“`javascript –hide
runmd.onRequire = path => path.replace(/^uuid/, ‘./’);
“`
# uuid [![Build Status](https://secure.travis-ci.org/kelektiv/node-uuid.svg?branch=master)](http://travis-ci.org/kelektiv/node-uuid) #
Simple, fast generation of [RFC4122](http://www.ietf.org/rfc/rfc4122.txt) UUIDS.
Features:
* Support for version 1, 3, 4 and 5 UUIDs
* Cross-platform
* Uses cryptographically-strong random number APIs (when available)
* Zero-dependency, small footprint (… but not [this small](https://gist.github.com/982883))
[**Deprecation warning**: The use of `require(‘uuid’)` is deprecated and will not be
supported after version 3.x of this module. Instead, use `require(‘uuid/[v1|v3|v4|v5]’)` as shown in the examples below.]
## Quickstart – CommonJS (Recommended)
“`shell
npm install uuid
“`
Then generate your uuid version of choice …
Version 1 (timestamp):
“`javascript –run v1
const uuidv1 = require(‘uuid/v1’);
uuidv1(); // RESULT
“`
Version 3 (namespace):
“`javascript –run v3
const uuidv3 = require(‘uuid/v3’);
// … using predefined DNS namespace (for domain names)
uuidv3(‘hello.example.com’, uuidv3.DNS); // RESULT
// … using predefined URL namespace (for, well, URLs)
uuidv3(‘http://example.com/hello’, uuidv3.URL); // RESULT
// … using a custom namespace
//
// Note: Custom namespaces should be a UUID string specific to your application!
// E.g. the one here was generated using this modules `uuid` CLI.
const MY_NAMESPACE = ‘1b671a64-40d5-491e-99b0-da01ff1f3341’;
uuidv3(‘Hello, World!’, MY_NAMESPACE); // RESULT
“`
Version 4 (random):
“`javascript –run v4
const uuidv4 = require(‘uuid/v4’);
uuidv4(); // RESULT
“`
Version 5 (namespace):
“`javascript –run v5
const uuidv5 = require(‘uuid/v5’);
// … using predefined DNS namespace (for domain names)
uuidv5(‘hello.example.com’, uuidv5.DNS); // RESULT
// … using predefined URL namespace (for, well, URLs)
uuidv5(‘http://example.com/hello’, uuidv5.URL); // RESULT
// … using a custom namespace
//
// Note: Custom namespaces should be a UUID string specific to your application!
// E.g. the one here was generated using this modules `uuid` CLI.
const MY_NAMESPACE = ‘1b671a64-40d5-491e-99b0-da01ff1f3341’;
uuidv5(‘Hello, World!’, MY_NAMESPACE); // RESULT
“`
## Quickstart – Browser-ready Versions
Browser-ready versions of this module are available via [wzrd.in](https://github.com/jfhbrook/wzrd.in).
For version 1 uuids:
“`html
“`
For version 3 uuids:
“`html
“`
For version 4 uuids:
“`html
“`
For version 5 uuids:
“`html
“`
## API
### Version 1
“`javascript
const uuidv1 = require(‘uuid/v1’);
// Incantations
uuidv1();
uuidv1(options);
uuidv1(options, buffer, offset);
“`
Generate and return a RFC4122 v1 (timestamp-based) UUID.
* `options` – (Object) Optional uuid state to apply. Properties may include:
* `node` – (Array) Node id as Array of 6 bytes (per 4.1.6). Default: Randomly generated ID. See note 1.
* `clockseq` – (Number between 0 – 0x3fff) RFC clock sequence. Default: An internally maintained clockseq is used.
* `msecs` – (Number) Time in milliseconds since unix Epoch. Default: The current time is used.
* `nsecs` – (Number between 0-9999) additional time, in 100-nanosecond units. Ignored if `msecs` is unspecified. Default: internal uuid counter is used, as per 4.2.1.2.
* `buffer` – (Array | Buffer) Array or buffer where UUID bytes are to be written.
