Functions for git in bash / zsh prompt

gitprompt

# To use gitprompt to set your prompt to include a colored git branch label:
# bash:
#   source gitprompt
#   bash_colors
#   PS1='[\[$(git_branch_color)\]$(parse_git_branch)\[${NORMAL}\]] '"$PS1"
# zsh:
#   source gitprompt
#   zsh_colors
#   setopt PROMPT_SUBST
#   export PROMPT='[%F{$(git_branch_color)}$(parse_git_branch)%f] %B%F{240}%~%f %# '

bash_colors() {
  export BLACK=$(tput setaf 0)
  export RED=$(tput setaf 1)
  export GREEN=$(tput setaf 2)
  export YELLOW=$(tput setaf 3)
  export BLUE=$(tput setaf 4)
  export MAGENTA=$(tput setaf 5)
  export CYAN=$(tput setaf 6)
  export WHITE=$(tput setaf 7)
  export NORMAL=$(tput sgr0)
}

zsh_colors() {
  export BLACK='black'
  export RED='red'
  export GREEN='green'
  export YELLOW='yellow'
  export BLUE='blue'
  export MAGENTA='magenta'
  export CYAN='cyan'
  export WHITE='white'
  export NORMAL='default'
}

parse_git_branch () {
  if git rev-parse --git-dir >/dev/null 2>&1; then
    gitver=$(git branch 2>/dev/null| sed -n '/^\*/s/^\* //p')
  else
    gitver='none'
  fi
  echo -e $gitver
}

git_branch_status () {
  if ! git rev-parse --git-dir >/dev/null 2>&1 ; then
    echo none
    return 0
  fi

  firstline=1
  gitstatus=clean

  while read line; do
    if [ $firstline -eq 1 ]; then
      # Read first line to determine if we are ahead or behind remote
      firstline=0
      if [[ $line =~ '\[ahead .+\]' ]]; then gitstatus=ahead; fi
      if [[ $line =~ '\[.*behind .+\]' ]]; then gitstatus=behind; fi
    else
      # Read sceond line: anything here means there's a modified or added file
      [ -n "$line" ] && gitstatus=dirty
    fi
  done < <(git status -sb | head -2)

  echo -ne $gitstatus
}

git_branch_color () {
  case "$(git_branch_status)" in
  dirty)
    echo "$RED"
    ;;
  ahead)
    echo "$CYAN"
    ;;
  behind)
    echo "$YELLOW"
    ;;
  clean)
    echo "$GREEN"
    ;;
  none)
    echo "$NORMAL"
    ;;
  *)
    echo "$NORMAL"
    echo "gitprompt error: unrecognized status $(git_branch_status)" >&2
    ;;
  esac
}