README.md

# ramsey/uuid

*IMPORTANT: This is the 3.x series. Please upgrade to the 4.x series.*

*NOTICE: Formerly known as `rhumsaa/uuid`, The package and namespace names have
changed to `ramsey/uuid` and `Ramsey\Uuid`, respectively.*

[![Source Code][badge-source]][source]
[![Series][badge-series]][series]
[![Upgrade][badge-upgrade]][upgrade]
[![PHP Version][badge-php]][php]
[![Software License][badge-license]][license]
[![Build Status][badge-build]][build]
[![Coverage Status][badge-coverage]][coverage]

ramsey/uuid is a PHP 5.4+ library for generating and working with
[RFC 4122][rfc4122] version 1, 3, 4, and 5 universally unique identifiers
(UUID).

This project adheres to a [Contributor Code of Conduct][conduct]. By
participating in this project and its community, you are expected to uphold this
code.

From [Wikipedia](http://en.wikipedia.org/wiki/Universally_unique_identifier):

> 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][javauuid] and
[Python][pyuuid] UUID libraries.


## Installation

The preferred method of installation is via [Composer][]. Run the following
command to install the package and add it as a requirement to your project's
`composer.json`:

```bash
composer require ramsey/uuid
```


## Upgrading from 2.x to 3.x

While we have made significant internal changes to the library, we have made
every effort to ensure a seamless upgrade path from the 2.x series of this
library to 3.x.

One major breaking change is the transition from the `Rhumsaa` root namespace to
`Ramsey`. In most cases, all you will need is to change the namespace to
`Ramsey` in your code, and everything will "just work."

Here are full details on the breaking changes to the public API of this library:

1. All namespace references of `Rhumsaa` have changed to `Ramsey`. Simply change
   the namespace to `Ramsey` in your code and everything should work.
2. The console application has moved to
   [ramsey/uuid-console](https://packagist.org/packages/ramsey/uuid-console).
   If using the console functionality, use Composer to require
   `ramsey/uuid-console`.
3. The Doctrine field type mapping has moved to
   [ramsey/uuid-doctrine](https://packagist.org/packages/ramsey/uuid-doctrine).
   If using the Doctrine functionality, use Composer to require
   `ramsey/uuid-doctrine`.


## What to do if you see a "rhumsaa/uuid is abandoned" message

When installing your project's dependencies using Composer, you might see the
following message:

```
Package rhumsaa/uuid is abandoned, you should avoid using it. Use
ramsey/uuid instead.
```

Don't panic. Simply execute the following commands with Composer:

``` bash
composer remove rhumsaa/uuid
composer require ramsey/uuid=^2.9
```

After doing so, you will have the latest ramsey/uuid package in the 2.x series,
and there will be no need to modify any code; the namespace in the 2.x series is
still `Rhumsaa`.


## Requirements

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 an
`UnsatisfiedDependencyException` is thrown, allowing one to catch a bad call in
an environment where the call is not supported and gracefully degrade.


## Examples

See the [cookbook on the wiki][wiki-cookbook] for more examples and approaches
to specific use-cases.

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

use Ramsey\Uuid\Uuid;
use Ramsey\Uuid\Exception\UnsatisfiedDependencyException;

try {

    // Generate a version 1 (time-based) UUID object
    $uuid1 = Uuid::uuid1();
    echo $uuid1->toString() . "\n"; // i.e. 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"; // i.e. 11a38b9a-b3da-360f-9353-a5a725514269

    // Generate a version 4 (random) UUID object
    $uuid4 = Uuid::uuid4();
    echo $uuid4->toString() . "\n"; // i.e. 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"; // i.e. 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";

}
```


## Contributing

Contributions are welcome! Please read [CONTRIBUTING.md][] for details.


## Copyright and License

The ramsey/uuid library is copyright © [Ben Ramsey](https://benramsey.com/) and
licensed for use under the MIT License (MIT). Please see [LICENSE][] for more
information.


[rfc4122]: http://tools.ietf.org/html/rfc4122
[conduct]: https://github.com/ramsey/uuid/blob/master/.github/CODE_OF_CONDUCT.md
[javauuid]: http://docs.oracle.com/javase/6/docs/api/java/util/UUID.html
[pyuuid]: http://docs.python.org/3/library/uuid.html
[composer]: http://getcomposer.org/
[moontoast\math]: https://packagist.org/packages/moontoast/math
[wiki-cookbook]: https://github.com/ramsey/uuid/wiki/Ramsey%5CUuid-Cookbook
[contributing.md]: https://github.com/ramsey/uuid/blob/master/.github/CONTRIBUTING.md

[badge-source]: https://img.shields.io/badge/source-ramsey/uuid-blue.svg?style=flat-square
[badge-series]: https://img.shields.io/badge/series-3.x-darkcyan.svg?style=flat-square
[badge-upgrade]: https://img.shields.io/packagist/v/ramsey/uuid.svg?style=flat-square&label=upgrade&colorB=darkred
[badge-license]: https://img.shields.io/packagist/l/ramsey/uuid.svg?style=flat-square&colorB=darkcyan
[badge-php]: https://img.shields.io/packagist/php-v/ramsey/uuid/3.x-dev.svg?style=flat-square&colorB=%238892BF
[badge-build]: https://img.shields.io/github/workflow/status/ramsey/uuid/build/3.x.svg?logo=github&style=flat-square
[badge-coverage]: https://img.shields.io/codecov/c/gh/ramsey/uuid/3.x.svg?style=flat-square&logo=codecov

[source]: https://github.com/ramsey/uuid/tree/3.x
[series]: https://packagist.org/packages/ramsey/uuid
[upgrade]: https://packagist.org/packages/ramsey/uuid
[license]: https://github.com/ramsey/uuid/blob/master/LICENSE
[php]: https://php.net
[build]: https://github.com/ramsey/uuid/actions/workflows/continuous-integration.yml?query=branch%3A3.x
[coverage]: https://app.codecov.io/gh/ramsey/uuid/branch/3.x