S99_git

setopt prompt_subst

chpwd_functions=('__set_current_git_branch' ${chpwd_functions:#__set_current_git_branch})
preexec_functions=('__force_update_git_vars' ${precmd_functions:#__force_update_git_vars})
precmd_functions=('__update_git_vars' ${precmd_functions:#__update_git_vars})

function __force_update_git_vars() {
  case "$1" in
  *git*)
    # delay setting prompt until next precmd hook
    export __update_git_vars=1
    ;;
  esac
}

function __update_git_vars() {
  if test -n "$__update_git_vars"; then
    __set_current_git_branch
    unset __update_git_vars
  fi
}

function __set_current_git_branch() {
  export __CURRENT_GIT_BRANCH="$(git branch --no-color 2>/dev/null | sed -n 's/^\* \(.*\)/\1/p')"
}

function __git_prompt_info() {
  if [ -n "$__CURRENT_GIT_BRANCH" ]; then
    printf "$1" "$__CURRENT_GIT_BRANCH"
  fi
}

export __update_git_vars=1
#export PROMPT='%n@%m:%c$(__git_prompt_info " [%s]")%# '