UUID generator and utilities for Elixir
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README.md

Elixir UUID

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UUID generator and utilities for Elixir. See RFC 4122.

Note: Renamed from uuid to elixir_uuid as a solution to package name conflicts. Use elixir_uuid going forward.

Installation

The latest version is 1.2.0 and requires Elixir ~> 1.0. New releases may change this minimum compatible version depending on breaking language changes. The changelog lists every available release and its corresponding language version requirement.

Releases are published through hex.pm. Add as a dependency in your mix.exs file:

defp deps do
  [ { :elixir_uuid, "~> 1.2" } ]
end

UUID v1

Generated using a combination of time since the west adopted the gregorian calendar and the node id MAC address.

iex> UUID.uuid1()
"5976423a-ee35-11e3-8569-14109ff1a304"

UUID v3

Generated using the MD5 hash of a name and either a namespace atom or an existing UUID. Valid namespaces are: :dns, :url, :oid, :x500, :nil.

iex> UUID.uuid3(:dns, "my.domain.com")
"03bf0706-b7e9-33b8-aee5-c6142a816478"

iex> UUID.uuid3("5976423a-ee35-11e3-8569-14109ff1a304", "my.domain.com")
"0609d667-944c-3c2d-9d09-18af5c58c8fb"

UUID v4

Generated based on pseudo-random bytes.

iex> UUID.uuid4()
"fcfe5f21-8a08-4c9a-9f97-29d2fd6a27b9"

UUID v5

Generated using the SHA1 hash of a name and either a namespace atom or an existing UUID. Valid namespaces are: :dns, :url, :oid, :x500, :nil.

iex> UUID.uuid5(:dns, "my.domain.com")
"016c25fd-70e0-56fe-9d1a-56e80fa20b82"

iex> UUID.uuid5("fcfe5f21-8a08-4c9a-9f97-29d2fd6a27b9", "my.domain.com")
"b8e85535-761a-586f-9c04-0fb0df2cbe84"

Formatting

All UUID generator functions have an optional format parameter as the last argument.

Possible values: :default, :hex, :urn. Default value is :default and can be omitted.

:default is a standard UUID representation:

iex> UUID.uuid1()
"3c69679f-774b-4fb1-80c1-7b29c6e7d0a0"

iex> UUID.uuid4(:default)
"3c69679f-774b-4fb1-80c1-7b29c6e7d0a0"

iex> UUID.uuid3(:dns, "my.domain.com")
"03bf0706-b7e9-33b8-aee5-c6142a816478"

iex> UUID.uuid5(:dns, "my.domain.com", :default)
"016c25fd-70e0-56fe-9d1a-56e80fa20b82"

:hex is a valid hex string, corresponding to the standard UUID without the - (dash) characters:

iex> UUID.uuid4(:hex)
"19be859d0c1f4a7f95ddced995037350"

iex> UUID.uuid4(:weak, :hex)
"ebeff765ddc843e486c287fb668d5d37"

:urn is a standard UUID representation prefixed with the UUID URN:

iex> UUID.uuid1(:urn)
"urn:uuid:b7483bde-ee35-11e3-8daa-14109ff1a304"

Utility functions

Use UUID.info/1 and UUID.info!/1 to get a keyword list containing information about the given UUID. UUID.info/1 returns a tuple of {:ok, info} for valid cases or {:error, reason} if the argument is not a UUID string. UUID.info!/1 directly returns the info keyword list when successful or raises an ArgumentError for error cases.

iex> UUID.info!("870df8e8-3107-4487-8316-81e089b8c2cf")
[uuid: "870df8e8-3107-4487-8316-81e089b8c2cf",
 binary: <<135, 13, 248, 232, 49, 7, 68, 135, 131, 22, 129, 224, 137, 184, 194, 207>>,
 type: :default,
 version: 4,
 variant: :rfc4122]

iex> UUID.info!("8ea1513df8a14dea9bea6b8f4b5b6e73")
[uuid: "8ea1513df8a14dea9bea6b8f4b5b6e73",
 binary: <<142, 161, 81, 61, 248, 161, 77, 234, 155, 234, 107, 143, 75, 91, 110, 115>>,
 type: :hex,
 version: 4,
 variant: :rfc4122]

iex> UUID.info!("urn:uuid:ef1b1a28-ee34-11e3-8813-14109ff1a304")
[uuid: "urn:uuid:ef1b1a28-ee34-11e3-8813-14109ff1a304",
 binary: <<239, 27, 26, 40, 238, 52, 17, 227, 136, 19, 20, 16, 159, 241, 163, 4>>,
 type: :urn,
 version: 1,
 variant: :rfc4122]

Use UUID.string_to_binary!/1 to convert a valid UUID string to its raw binary equivalent. An ArgumentError is raised if the argument is not a valid UUID string.

iex> UUID.string_to_binary!("870df8e8-3107-4487-8316-81e089b8c2cf")
<<135, 13, 248, 232, 49, 7, 68, 135, 131,
            22, 129, 224, 137, 184, 194, 207>>

iex> UUID.string_to_binary!("8ea1513df8a14dea9bea6b8f4b5b6e73")
<<142, 161, 81, 61, 248, 161, 77, 234, 155,
            234, 107, 143, 75, 91, 110, 115>>


iex> UUID.string_to_binary!("urn:uuid:ef1b1a28-ee34-11e3-8813-14109ff1a304")
<<239, 27, 26, 40, 238, 52, 17, 227, 136,
            19, 20, 16, 159, 241, 163, 4>>

Use UUID.binary_to_string!/2 to convert valid UUID binary data to a String representation, with an optional format similar to the generator functions above. An ArgumentError is raised if the argument is not valid UUID binary data.

iex> UUID.binary_to_string!(<<135, 13, 248, 232, 49, 7, 68, 135, 131,
            22, 129, 224, 137, 184, 194, 207>>)
"870df8e8-3107-4487-8316-81e089b8c2cf"

iex> UUID.binary_to_string!(<<142, 161, 81, 61, 248, 161, 77, 234, 155,
            234, 107, 143, 75, 91, 110, 115>>, :hex)
"8ea1513df8a14dea9bea6b8f4b5b6e73"

iex> UUID.binary_to_string!(<<239, 27, 26, 40, 238, 52, 17, 227, 136,
            19, 20, 16, 159, 241, 163, 4>>, :urn)
"urn:uuid:ef1b1a28-ee34-11e3-8813-14109ff1a304"

Attribution

Some code ported from avtobiff/erlang-uuid.

Some helper functions from rjsamson/hexate.

License

Copyright 2014-2016 Andrei Mihu

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.