bashrc-gitinc.sh

#!/bin/bash
# Author: John Wolfe <bjw@onwav.com>
# Last Modified: Mar 24, 2011. 18:20 CDT
# License: zlib/libpng
# Declare git_ps1 and normal_ps1 in your bashrc or this file, set PROMPT_COMMAND='dotgitinvestigate >/dev/null 2>&1' in your bashrc.
# Be sure to use single quotes in the declaration of your ps1s, so the variables get evaluated in this file rather than at the time of declaration.
# Example git_ps1='[\[${bldblu}\]\u\[${txtwht}\]@\[${bldwht}\]\h\[${txtrst}\]:\[${txtpur}\]\W\[${txtrst}\]\[${txtgrn}\]($branch:${treeish:0:5})\[${txtrst}\]]$ '
# Example normal_ps1='[\[${bldblu}\]\u\[${txtwht}\]@\[${bldwht}\]\h\[${txtrst}\]:\[${txtpur}\]\W\[${txtrst}\]]$ '
# For the shell color variables in previous examples, include: https://gist.github.com/886087 in this file (or your bashrc) with ". /path/to/bashrc-colors.sh"

pwdln() {

   # Doing PE from the beginning of the string is needed
   # so we get a string of 0 len to break the until loop.

   pwdmod="${PWD}/"
   itr=0
   until [[ -z "$pwdmod" ]];do
      itr=$(($itr+1))
      pwdmod="${pwdmod#*/}"
   done
   echo -n $(($itr-1))

}

dotgitinvestigate() {

   # Ghetto var scoping, we don't want to keep git_dir if it didn't get declared this run
   unset -v git_dir

   # If there is a git dir in the cwd, great, we're done.
   if [[ -d "${PWD}/.git" ]];then
      git_dir="${PWD}/.git"
   else
      pwdmod2="${PWD}"                                     #  Since we didn't find a $PWD/.git, we're going to pop
      for (( i=2; i<=$(pwdln); i++ ));do                   #  a directory off the end of the $pwdmod2 stack until we
         pwdmod2="${pwdmod2%/*}"                           #  come across a ./.git. /home/igneous/proj/1 will start at
         if [[ -d "${pwdmod2}/.git" ]];then                #  /home/igneous/proj because of our loop starting at 2.
            git_dir="${pwdmod2}/.git"
         fi
      done
   fi

   chkgitbranch

}

chkgitbranch() {

   # More ghetto scoping.
   unset -v branch ref treeish

   if [[ -f "${git_dir}/rebase-apply/head-name" ]];then
      read branch < "${git_dir}/rebase-apply/head-name"
      read treeish < "${git_dir}/rebase-apply/original-commit"
      branch="${branch##*/}-REBASE"
      eval "PS1=\"$git_ps1\""
   elif [[ -f "${git_dir}/rebase-merge/head-name" ]];then
      read branch < "${git_dir}/rebase-merge/head-name"
      read treeish < "${git_dir}/rebase-merge/stopped-sha"
      branch="${branch##*/}-REBASE"
      eval "PS1=\"$git_ps1\""
   elif [[ "$git_dir" ]];then
      read branch < "${git_dir}/HEAD"                      # Read the file
      ref="${branch#ref: *}"                               # Let's declare $ref before we nuke $branch
      branch="${branch##*/}"                               # We only care about the end of the file path here "refs/heads/master" -> "master".
      read treeish < "${git_dir}/$ref" || treeish="INIT?"  # git_dir ( ~/project ) + ref ( refs/heads/master ) == ~/project/refs/heads/master
      eval "PS1=\"$git_ps1\""                              # And if the git ref directory doesn't exist, we assume it's a new repo.
   else
      eval "PS1=\"$normal_ps1\""
   fi

}