BASH prompt with git branch name and status. Fixed to handle directory names with spaces and checks to see if nested directories are under source control.

bash_prompt

#!/bin/bash

# BASH prompt builder
#
# This is a script I use to generate BASH prompts that look like this:
# (master)*
# [sbilstei@sbilstei-mn1:~/localcode/git-sandbox]:$
#
# Basically user, the machine's hostname, current working directory tilde condensed and an optional branch name
# when navigating a git repo. The asterisk is visible if there are uncommitted changes. 
#  
# To use this script add the following lines to your .bash_profile:
#
#  function prompt_command {
#    export PS1=$(<scriptlocation>)
#  }
#  export PROMPT_COMMAND=prompt_command 
#  
# where <scriptlocation> is the location of this script. You will also need to set execute permissions on the script by typing:
# chmod 744 <script>
# By tying the execution of this script to PROMPT_COMMAND
# we can guarantee that the branch status gets updated on every new prompt. Check out this SO post on the 
# topic: http://stackoverflow.com/a/11107564/608801
#

function git_changed {
  if [ ! -z "$(git diff-index --name-only HEAD --)" ]; then  
    echo "*"   
  fi  
}

# Substitute a leading path that's in $HOME for "~"
function pwd_short {
  local dir="$PWD"
  if [[ "$HOME" == ${dir:0:${#HOME}} ]] ; then
    dir="~${dir:${#HOME}}"
  fi
  echo "${dir}"
}

function git_branch_and_status {
  local maxlen=30
  local truncatelen=maxlen-3
  local is_repo=$(git rev-parse --is-inside-work-tree 2> /dev/null)
  if [ "$is_repo" = "true" ]; then
    ref=$(git symbolic-ref HEAD 2> /dev/null)
    local branch=${ref#refs/heads/}
    namelength=${#branch}
    if [ $namelength -gt $maxlen ]; then
      branch="${branch:0:${truncatelen}}..."
    else 
      branch="${branch}"
    fi 
    echo "(${branch})$(git_changed)\n"
  else 
    echo ""
  fi    
}
echo -e "$(git_branch_and_status)[$USER@$HOSTNAME:$(pwd_short)]$ "

You might want to wrap "$(git diff-index --name-only HEAD --)" in double quotes, otherwise this script does not handle working directories containing spaces.

I got this to work by saving this as an (extensionless) file in my ~/bin directory ("bash_prompt"), then by placing the below code in my /.bash_profile, replacing "< scriptlocation >" below with "/bin/bash_prompt

function prompt_command {
   export PS1=$(<scriptlocation>)
 }
 export PROMPT_COMMAND=prompt_command 

My prompt would be achieved by increasing maxlen (my branch and pwd are on their own line so I don't bother truncating them) and changing the last line to:

echo -e "\n(\w)-[$(git_branch_and_status)]\n\u@\h-[\D{%H:%M}]$ "

The effect is:

                                          # intentional newline        
(~/path/to/repo)-[JIRA-42-branch-name]    # pwd and branch
user@host-[12:40]$                        # prompt