note 100548 added to function.unpack

The documentation is clear that an integer read using an unsigned format character will still be stored as a signed integer. The often-cited work-around is to use sprintf('%u', $bigint) to properly display integers with the MSB set. In the case where the numeric value is more important than how it's displayed, you can still work with other large integers using intval() to "upgrade" your existing unsigned integers. I had a problem comparing 32-bit integers read from files with hard-coded constants (file signatures tend to need this). Here's what I did to avoid converting everything into strings: <?php $bigint = 0x89504E47; $packed = pack('N', $bigint); list($unpacked) = array_values(unpack('N', $packed)); //The $bigint remains an unsigned integer. //Even though their bit-wise values are identical, comparison fails. echo 'bigint ', ($bigint == $unpacked ? '==' : '!='), " unpacked\n"; //intval() triggers a re-interpretation of $bigint. //$bigint is internally compared as a signed integer. //Since the bit-wise value of $bigint never changes, comparison succeeds. echo 'intval(bigint) ', (intval($bigint) == $unpacked ? '==' : '!='), " unpacked\n"; ?> It works, but it's a little backwards. If anyone has any ideas on how to "downgrade" a signed integer into an unsigned integer without using strings, that would be a valuable note to add to the documentation. ---- Server IP: 208.69.120.55 Probable Submitter: 76.212.32.90 ---- Manual Page -- http://www.php.net/manual/en/function.unpack.php Edit -- https://master.php.net/note/edit/100548 Del: integrated -- https://master.php.net/note/delete/100548/integrated Del: useless -- https://master.php.net/note/delete/100548/useless Del: bad code -- https://master.php.net/note/delete/100548/bad+code Del: spam -- https://master.php.net/note/delete/100548/spam Del: non-english -- https://master.php.net/note/delete/100548/non-english Del: in docs -- https://master.php.net/note/delete/100548/in+docs Del: other reasons-- https://master.php.net/note/delete/100548 Reject -- https://master.php.net/note/reject/100548 Search -- https://master.php.net/manage/user-notes.php