3002 /**

  3003  * Parses a valid IP address range into a regular expression.

  3004  * @param string IP range string

  3005  * @return string

  3006  */

  3007 

  3008 function parse_ip_range_regex($range)

  3009 {

  3010   // Regular expression to test the range string for validity

  3011   $regex = '/^(([0-9]+(-[0-9]+)?)(\|([0-9]+(-[0-9]+)?))*)\.'

  3012            . '(([0-9]+(-[0-9]+)?)(\|([0-9]+(-[0-9]+)?))*)\.'

  3013            . '(([0-9]+(-[0-9]+)?)(\|([0-9]+(-[0-9]+)?))*)\.'

  3014            . '(([0-9]+(-[0-9]+)?)(\|([0-9]+(-[0-9]+)?))*)$/';

  3015   if ( !preg_match($regex, $range) )

  3016   {

  3017     return false;

  3018   }

  3019   $octets = array(0 => array(), 1 => array(), 2 => array(), 3 => array());

  3020   list($octets[0], $octets[1], $octets[2], $octets[3]) = explode('.', $range);

  3021   $return = '^';

  3022   foreach ( $octets as $octet )

  3023   {

  3024     // alternatives array

  3025     $alts = array();

  3026     if ( strpos($octet, '|') )

  3027     {

  3028       $particles = explode('|', $octet);

  3029     }

  3030     else

  3031     {

  3032       $particles = array($octet);

  3033     }

  3034     foreach ( $particles as $atom )

  3035     {

  3036       // each $atom will be either

  3037       if ( strval(intval($atom)) == $atom )

  3038       {

  3039         $alts[] = $atom;

  3040         continue;

  3041       }

  3042       else

  3043       {

  3044         // it's a range - parse it out

  3045         $alt2 = int_range($atom);

  3046         if ( !$alt2 )

  3047           return false;

  3048         foreach ( $alt2 as $neutrino )

  3049           $alts[] = $neutrino;

  3050       }

  3051     }

  3052     $alts = array_unique($alts);

  3053     $alts = '|' . implode('|', $alts) . '|';

  3054     // we can further optimize/compress this by weaseling our way into using some character ranges

  3055     for ( $i = 1; $i <= 25; $i++ )

  3056     {

  3057       $alts = str_replace("|{$i}0|{$i}1|{$i}2|{$i}3|{$i}4|{$i}5|{$i}6|{$i}7|{$i}8|{$i}9|", "|{$i}[0-9]|", $alts);

  3058     }

  3059     $alts = str_replace("|1|2|3|4|5|6|7|8|9|", "|[1-9]|", $alts);

  3060     $alts = '(' . substr($alts, 1, -1) . ')';

  3061     $return .= $alts . '\.';

  3062   }

  3063   $return = substr($return, 0, -2);

  3064   $return .= '$';

  3065   return $return;

  3066 }

  3067