2994 /**

  2995  * Parses a valid IP address range into a regular expression.

  2996  * @param string IP range string

  2997  * @return string

  2998  */

  2999 

  3000 function parse_ip_range_regex($range)

  3001 {

  3002   // Regular expression to test the range string for validity

  3003   $regex = '/^(([0-9]+(-[0-9]+)?)(\|([0-9]+(-[0-9]+)?))*)\.'

  3004            . '(([0-9]+(-[0-9]+)?)(\|([0-9]+(-[0-9]+)?))*)\.'

  3005            . '(([0-9]+(-[0-9]+)?)(\|([0-9]+(-[0-9]+)?))*)\.'

  3006            . '(([0-9]+(-[0-9]+)?)(\|([0-9]+(-[0-9]+)?))*)$/';

  3007   if ( !preg_match($regex, $range) )

  3008   {

  3009     return false;

  3010   }

  3011   $octets = array(0 => array(), 1 => array(), 2 => array(), 3 => array());

  3012   list($octets[0], $octets[1], $octets[2], $octets[3]) = explode('.', $range);

  3013   $return = '^';

  3014   foreach ( $octets as $octet )

  3015   {

  3016     // alternatives array

  3017     $alts = array();

  3018     if ( strpos($octet, '|') )

  3019     {

  3020       $particles = explode('|', $octet);

  3021     }

  3022     else

  3023     {

  3024       $particles = array($octet);

  3025     }

  3026     foreach ( $particles as $atom )

  3027     {

  3028       // each $atom will be either

  3029       if ( strval(intval($atom)) == $atom )

  3030       {

  3031         $alts[] = $atom;

  3032         continue;

  3033       }

  3034       else

  3035       {

  3036         // it's a range - parse it out

  3037         $alt2 = int_range($atom);

  3038         if ( !$alt2 )

  3039           return false;

  3040         foreach ( $alt2 as $neutrino )

  3041           $alts[] = $neutrino;

  3042       }

  3043     }

  3044     $alts = array_unique($alts);

  3045     $alts = '|' . implode('|', $alts) . '|';

  3046     // we can further optimize/compress this by weaseling our way into using some character ranges

  3047     for ( $i = 1; $i <= 25; $i++ )

  3048     {

  3049       $alts = str_replace("|{$i}0|{$i}1|{$i}2|{$i}3|{$i}4|{$i}5|{$i}6|{$i}7|{$i}8|{$i}9|", "|{$i}[0-9]|", $alts);

  3050     }

  3051     $alts = str_replace("|1|2|3|4|5|6|7|8|9|", "|[1-9]|", $alts);

  3052     $alts = '(' . substr($alts, 1, -1) . ')';

  3053     $return .= $alts . '\.';

  3054   }

  3055   $return = substr($return, 0, -2);

  3056   $return .= '$';

  3057   return $return;

  3058 }

  3059