Add git information to bash prompt

gistfile1.sh

# Bedazzle terminal with Git branch information
NO_COLOR="\[\033[0m\]"
BLACK="\[\033[0;30m\]"
RED="\[\033[0;31m\]"
GREEN="\[\033[0;32m\]"
YELLOW="\[\033[0;33m\]"
BLUE="\[\033[0;34m\]"
PURPLE="\[\033[0;35m\]"
CYAN="\[\033[0;36m\]"
GRAY="\[\033[0;90m\]"
LIGHT_GRAY="\[\033[0;37m\]"
LIGHT_RED="\[\033[0;91m\]"
LIGHT_GREEN="\[\033[0;92m\]"
LIGHT_YELLOW="\[\033[0;93m\]"
LIGHT_BLUE="\[\033[0;94m\]"
LIGHT_PURPLE="\[\033[0;95m\]"
LIGHT_CYAN="\[\033[0;96m\]"
WHITE="\[\033[0;97m\]"


function parse_git_branch {

  git rev-parse --git-dir &> /dev/null
  git_status="$(git status 2> /dev/null)"
  branch_pattern="^# On branch ([^${IFS}]*)"
  remote_pattern="# Your branch is (.*) of"
  diverge_pattern="# Your branch and (.*) have diverged"
  if [[ ! ${git_status} =~ "working directory clean" ]]; then
    state="${LIGHT_PURPLE}⚡"
  fi
  # add an else if or two here if you want to get more specific
  if [[ ${git_status} =~ ${remote_pattern} ]]; then
    if [[ ${BASH_REMATCH[1]} == "ahead" ]]; then
      remote="${LIGHT_YELLOW}↑"
    else
      remote="${LIGHT_YELLOW}↓"
    fi
  fi
  if [[ ${git_status} =~ ${diverge_pattern} ]]; then
    remote="${LIGHT_YELLOW}↕"
  fi
  if [[ ${git_status} =~ ${branch_pattern} ]]; then
    branch=${BASH_REMATCH[1]}
    echo " (${branch})${remote}${state}"
  fi
}

function prompt_func() {
    previous_return_value=$?;
    prompt="${NO_COLOR}${NO_COLOR}\W${GRAY}$(parse_git_branch)${NO_COLOR}"
    if test $previous_return_value -eq 0
    then
        PS1="${prompt}${GREEN} $ ${NO_COLOR}"
    else
        PS1="${prompt}${RED} $ ${NO_COLOR}"
    fi
}

PROMPT_COMMAND=prompt_func