[2010-01] an old (shitty?) PS1 I had. you should probably use the built-in one, now that it has it

profile.txt

export PS1="\W\$(git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/ # \1/' -e \"s/(no branch)/\$(git rev-parse --short HEAD 2> /dev/null)…/\") \$ "

This requires a call to git-branch and to git-rev-parse for every shell
prompt to be displayed. This did not result in a noticeable delay for
me, your milage may vary. If we're in a git repository it adds a hash
sign and the name of the current branch to the prompt. If we're not at
the head of the branch, it displays the short form of the HEAD's SHA.

	~ $ cd src
	src $ cd blog
	blog # master $ g co HEAD~
	blog # 5eee687… $ g co HEAD~
	blog # 8af5aec… $ g co master
	blog # master $