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Ben Ramsey
31 lines
1.1 KiB
ReStructuredText
31 lines
1.1 KiB
ReStructuredText
.. _introduction:
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============
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Introduction
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============
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ramsey/uuid is a PHP library for generating and working with `RFC 9562`_ (formerly `RFC 4122`_) version 1, 2, 3, 4, 5,
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6, 7, and 8 universally unique identifiers (UUID). ramsey/uuid also supports optional and non-standard features, such as
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GUIDs and other approaches for encoding/decoding UUIDs.
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What Is a UUID?
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###############
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A universally unique identifier, or UUID, is a 128-bit unsigned integer, usually represented as a hexadecimal string
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split into five groups with dashes. The most widely-known and used types of UUIDs are defined by `RFC 9562`_ (formerly
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`RFC 4122`_).
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A UUID, when encoded in hexadecimal string format, looks like:
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.. code-block:: text
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ebb5c735-0308-4e3c-9aea-8a270aebfe15
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The probability of duplicating a UUID is close to zero, so they are a great choice for generating unique identifiers in
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distributed systems.
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UUIDs can also be stored in binary format, as a string of 16 bytes.
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.. _RFC 4122: https://www.rfc-editor.org/rfc/rfc4122
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.. _RFC 9562: https://www.rfc-editor.org/rfc/rfc9562
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