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Ben Ramsey
32 lines
981 B
ReStructuredText
32 lines
981 B
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 4122`_ version
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1, 2, 3, 4, 5, 6, and 7 universally unique identifiers (UUID). ramsey/uuid also
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supports optional and non-standard features, such as GUIDs and other approaches
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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
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represented as a hexadecimal string split into five groups with dashes. The most
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widely-known and used types of UUIDs are defined by `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
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choice for generating unique identifiers in 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://tools.ietf.org/html/rfc4122
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