unpack
(PHP 4, PHP 5)
unpack — Unpack data from binary string
Description
array unpack
( string $format
, string $data
)
unpack() works slightly different from Perl as
the unpacked data is stored in an associative array. To
accomplish this you have to name the different format codes and
separate them by a slash /.
Parameters
-
format
-
See pack() for an explanation of the format codes.
-
data
-
The packed data.
Return Values
Returns an associative array containing unpacked elements of binary
string.
Examples
Example #1 unpack() example
<?php
$array = unpack("c2chars/nint", $binarydata);
?>
The resulting array will contain the entries "chars1",
"chars2" and "int".
Notes
Caution
Note that PHP internally stores integral values as signed. If you
unpack a large unsigned long and it is of the same size as PHP
internally stored values the result will be a negative number
even though unsigned unpacking was specified.