/null` != "" && `echo $SHOW_BRANCH` == "yes" ]]
  then
    current_branch=`LANG=en_US.UTF-8 LANGUAGE=en_US:en git status 2> /dev/null | head -1 | cut -d ' ' -f3`
    current_unt_status=`LANG=en_US.UTF-8 LANGUAGE=en_US:en git status | egrep -i "untracked files|changes not staged"`
    current_add_status=`LANG=en_US.UTF-8 LANGUAGE=en_US:en git status | egrep -i "changes to be committed"`
    current_log_status=`LANG=en_US.UTF-8 LANGUAGE=en_US:en git log origin/$current_branch.. 2> /dev/null`
    current_diff=`LANG=en_US.UTF-8 LANGUAGE=en_US:en git diff origin/$current_branch 2>&1`
    color="\001\033[92m\002"
    if   [[ $current_diff =~ "fatal" ]]; then local="\001\033[96m\002local\001\033[0m\002/"; fi
    if   [[ -n $current_unt_status   ]]; then color="\001\033[31m\002"                    # repository modif:   [branch name in RED]
    elif [[ -n $current_add_status   ]]; then color="\001\033[33m\002"                    # files added to git: [branch name in YELLOW]
    elif [[ -n $current_log_status   ]]; then color="\001\033[93;1m\002*\001\033[92m\002" # files commited:     [YELLOW star + branch name in LIGHT GREEN]
    fi

    status="[\u2387  ${local}${color}${current_branch}\001\033[0m\002]"
    echo -en "$status" > /tmp/git_status.txt
    echo -en "$status"
    # TODO: detect if branch is up to date (compare with remote branch)
    # TODO: detect deleted remote branch
  fi
}

if [ "$color_prompt" = yes ]; then
    PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[0m\]`git_working_status`\$ '
else
    PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\[`git_working_status`\]\$ '
fi

unset color_prompt force_color_prompt

You can paste this code in a ~/.prompt_show_branch file

Then, in your ~/.bashrc, remove or comment the default PS1 setting, and source the ~/.prompt_show_branch file

#if [ "$color_prompt" = yes ]; then
#    PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
#else
#    PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
#fi
#unset color_prompt force_color_prompt

PROMPT_SHOW_BRANCH_FILE="$HOME/.prompt_show_branch"
[[ -f $PROMPT_SHOW_BRANCH_FILE ]] && source $PROMPT_SHOW_BRANCH_FILE