created git-prompt.sh

USAGE

  export PROMPT_COMMAND='export PS1="<your existing prompt>$(git_prompt)"'

The git_prompt function will return a string showing the current branch name
as well as how ahead/behind it is from its origin (since the last fetch).
It will also show (via asterisk after the branch name) whether the working
directory is dirty or not. Finally, if you are on a detached HEAD, it will
attempt to show the tag, or the SHA-1 if the HEAD is not tagged.

git_prompt will return an empty string if you are not in a git-managed
directory (i.e. if the 'git status' command would fail).

EXAMPLES

  [master]

  This means that you are currently on the master branch in this git-managed
  directory, that you are neither ahead nor behind from master's origin,
  and that you have no changes in your working directory.

  [master*]

  This means that you are currently on the master branch in this git-managed
  directory, that you are neither ahead nor behind from master's origin,
  and that you do have changes in your working directory that are uncommited.

  [3 -> foo]

  This means that you are currently on the foo branch, it is 3 ahead of its
  origin (i.e. you can push it) that there are no changes in the working
  directory.

  [bar* -> 2]

  This means that you are currently on the bar branch, it is 2 behind of its
  origin (i.e. you can fast-forward it) that there are indeed changes in the
  working directory.

  [3 -> foobar* -> 2]

  This means that the foobar branch is 3 commits ahead and 2 commits behind
  of its origin (i.e. its diverged), and that there are changes in the
  working directory.

  [detached(1.1.3)]

  This means that you are currently in detached HEAD mode, and HEAD points
  to tag 1.1.3.

  [detached(1aaf71b)]

  This means that you are currently in detached HEAD mode, and HEAD is at
  commit 1aaf71b, which is not tagged.