$html =~ s/
      (<\s*
         (?:a|img|area)
         [^>]+?(?:href|src)
         \s*=\s*
         ["']?
      )
      (
         [^'"\/>(http|telnet|gopher|file|wais|ftp)]
         [^'" >]+?
      )
      ([ '"]?>)
      /
      $1.sprintf("%s%s", $path, $2).$3
      /sigex;