note 26063 added to ref.network

Previous example of IP range to CIDR list does not cope with ranges as well as the perl Net::Netmask range2cidrlist() function. In PHP this looks like <? function imask($this) { // use base_convert not dechex because dechex is broken and returns 0x80000000 instead of 0xffffffff return base_convert((pow(2,32) - pow(2, (32-$this)))), 10, 16); } function imaxblock($ibase, $tbit) { while ($tbit > 0) { $im = hexdec(imask($tbit-1)); $imand = $ibase & $im; if ($imand != $ibase) { break; } $tbit--; } return $tbit; } function range2cidrlist($istart, $iend) { // this function returns an array of cidr lists that map the range given $s = explode(".", $istart); // PHP ip2long does not handle leading zeros on IP addresses! 172.016 comes back as 172.14, seems to be treated as octal! $start = ""; $dot = ""; while (list($key,$val) = each($s)) { $start = sprintf("%s%s%d",$start,$dot,$val); $dot = "."; } $end = ""; $dot = ""; $e = explode(".",$iend); while (list($key,$val) = each($e)) { $end = sprintf("%s%s%d",$end,$dot,$val); $dot = "."; } $start = ip2long($start); $end = ip2long($end); $result = array(); while ($end > $start) { $maxsize = imaxblock($start,32); $x = log($end - $start + 1)/log(2); $maxdiff = floor(32 - floor($x)); $ip = long2ip($start); if ($maxsize < $maxdiff) { $maxsize = $maxdiff; } array_push($result,"$ip/$maxsize"); $start += pow(2, (32-$maxsize)); } return $result; } ?> -- http://www.php.net/manual/en/ref.network.php http://master.php.net/manage/user-notes.php?action=edit+26063 http://master.php.net/manage/user-notes.php?action=delete+26063 http://master.php.net/manage/user-notes.php?action=reject+26063