* `offset` – (Number) Starting index in `buffer` at which to begin writing.
Returns `buffer`, if specified, otherwise the string form of the UUID
Note: The
Example: Generate string UUID with fully-specified options
“`javascript –run v1
const v1options = {
node: [0x01, 0x23, 0x45, 0x67, 0x89, 0xab],
clockseq: 0x1234,
msecs: new Date(‘2011-11-01’).getTime(),
nsecs: 5678
};
uuidv1(v1options); // RESULT
“`
Example: In-place generation of two binary IDs
“`javascript –run v1
// Generate two ids in an array
const arr = new Array();
uuidv1(null, arr, 0); // RESULT
uuidv1(null, arr, 16); // RESULT
“`
### Version 3
“`javascript
const uuidv3 = require(‘uuid/v3’);
// Incantations
uuidv3(name, namespace);
uuidv3(name, namespace, buffer);
uuidv3(name, namespace, buffer, offset);
“`
Generate and return a RFC4122 v3 UUID.
* `name` – (String | Array[]) “name” to create UUID with
* `namespace` – (String | Array[]) “namespace” UUID either as a String or Array[16] of byte values
* `buffer` – (Array | Buffer) Array or buffer where UUID bytes are to be written.
* `offset` – (Number) Starting index in `buffer` at which to begin writing. Default = 0
Returns `buffer`, if specified, otherwise the string form of the UUID
Example:
“`javascript –run v3
uuidv3(‘hello world’, MY_NAMESPACE); // RESULT
“`
### Version 4
“`javascript
const uuidv4 = require(‘uuid/v4’)
// Incantations
uuidv4();
uuidv4(options);
uuidv4(options, buffer, offset);
“`
Generate and return a RFC4122 v4 UUID.
* `options` – (Object) Optional uuid state to apply. Properties may include:
* `random` – (Number[16]) Array of 16 numbers (0-255) to use in place of randomly generated values
* `rng` – (Function) Random # generator function that returns an Array[16] of byte values (0-255)
* `buffer` – (Array | Buffer) Array or buffer where UUID bytes are to be written.
* `offset` – (Number) Starting index in `buffer` at which to begin writing.
Returns `buffer`, if specified, otherwise the string form of the UUID
Example: Generate string UUID with predefined `random` values
“`javascript –run v4
const v4options = {
random: [
0x10, 0x91, 0x56, 0xbe, 0xc4, 0xfb, 0xc1, 0xea,
0x71, 0xb4, 0xef, 0xe1, 0x67, 0x1c, 0x58, 0x36
]
};
uuidv4(v4options); // RESULT
“`
Example: Generate two IDs in a single buffer
“`javascript –run v4
const buffer = new Array();
uuidv4(null, buffer, 0); // RESULT
uuidv4(null, buffer, 16); // RESULT
“`
### Version 5
“`javascript
const uuidv5 = require(‘uuid/v5’);
// Incantations
uuidv5(name, namespace);
uuidv5(name, namespace, buffer);
uuidv5(name, namespace, buffer, offset);
“`
Generate and return a RFC4122 v5 UUID.
* `name` – (String | Array[]) “name” to create UUID with
* `namespace` – (String | Array[]) “namespace” UUID either as a String or Array[16] of byte values
* `buffer` – (Array | Buffer) Array or buffer where UUID bytes are to be written.
* `offset` – (Number) Starting index in `buffer` at which to begin writing. Default = 0
Returns `buffer`, if specified, otherwise the string form of the UUID
Example:
“`javascript –run v5
uuidv5(‘hello world’, MY_NAMESPACE); // RESULT
“`
## Command Line
UUIDs can be generated from the command line with the `uuid` command.
“`shell
$ uuid
ddeb27fb-d9a0-4624-be4d-4615062daed4
$ uuid v1
02d37060-d446-11e7-a9fa-7bdae751ebe1
“`
Type `uuid –help` for usage details
## Testing
“`shell
npm test
“`