bash_powerline

#!/usr/bin/env bash

# Borrowed and customized from https://github.com/riobard/bash-powerline

__powerline() {
  # Unicode symbols
  readonly PS_SYMBOL_DARWIN=''
  # readonly PS_SYMBOL_LINUX='$'
  readonly PS_SYMBOL_LINUX='🐧 '
  readonly PS_SYMBOL_OTHER='%'
  readonly GIT_BRANCH_SYMBOL='⑂'
  readonly GIT_BRANCH_CHANGED_SYMBOL='+'
  readonly GIT_NEED_PUSH_SYMBOL='⇡'
  readonly GIT_NEED_PULL_SYMBOL='⇣'
  readonly RUBY_SYMBOL='⬙'
  readonly NODE_SYMBOL='⬢'

  function __tput { tput $* 2> /dev/null; }

  # https://en.wikipedia.org/wiki/ANSI_escape_code#8-bit
  readonly FG_BLACK="\[$(__tput setaf 0)\]"
  readonly FG_WHITE="\[$(__tput setaf 7)\]"

  readonly FG_DARK_GRAY="\[$(__tput setaf 8)\]"
  readonly FG_GRAY="\[$(__tput setaf 15)\]"

  readonly FG_RED="\[$(__tput setaf 1)\]"
  readonly FG_GREEN="\[$(__tput setaf 2)\]"
  readonly FG_YELLOW="\[$(__tput setaf 3)\]"
  readonly FG_BLUE="\[$(__tput setaf 4)\]"
  readonly FG_MAGENTA="\[$(__tput setaf 5)\]"
  readonly FG_CYAN="\[$(__tput setaf 6)\]"

  readonly FG_HIGH_RED="\[$(__tput setaf 9)\]"
  readonly FG_HIGH_GREEN="\[$(__tput setaf 10)\]"
  readonly FG_HIGH_YELLOW="\[$(__tput setaf 11)\]"
  readonly FG_HIGH_BLUE="\[$(__tput setaf 12)\]"
  readonly FG_HIGH_MAGENTA="\[$(__tput setaf 13)\]"
  readonly FG_HIGH_CYAN="\[$(__tput setaf 14)\]"

  readonly BG_BLACK="\[$(__tput setab 0)\]"
  readonly BG_WHITE="\[$(__tput setab 7)\]"

  readonly BG_DARK_GRAY="\[$(__tput setab 8)\]"
  readonly BG_GRAY="\[$(__tput setab 15)\]"

  readonly BG_RED="\[$(__tput setab 1)\]"
  readonly BG_GREEN="\[$(__tput setab 2)\]"
  readonly BG_YELLOW="\[$(__tput setab 3)\]"
  readonly BG_BLUE="\[$(__tput setab 4)\]"
  readonly BG_MAGENTA="\[$(__tput setab 5)\]"
  readonly BG_CYAN="\[$(__tput setab 6)\]"

  readonly BG_HIGH_RED="\[$(__tput setab 9)\]"
  readonly BG_HIGH_GREEN="\[$(__tput setab 10)\]"
  readonly BG_HIGH_YELLOW="\[$(__tput setab 11)\]"
  readonly BG_HIGH_BLUE="\[$(__tput setab 12)\]"
  readonly BG_HIGH_MAGENTA="\[$(__tput setab 13)\]"
  readonly BG_HIGH_CYAN="\[$(__tput setab 14)\]"

  readonly BG_DEEP_GREEN="\[$(__tput setab 22)\]"
  readonly BG_DEEP_RED="\[$(__tput setab 88)\]"

  readonly DIM="\[$(__tput dim)\]"
  readonly REVERSE="\[$(__tput rev)\]"
  readonly RESET="\[$(__tput sgr0)\]"
  readonly BOLD="\[$(__tput bold)\]"

  # what OS?
  case "$(uname)" in
    Darwin)
      readonly PS_SYMBOL=$PS_SYMBOL_DARWIN
      ;;
    Linux)
      readonly PS_SYMBOL=$PS_SYMBOL_LINUX
      ;;
    *)
      readonly PS_SYMBOL=$PS_SYMBOL_OTHER
  esac

