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unpack

(PHP 4, PHP 5)

unpack — Unpack data from binary string

Description

array unpack ( string $format , string $data )

Unpacks from a binary string into an array according to the given format .

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.

See Also