# File lib/specinfra/command/base/file.rb, line 35
    def check_is_grouped(file, group)
      regexp = "^#{group}$"
      if group.is_a?(Numeric) || (group =~ /\A\d+\z/ ? true : false)
        "stat -c %g #{escape(file)} | grep -- #{escape(regexp)}"
      else
        "stat -c %G #{escape(file)} | grep -- #{escape(regexp)}"
      end
    end