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phpc++long-integerunsignedpack

PHP string to "unsigned long" (from C++)


I have this code in C++, which returns outputs the following number

int main(int argn, char** argv)
{
    cout << (*((unsigned long*)"P3TF")) << endl;
    cin.get();
    return 0;
}

How can I achieve the above in PHP (i.e. the string "P3TF" in unsigned long int). I tried using the pack method:

<?php
$lol = pack('N', 'P3TF');
var_dump( $lol, // returns jumbled up characters
          ord($lol[0]), // returns int 0
          ord($lol[1]), // returns int 0
          ord($lol[2]), // returns int 0
          ord($lol[3]), // returns int 0
          ord($lol[0]).ord($lol[1]).ord($lol[2]).ord($lol[3]) // returns 4 zeros as a string.
);
?>

I need it in bigendian byte order so I haven't used pack('V') or pack('L').

Anyone know how to achieve this?

Thanks!


Solution

  • If it's literally "P3TF" in the real code, why not convert it once, and define a constant in the PHP code?

    Failing that, you need unpack, not pack. e.g. running

    <?php
    $in = 'P3TF';
    $arr = unpack('N', $in);
    printf("%08x\n", $arr[1]);
    ?>
    

    Gives 50335446, which is the ASCII codes for 'P' '3' 'T' 'F' in hex (concatenated)