PHP中的Oracle11g大整数到十六进制字符串转换

Question

I have a column in table declared as macaddr NUMBER(15) (macaddress integer representation range - up to 15 digits)

The PHP fetch this values as a strings, obviously on 32bit system the dechex will not handle that big ints.

How I can easily convert that strings into hex macaddr representation (human redable)? And same question in opposite direction?

Answer 1

Do you really need to store these informations in a numeric form? Modern computers have plenty of space available.

Anyway you can use PHP to convert numbers larger than that.
My humble solution is to avoid relying on types provided by PHP and use the BCMath Arbitrary Precision Mathematics.
According to the manual the library comes bundled with PHP since release 4.0.4. If you run PHP in Windows it works straight. Otherwise you have to configure with --enable-bcmath .
Thanks to user contributed notes on the PHP.net website I found these two handy functions:

<?php

        /* hexadecimal to/from decimal functions from user contributed notes at http://it.php.net/manual/en/ref.bc.php */

        function bchexdec($hex) {
            if(strlen($hex) == 1) {
                return hexdec($hex);
            } else {
                $remain = substr($hex, 0, -1);
                $last = substr($hex, -1);
                return bcadd(bcmul(16, bchexdec($remain)), hexdec($last));
            }
        }

        function bcdechex($dec) {
            $last = bcmod($dec, 16);
            $remain = bcdiv(bcsub($dec, $last), 16);

            if($remain == 0) {
                return dechex($last);
            } else {
                return bcdechex($remain).dechex($last);
            }
        }

    echo bcdechex (130646634308);

    echo '<br />';

    echo bchexdec ('001e6b256f44');


    ?>