My custom bash prompt

.prompt.bash

#!/bin/bash
#
# Scott Woods's custom bash prompt. 
#
# Load this file by adding the following to the bottom of your ~/.bashrc:
#
#     function prompt_command {
#         export PS1=$(~/.prompt.bash)
#     }
#     export PROMPT_COMMAND='export LAST_RETURN_VALUE=$? ; prompt_command'

Red='\[\e[0;31m\]'          
White='\[\e[0;37m\]'
Color_Off='\[\e[0m\]'

git_revision=$(git show 2> /dev/null | head -1 | awk '{ print substr($2,0,7) }')
if [ "$git_revision" ] ; then
  git_revision=" | ${git_revision}"

  if [ "$GIT_AUTHOR_NAME" ] ; then
    git_author=" | $GIT_AUTHOR_NAME"
  else
    git_author=""
  fi

  git_branch_ref=$(git symbolic-ref HEAD 2> /dev/null)
  if [ "$git_branch_ref" ] ; then
    git_branch=" | ${git_branch_ref#refs/heads/}"
  else
    git_branch=" | [none]"
  fi

  git_clean=$(git status | grep "working directory clean")
  if [ "$git_clean" ] ; then
    git_status=""
  else
    git_status="*"
  fi

  git_info="${git_author}${git_revision}${git_branch}${git_status}"
else 
  git_info=""
fi

if [[ $LAST_RETURN_VALUE -eq 0 ]] ; then
  dollar="\$"
else
  dollar="${Red}\$${Color_Off}"
fi

path="\w"

command_number="[\!]"

echo "\n${White}${path}${git_info}\n${command_number}${Color_Off} ${dollar} "