#32700 [Opn->Bgs]: unpack() returns signed values when it shouldn't
| From: | derick@php.net | Date: | Wed, 13 Apr 2005 20:54:13 +0000 |
| Subject: | #32700 [Opn->Bgs]: unpack() returns signed values when it shouldn't | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-77482@lists.php.net to get a copy of this message | ||
ID: 32700
Updated by: derick@php.net
Reported By: ieure@php.net
-Status: Open
+Status: Bogus
Bug Type: Unknown/Other Function
Operating System: Linux
PHP Version: 4.3.10
New Comment:
Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to
report
a bug at http://bugs.php.net/how-to-report.php
PHP only supports signed integers.
Previous Comments:
------------------------------------------------------------------------
[2005-04-13 22:49:33] ieure@php.net
Description:
------------
unpack() returns signed long values when the high bit is
set, even though the unpack format is set to unsigned long.
Workaround:
$foo = unpack('N', $data);
$foo = $foo << 1 >> 1;
$foo += 0x80000000;
Reproduce code:
---------------
// High bit is set.
$before = 0x80000002;
echo "Before: $before\n"; // Outputs '2147483650'
$int = pack('N', $before);
$res = unpack('N', $int);
$after = $res[1];
echo "After: $after\n"; // Outputs '-2147483646'
Expected result:
----------------
$before and $after should be the same number.
Actual result:
--------------
$after is treated as signed, and does not equal $before.
Script output:
Before: 2147483650
After: -2147483646
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=32700&edit=1