print project root directory (takes an optional relative or absolute path, defaults to pwd)

project

#!/bin/bash
if [ "${1:0:1}" == '/' ]; then
	dir="$(dirname $1)"
else
	dir="$(pwd)/$1"
fi
project_root_files=".git .hg .project"

while [ "$dir" != '/' ] && [ -z "$project_root" ]; do
	for file in $project_root_files; do
		[ -e "$dir/$file" ] && project_root="$dir"
	done
	dir=$(dirname "$dir")
done

if [ -z "$project_root" ]; then
	pwd
	exit 1
else
	echo "$project_root"
fi