Augmenting your shell prompt with Git information

I use git, and from time to time I use the ‘stash’ feature. This is a boon when performing certain tasks, but can also get you into trouble if you don’t carefully manage what you’ve stashed. To this end, I modified my bash shell prompt to help me remember.

Normally my shell prompt gives me fairly standard information. Current working directory, time, hostname and current user.

[nick@20:47:31] dusk : ~/Work
$ 

When I’m inside a git repository, I see something like this.

[nick@20:47:31] dusk : ~/Work/git/MacRuby (master) [2]
$ 

The bracketed ‘master’ shows me what branch I have checked out, and the red ‘2’ shows me that I have two stashed change-sets. This is accomplished by the following bashrc/profile code:

function parse_git_branch {
  ref=$(git symbolic-ref HEAD 2> /dev/null) || return
  echo "("${ref#refs/heads/}")"
}

function parse_git_stash_size {
  lines=$(git stash list -n 100 2> /dev/null) || return
  if [ "${#lines}" -gt 0 ]
  then
    count=$(echo "$lines" | wc -l | sed 's/^[ \t]*//') # strip tabs
    echo "["${count#}"]"
  fi
}

export PS1="[$red\u$NC@$green\t$NC] \h : $cyan\w $yellow\$(parse_git_branch) $RED\$(parse_git_stash_size)\n$NC\$ "

This has been invaluable in helping me keep track of what I’m working on, and helps me make fewer mistakes when managing git repositories.