Unpack data from binary string

说明

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 /.

参数

format: See pack() for an explanation of the format codes.
data: The packed data.

返回值

Returns an associative array containing unpacked elements of binary string.

范例

Example#1 unpack() example


<?php
$array = unpack("c2chars/nint", $binarydata);
?>

The resulting array will contain the entries "chars1", "chars2" and "int".

注释

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.

参见

pack()