My bash prompt that probably came from Laurie or someone else at Last.fm

prompt.sh

# User specific aliases and functions

        RED="\[\033[31m\]"
     YELLOW="\[\033[0;33m\]"
 	  GREEN="\[\033[0;32m\]"
       BLUE="\[\033[0;34m\]"
 LIGHT_BLUE="\[\033[1;34m\]"
  LIGHT_RED="\[\033[1;31m\]"
LIGHT_GREEN="\[\033[1;32m\]"
      WHITE="\[\033[1;37m\]"
 LIGHT_GRAY="\[\033[0;37m\]"
 COLOR_NONE="\[\e[0m\]"

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_RED}⚡"
  fi
  # add an else if or two here if you want to get more specific
  if [[ ${git_status} =~ ${remote_pattern} ]]; then
    if [[ ${BASH_REMATCH[1]} == "ahead" ]]; then
      remote="${YELLOW}↑"
    else
      remote="${YELLOW}↓"
    fi
  fi
  if [[ ${git_status} =~ ${diverge_pattern} ]]; then
    remote="${YELLOW}↕"
  fi
  if [[ ${git_status} =~ ${branch_pattern} ]]; then
    branch=${BASH_REMATCH[1]}
    echo " (${branch})${remote}${state}"
  fi
}

function prompt_func() {
    previous_return_value=$?;
    # prompt="${TITLEBAR}$BLUE[$RED\w$GREEN$(__git_ps1)$YELLOW$(git_dirty_flag)$BLUE]$COLOR_NONE "
    prompt="${TITLEBAR}${LIGHT_BLUE}[${LIGHT_RED}\h:${WHITE}\w${GREEN}$(parse_git_branch)${LIGHT_BLUE}]${COLOR_NONE} "
    if test $previous_return_value -eq 0
    then
        PS1="${prompt}$ "
    else
        PS1="${prompt}${LIGHT_RED}$ ${COLOR_NONE}"
    fi
}

# This way you get the host/path in the title bar and the pretty PS1
PROMPT_COMMAND='prompt_func && echo -ne "\033]0;${USER}@${HOSTNAME}: ${PWD/$HOME/~}\007"'