note 99251 added to function.ip2long

For purely practise (and a better understanding of bytes), you could write an efficient alternative using PHP's bitshift operators to handle the division/multiplication/powers: <?php function _ip2long($arg) { $numbers = explode (".", $arg); return ( $numbers[0] << 24) + ( $numbers[1] << 16) + ( $numbers[2] << 8 ) + ( $numbers[3] ); } function _long2ip($arg) { return ($arg >> 24 & 255) . "." . ($arg >> 16 & 255) . "." . ($arg >> 8 & 255) . "." . ($arg & 255); } //2130706433 print $ip = _ip2long($_SERVER['REMOTE_ADDR']) . "<br/>"; //127.0.0.1 print _long2ip($ip); ?> ---- Server IP: 66.207.199.35 Probable Submitter: 174.1.235.8 ---- Manual Page -- http://www.php.net/manual/en/function.ip2long.php Edit -- https://master.php.net/note/edit/99251 Del: integrated -- https://master.php.net/note/delete/99251/integrated Del: useless -- https://master.php.net/note/delete/99251/useless Del: bad code -- https://master.php.net/note/delete/99251/bad+code Del: spam -- https://master.php.net/note/delete/99251/spam Del: non-english -- https://master.php.net/note/delete/99251/non-english Del: in docs -- https://master.php.net/note/delete/99251/in+docs Del: other reasons-- https://master.php.net/note/delete/99251 Reject -- https://master.php.net/note/reject/99251 Search -- https://master.php.net/manage/user-notes.php