bash prompt with git status

git-shell.sh

RED="\[\033[0;31m\]"
YELLOW="\[\033[0;33m\]"
GREEN="\[\033[0;32m\]"
WHITE="\[\033[1;37m\]"

function parse_git_branch {
   ref=$(git symbolic-ref HEAD 2> /dev/null) || return
   foo=${ref#refs/heads/}
   status=$(git status -s | awk '{print $1}' 2>&1)
   echo "$status" | grep M > /dev/null 2>&1
   changes=$?

   echo "$status" | grep '??' > /dev/null 2>&1
   newFiles=$?

   echo "$status" | grep 'D' > /dev/null 2>&1
   delFiles=$?

   if [ $changes = 0 ]
   then
     foo="$foo*"
   fi

   if [ $newFiles = 0 ]
   then
     foo="$foo+"
   fi

   if [ $delFiles = 0 ]
   then
     foo="$foo-"
   fi

   echo "($foo)"
}


PS1="$WHITE[$GREEN\u@\h:\w$WHITE]$YELLOW\$(parse_git_branch)$GREEN\$ "

largely stolen from http://www.railstips.org/blog/archives/2009/02/02/bedazzle-your-bash-prompt-with-git-info/