WARNING: This package is no longer maintained. Use ramsey/uuid instead.

Rhumsaa\Uuid is a PHP 5.3+ library for generating and working with RFC 4122 version 1, 3, 4, and 5 universally unique identifiers (UUID).

From Wikipedia:

The intent of UUIDs is to enable distributed systems to uniquely identify information without significant central coordination. In this context the word unique should be taken to mean "practically unique" rather than "guaranteed unique". Since the identifiers have a finite size, it is possible for two differing items to share the same identifier. The identifier size and generation process need to be selected so as to make this sufficiently improbable in practice. Anyone can create a UUID and use it to identify something with reasonable confidence that the same identifier will never be unintentionally created by anyone to identify something else. Information labeled with UUIDs can therefore be later combined into a single database without needing to resolve identifier (ID) conflicts.

Much inspiration for this library came from the Java and Python UUID libraries.

The latest class API documentation is available online. This project uses ApiGen to generate this documentation. To generate the documentation on your own, run apigen from the root of the project. This will generate documentation in the build/apidocs/ folder.

Some methods in this library have requirements due to integer size restrictions on 32-bit and 64-bit builds of PHP. A 64-bit build of PHP and the Moontoast\Math library are recommended. However, this library is designed to work on 32-bit builds of PHP without Moontoast\Math, with some degraded functionality. Please check the API documentation for more information.

If a particular requirement is not present, then a Rhumsaa\Uuid\Exception\UnsatisfiedDependencyException is thrown, allowing one to catch a bad call in an environment where the call is not supported and gracefully degrade.

<?php
require 'vendor/autoload.php';

use Rhumsaa\Uuid\Uuid;
use Rhumsaa\Uuid\Exception\UnsatisfiedDependencyException;

try {

    // Generate a version 1 (time-based) UUID object
    $uuid1 = Uuid::uuid1();
    echo $uuid1->toString() . "\n"; // e4eaaaf2-d142-11e1-b3e4-080027620cdd

    // Generate a version 3 (name-based and hashed with MD5) UUID object
    $uuid3 = Uuid::uuid3(Uuid::NAMESPACE_DNS, 'php.net');
    echo $uuid3->toString() . "\n"; // 11a38b9a-b3da-360f-9353-a5a725514269

    // Generate a version 4 (random) UUID object
    $uuid4 = Uuid::uuid4();
    echo $uuid4->toString() . "\n"; // 25769c6c-d34d-4bfe-ba98-e0ee856f3e7a

    // Generate a version 5 (name-based and hashed with SHA1) UUID object
    $uuid5 = Uuid::uuid5(Uuid::NAMESPACE_DNS, 'php.net');
    echo $uuid5->toString() . "\n"; // c4a760a8-dbcf-5254-a0d9-6a4474bd1b62

} catch (UnsatisfiedDependencyException $e) {

    // Some dependency was not met. Either the method cannot be called on a
    // 32-bit system, or it can, but it relies on Moontoast\Math to be present.
    echo 'Caught exception: ' . $e->getMessage() . "\n";

}

The preferred method of installation is via Packagist and Composer. Run the following command to install the package and add it as a requirement to composer.json:

composer.phar require "ramsey/uuid=~2.8"