Bash prompt (GIT & RVM)

gistfile1.sh

         RED="\[\033[0;31m\]"
      YELLOW="\[\033[0;33m\]"
       GREEN="\[\033[0;32m\]"
        BLUE="\[\033[0;34m\]"
   LIGHT_RED="\[\033[1;31m\]"
 LIGHT_GREEN="\[\033[1;32m\]"
       WHITE="\[\033[1;37m\]"
  LIGHT_GRAY="\[\033[0;37m\]"
      PURPLE="\[\033[0;35m\]"
        CYAN="\[\033[0;36m\]"
LIGHT_YELLOW="\[\033[1;33m\]"
  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}]*)"
  detached_branch_pattern="# Not currently on any branch"
  remote_pattern="# Your branch is (.*) of"
  diverge_pattern="# Your branch and (.*) have diverged"

  if [[ ${git_status}} =~ "Changes not staged for commit" ]]; then
    state="${RED}⚡"
  fi
  # add an else if or two here if you want to get more specific

  if [[ ${git_status} =~ ${remote_pattern} ]]; then
    if [[ ${BASH_REMATCH[1]} == "ahead" ]]; then
      remote="${RED}↑"
    else
      remote="${RED}↓"
    fi
  fi
  if [[ ${git_status} =~ ${diverge_pattern} ]]; then
    remote="${YELLOW}↕"
  fi

  if [[ ${git_status} =~ ${branch_pattern} ]]; then
    branch="${CYAN}${BASH_REMATCH[1]}"
  elif [[ ${git_status} =~ ${detached_branch_pattern} ]]; then
    branch="${CYAN}NO BRANCH"
  fi

  if [[ ${#branch} -gt "0" || ${#remote} -gt "0" ]]; then
    s1=" "
  fi
  if [[ ${#state} -gt "0" ]]; then
    s2=" "
  fi

  echo "${s1}${branch}${remote}${s2}${state}"
}

function parse_rvm_ruby_version {
  local gemset=$(echo $GEM_HOME | awk -F'@' '{print $2}')
  [ "$gemset" != "" ] && gemset="@$gemset"
  local version=$(echo $MY_RUBY_HOME | awk -F'-' '{print $2}')
  [ "$version" == "1.9.2" ] && version=""
  local full="$version$gemset"
  [ "$full" != "" ] && echo "$full "
}

function bash_prompt() {
  local UC=$BLUE              # user's color
  [ $UID -eq "0" ] && UC=$RED # root's color

  git_prompt="$(parse_git_branch)"

  prompt="$CYAN$(parse_rvm_ruby_version)$UC\u$BLUE@\h$COLOR_NONE:\w${git_prompt}${COLOR_NONE}"
  PS1="${prompt} $ "
}

PROMPT_COMMAND=bash_prompt

rvm tools identifier should be more reliable than parsing the environment :-)