git-ps1-status

#!/usr/bin/env bash
# Make sure this runs on a modern bash with support for ;;& in case

shopt -s extglob

# Make sure we're in a git directory
if git rev-parse --git-dir > /dev/null 2>&1; then
	# Print a leading space to separate from the rest of the PS1
	printf " "
	# Check our status relative to upstream
	case "$(git rev-list --count --left-right @{upstream}...HEAD 2>/dev/null)" in
		"") # No upstream found
			;;
		"0	0") # Equal to upstream
			printf "=" ;;
		!([0])"	"*) # Less than upstream, or diverged 1/2 (and reswitch)
			printf "<" ;;&
		*"	"!([0])) # Greater than upstream, or diverged 2/2
			printf ">" ;;
	esac
	# Print the current branch or HEAD if we're not on one
	branch=$(git rev-parse --abbrev-ref HEAD 2> /dev/null)
	if [ $? -eq 0 ]; then
		echo -n $branch
	fi
	if [ $(git rev-parse --is-bare-repository) = false ]; then
		# Check if there are staged files
		if ! git diff --no-ext-diff --cached --quiet > /dev/null; then 
			printf "+"		
		fi
		# Check if there are changed files
		if ! git diff --no-ext-diff --quiet > /dev/null; then 
			printf "*"		
		fi
	fi
fi