php ip地址转换整数，整数转换地址

$ipArr    = explode('.',$_SERVER['REMOTE_ADDR']);



     $ipVal = $ipArr[0] * 0x1000000
            + $ipArr[1] * 0x10000
            + $ipArr[2] * 0x100
            + $ipArr[3]
            ;

        echo$ipVal.'
';

         $ipArr = array(0 => floor( $ipVal/ 0x1000000) );

        $ipVint   = $ipVal-($ipArr[0]*0x1000000); // for clarity$ipArr[1] = ($ipVint & 0xFF0000)  >> 16;

        $ipArr[2] = ($ipVint & 0xFF00  )  >> 8;

        $ipArr[3] =  $ipVint & 0xFF;

        $ipDotted = implode('.', $ipArr);

        echo$ipDotted;















$ipArr    = explode('.',$_SERVER['REMOTE_ADDR']);
  $ip       = $ipArr[0] * 0x1000000
            + $ipArr[1] * 0x10000
            + $ipArr[2] * 0x100
            + $ipArr[3]
            ;
?>This can be written in a bit more efficient way:
$ipArr    = explode('.',$_SERVER['REMOTE_ADDR']);
  $ip       = $ipArr[0]24
            + $ipArr[1]16
            + $ipArr[2] 8