code: function gitStatus(file, callback) {
          exec('git status --porcelain ' + file, {}, function (error, stdout, stderr) {
              if (error || stderr) {
                  grunt.fatal("Error with git status: " + stderr);
              }
              callback(stdout ? false : true);
          });
      }
docs: Helper function for checking if the file is clean with git status. callback will be called with either true/false (true means it's clean)