(Un)Stow

Offers a nice & powerful OOP and/or FP interface for PHP's pack and unpack functions.

Install

Install with Composer

$ composer require jordanbrauer/un-stow

Examples

Below are a few basic examples of how to use this library.

Hello World

Simple "Hello World!" example for packing (stow) and unpacking (unstow) hexadecimal data.

stow('48656C6C6F20576F726C6421')->hexNibbleHigh('*')->close();
# = (string) Hello World!

unstow('Hello World!')->hexNibbleHigh('*', 'hello_world')->open();
# = (array) [
#     'hello_world' => 48656C6C6F20576F726C6421,
# ],

GIF Header

Even though we have other methods of checking for GIF image data now, this serves as a good example of how unstow works for unpacking binary data to read headers.

$stream = fopen('./tests/Portal.gif', 'rb');
$bytes = fread($stream, 20);

fclose($stream);

$gifHeader = unstow($bytes)
    ->spacePaddedString(6, 'version')
    ->unsignedChar(2, 'width')
    ->unsignedChar(2, 'height')
    ->unsignedChar(1, 'flag')
    ->nullFill(11)
    ->unsignedChar(1, 'aspect')
    ->open();

Reusing Packers

With this library you are able to create "template" packers and unpackers which have a predefined pattern and can accept arbitrary data to pack/unpack.

Object-Oriented Method

To re-use a packer in an OOP way, simply omit the bytes from your constructor and chain your format method calls to create your pattern. Next you can pass arbitrary data to the load method on and call close/open to process the data according to the format.

E.g.,

$packer = stow()
    ->unsignedShort('', Stow::BIG_ENDIAN_16_BIT)
    ->unsignedShort('', Stow::LITTLE_ENDIAN_16_BIT)
    ->signedChar('*');

echo $packer->load(0x1234, 0x5678, 65, 66)->close();

Functional Method

The functional method is quite similar to the object-oriented way, except two small differences.

1. After chaining all your format method calls, finish it off by calling the standby method.
   • This method will return a closure that accepts a set of variadic arguments of arbitrary data.
2. No need to call the open/close methods: the closure simply returns the packed/unpacked data!

E.g.,

$packer = stow()
    ->unsignedShort('', Stow::BIG_ENDIAN_16_BIT)
    ->unsignedShort('', Stow::LITTLE_ENDIAN_16_BIT)
    ->signedChar('*')
    ->standby();

echo $packer(0x1234, 0x5678, 65, 66);