bash-it mbriggs change to add virtualenv

mbriggs.theme.bash

# ------------------------------------------------------------------#
#          FILE: mbriggs.zsh-theme                                  #
#            BY: Matt Briggs (matt@mattbriggs.net)                  #
#      BASED ON: smt by Stephen Tudor (stephen@tudorstudio.com)     #
# ------------------------------------------------------------------#

SCM_THEME_PROMPT_DIRTY="${red}⚡${reset_color}"
SCM_THEME_PROMPT_AHEAD="${red}!${reset_color}"
SCM_THEME_PROMPT_CLEAN="${green}✓${reset_color}"
SCM_THEME_PROMPT_PREFIX=" "
SCM_THEME_PROMPT_SUFFIX=""
GIT_SHA_PREFIX=" ${yellow}"
GIT_SHA_SUFFIX="${reset_color}"
SCM_GIT_CHAR='${bold_cyan}±${normal}'
SCM_SVN_CHAR='${bold_cyan}⑆${normal}'
SCM_HG_CHAR='${bold_red}☿${normal}'

function virtualenv_prompt() {
  if [ ! -z "$VIRTUAL_ENV" ]
  then
    local env=$(dirname $VIRTUAL_ENV)
    echo "(${env##*/})"
  fi
}

function git_short_sha() {
  SHA=$(git rev-parse --short HEAD 2> /dev/null) && echo "$GIT_SHA_PREFIX$SHA$GIT_SHA_SUFFIX"
}

function prompt() {
    local return_status=""
    local ruby="${red}$(ruby_version_prompt)${reset_color}"
    local user_host="${green}\h${reset_color}"
    local current_path="\w"
    local n_commands="\!"
    local git_branch="$(git_short_sha)$(scm_prompt_info)"
    local prompt_symbol='λ'
    local env="${bold_white}$(virtualenv_prompt)${reset_color}"
    local open='| '
    local close=' |'
    local prompt_char=' \$ '

    PS1="\n${n_commands} ${user_host} ${prompt_symbol} ${ruby} ${open}${current_path} ${env}${git_branch}${close}${return_status}\n${prompt_char}"
}

PROMPT_COMMAND=prompt