  ### Ruby #######################################################
  if [ `which rbenv 2> /dev/null` ]; then
    __ruby_version() { printf $(rbenv version-name); }
  elif [ `which ruby 2> /dev/null` ]; then
    __ruby_version() { printf $(ruby --version | cut -d' ' -f2); }
  else
    __ruby_version() { return; }
  fi

  __ruby_info() {
    local version=$(__ruby_version)
    [ -z "${version}" ] && return
    printf " $RUBY_SYMBOL ${version} "
  }

  ### Node.js ####################################################
  if [ `which nodenv 2> /dev/null` ]; then
    __node_version() { printf $(nodenv version-name); }
  elif [ `which node 2> /dev/null` ]; then
    __node_version() { printf $(node -v | cut -d'v' -f2); }
  else
    __node_version() { return; }
  fi

  __node_info() {
    local version=$(__node_version)
    [ -z "${version}" ] && return
    printf " $NODE_SYMBOL ${version} "
  }

  ### Git ########################################################
  __git_info() {
    [ -x "$(which git)" ] || return    # git not found

    local git_eng="env LANG=C git"   # force git output in English to make our work easier
    # get current branch name or short SHA1 hash for detached head
    local branch="$($git_eng symbolic-ref --short HEAD 2>/dev/null || $git_eng describe --tags --always 2>/dev/null)"
    [ -n "$branch" ] || return  # git branch not found

    local marks

    # branch is modified?
    [ -n "$($git_eng status --porcelain)" ] && marks+=" $GIT_BRANCH_CHANGED_SYMBOL"

    # how many commits local branch is ahead/behind of remote?
    local stat="$($git_eng status --porcelain --branch | grep '^##' | grep -o '\[.\+\]$')"
    local aheadN="$(echo $stat | grep -o 'ahead [[:digit:]]\+' | grep -o '[[:digit:]]\+')"
    local behindN="$(echo $stat | grep -o 'behind [[:digit:]]\+' | grep -o '[[:digit:]]\+')"
    [ -n "$aheadN" ] && marks+=" $GIT_NEED_PUSH_SYMBOL$aheadN"
    [ -n "$behindN" ] && marks+=" $GIT_NEED_PULL_SYMBOL$behindN"

    printf " $GIT_BRANCH_SYMBOL $branch$marks "
  }

  ### PROMPT #####################################################
  # __title_info() { echo -ne "${USER}@${HOSTNAME%%.*}:${PWD/$HOME/~}"; }
  __title_info() { echo -ne "${PWD##*/} : ${USER}@${HOSTNAME%%.*}"; }

  case $TERM in
    xterm*|rxvt|Eterm|eterm)
      title() { echo -ne "\033]2;$(__title_info)\007"; }
      ;;
    screen)
      title() { echo -ne "\033_$(__title_info)\033\\"; }
      ;;
  esac


  ps1() {
    # Check the exit code of the previous command and display different
    # colors in the prompt accordingly.
    if [ $? -eq 0 ]; then
      local BG_EXIT="$BG_DEEP_GREEN"
    else
      local BG_EXIT="$BG_DEEP_RED"
    fi

    PS1="\n$BG_DARK_GRAY$FG_GRAY \s $RESET"
    PS1+="$BG_HIGH_YELLOW$FG_BLACK \w $RESET"
    PS1+="$BG_HIGH_RED$FG_GRAY$(__ruby_info)$RESET"
    PS1+="$BG_DEEP_GREEN$FG_GRAY$(__node_info)$RESET"
    PS1+="$BG_HIGH_BLUE$FG_GRAY$(__git_info)$RESET\n"
    PS1+="$BG_GRAY$FG_BLACK \u@\h $RESET"
    PS1+="$BG_EXIT$FG_GRAY $PS_SYMBOL $RESET "
  }

  PROMPT_COMMAND="ps1 && title"
}

__powerline
unset __powerline