Bash $ps1

.bash_functions

#!/bin/bash

# Helper functions for color prompts
# You can specify common colors by name (see case
# statement below), 8-bit colors by decimal value,
# and (where available) TrueColor 24-bit colors
# as semicolon delimited decimals.
#
# With no arguments, resets the color to default.
#
# The second argument can set formatting, such as bold,
# dim, and invert. Use default as the color to just
# apply formatting.
#
# http://tldp.org/HOWTO/Bash-Prompt-HOWTO/x329.html
# http://misc.flogisoft.com/bash/tip_colors_and_formatting
# http://unix.stackexchange.com/a/124409/19157
# https://gist.github.com/XVilka/8346728
function color() {
  local color format code attr
  color=$(echo "$1" | tr '[:upper:]' '[:lower:]')
  format=$(echo "$2" | tr '[:upper:]' '[:lower:]')
  case ${color//;/,} in # case doesn't seem to match semicolons
    black)      code=30 ;;
    dgrey)      code=90 ;;
    red)        code=31 ;;
    lred)       code=91 ;;
    green)      code=32 ;;
    lgreen)     code=92 ;;
    yellow)     code=33 ;;
    lyellow)    code=93 ;;
    blue)       code=34 ;;
    lblue)      code=94 ;;
    purple)     code=35 ;;
    lpurple)    code=95 ;;
    cyan)       code=36 ;;
    lcyan)      code=96 ;;
    grey|lgrey) code=37 ;;
    white)      code=97 ;;
    d|default)  code=39 ;;
    *[0-9],*)   code="38;2;$color" ;;
    *[0-9]*)    code="38;5;$color" ;;
    ''|none)    code=0 ;; # reset
    *) echo "Invalid color $1" >&2 && return 1 ;;
  esac
  # TODO support multiple formattings, like BOLD UNDERLINE
  case $format in
    bold|bright) attr=1 ;;
    dim) attr=2 ;;
    italic) attr=3 ;; # limited support
    underline) attr=4 ;;
    blink) attr=5 ;; # you monster
    reverse) attr=7 ;;
    hide|hidden) attr=8 ;;
    strike) attr=9 ;; # limited support
    '') : ;; # no formatting
    *) echo "Invalid format $2" >&2 && return 1 ;;
  esac

  printf '\033[%s%sm' "${attr:+$attr;}" "${code}"
}

# Wraps the color function in escaped square brackets,
# which is necessary in prompts (PS1, etc.) to tell
# bash the escape characters are non-printing.
function pcolor() {
  # TODO \001...\002 doesn't appear to work on Ubuntu
  #printf '\001%s\002' "$(color "$@")"
  printf '\[%s\]' "$(color "$@")"
}

export -f color
export -f pcolor

.bash_prompt

# get current branch in git repo
function parse_git_branch() {
	BRANCH=$(git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/\1/')
	if [ ! "${BRANCH}" == "" ]
	then
		STAT=$(parse_git_dirty)
		echo "  ${BRANCH}${STAT}"
	else
		echo ""
	fi
}

# get current status of git repo
function parse_git_dirty {
	status=$(git status 2>&1 | tee)
	dirty=$(echo -n "${status}" 2> /dev/null | grep "modified:" &> /dev/null; echo "$?")
	up_to_date=$(echo -n "${status}" 2> /dev/null | grep "working tree clean" &> /dev/null; echo "$?")
	behind=$(echo -n "${status}" 2> /dev/null | grep "Your branch is behind" &> /dev/null; echo "$?")
	ahead=$(echo -n "${status}" 2> /dev/null | grep "Your branch is ahead of" &> /dev/null; echo "$?")
	parts=''

	if [ "${dirty}" == "0" ]; then
		parts="${parts}*"
	fi

	if [ "${behind}" == "0" ]; then
		parts="${parts} $(color 'BLUE')$(color)"
	fi
	if [ "${ahead}" == "0" ]; then
		parts="${parts} $(color 'BLUE')$(color)"
	fi
	#if [ "${up_to_date}" == "0" ]; then
		#parts="${parts} "
	#fi
	if [ ! "${parts}" == "" ]; then
		echo -e "${parts}"
	else
		echo ""
	fi
}

updateps1() {
  local exit_code=$?
  local has_jobs=$(jobs | wc -l) 
  ps1sub() {
    local chevron_color=''
    if [ "$exit_code" == "0" ]; then
      if (( $has_jobs > 0 )); then
        chevron_color='PURPLE'
      else
        chevron_color='D'
      fi
    else
      chevron_color='RED'
    fi 
    printf "$(pcolor 'LCYAN')\w$(pcolor 'DGREY')\`parse_git_branch\`\\n$(pcolor $chevron_color)❯$(pcolor) "
  }
  PS1="$(ps1sub)"
}
PROMPT_COMMAND='updateps1'