README.md
1 # posix-character-classes [](https://www.npmjs.com/package/posix-character-classes) [](https://npmjs.org/package/posix-character-classes) [](https://npmjs.org/package/posix-character-classes) [](https://travis-ci.org/jonschlinkert/posix-character-classes) 2 3 > POSIX character classes for creating regular expressions. 4 5 ## Install 6 7 Install with [npm](https://www.npmjs.com/): 8 9 ```sh 10 $ npm install --save posix-character-classes 11 ``` 12 13 Install with [yarn](https://yarnpkg.com): 14 15 ```sh 16 $ yarn add posix-character-classes 17 ``` 18 19 ## Usage 20 21 ```js 22 var posix = require('posix-character-classes'); 23 console.log(posix.alpha); 24 //=> 'A-Za-z' 25 ``` 26 27 ## POSIX Character classes 28 29 The POSIX standard supports the following classes or categories of charactersh (note that classes must be defined within brackets)<sup class="footnote-ref"><a href="#fn1" id="fnref1">[1]</a></sup>: 30 31 | **POSIX class** | **Equivalent to** | **Matches** | 32 | --- | --- | --- | 33 | `[:alnum:]` | `[A-Za-z0-9]` | digits, uppercase and lowercase letters | 34 | `[:alpha:]` | `[A-Za-z]` | upper- and lowercase letters | 35 | `[:ascii:]` | `[\x00-\x7F]` | ASCII characters | 36 | `[:blank:]` | `[ \t]` | space and TAB characters only | 37 | `[:cntrl:]` | `[\x00-\x1F\x7F]` | Control characters | 38 | `[:digit:]` | `[0-9]` | digits | 39 | `[:graph:]` | `[^[:cntrl:]]` | graphic characters (all characters which have graphic representation) | 40 | `[:lower:]` | `[a-z]` | lowercase letters | 41 | `[:print:]` | `[[:graph] ]` | graphic characters and space | 42 | `[:punct:]` | ``[-!"#$%&'()*+,./:;<=>?@[]^_`{ | }~]`` | all punctuation characters (all graphic characters except letters and digits) | 43 | `[:space:]` | `[ \t\n\r\f\v]` | all blank (whitespace) characters, including spaces, tabs, new lines, carriage returns, form feeds, and vertical tabs | 44 | `[:upper:]` | `[A-Z]` | uppercase letters | 45 | `[:word:]` | `[A-Za-z0-9_]` | word characters | 46 | `[:xdigit:]` | `[0-9A-Fa-f]` | hexadecimal digits | 47 48 ## Examples 49 50 * `a[[:digit:]]b` matches `a0b`, `a1b`, ..., `a9b`. 51 * `a[:digit:]b` is invalid, character classes must be enclosed in brackets 52 * `[[:digit:]abc]` matches any digit, as well as `a`, `b`, and `c`. 53 * `[abc[:digit:]]` is the same as the previous, matching any digit, as well as `a`, `b`, and `c` 54 * `[^ABZ[:lower:]]` matches any character except lowercase letters, `A`, `B`, and `Z`. 55 56 ## About 57 58 ### Contributing 59 60 Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](../../issues/new). 61 62 ### Building docs 63 64 _(This project's readme.md is generated by [verb](https://github.com/verbose/verb-generate-readme), please don't edit the readme directly. Any changes to the readme must be made in the [.verb.md](.verb.md) readme template.)_ 65 66 To generate the readme, run the following command: 67 68 ```sh 69 $ npm install -g verbose/verb#dev verb-generate-readme && verb 70 ``` 71 72 ### Running tests 73 74 Running and reviewing unit tests is a great way to get familiarized with a library and its API. You can install dependencies and run tests with the following command: 75 76 ```sh 77 $ npm install && npm test 78 ``` 79 80 ### Author 81 82 **Jon Schlinkert** 83 84 * [github/jonschlinkert](https://github.com/jonschlinkert) 85 * [twitter/jonschlinkert](https://twitter.com/jonschlinkert) 86 87 ### License 88 89 Copyright © 2017, [Jon Schlinkert](https://github.com/jonschlinkert). 90 Released under the [MIT License](LICENSE). 91 92 *** 93 94 _This file was generated by [verb-generate-readme](https://github.com/verbose/verb-generate-readme), v0.5.0, on April 20, 2017._ 95 96 <hr class="footnotes-sep"> 97 <section class="footnotes"> 98 <ol class="footnotes-list"> 99 <li id="fn1" class="footnote-item">table and examples are based on the WikiBooks page for [Regular Expressions/POSIX Basic Regular Expressions](https://en.wikibooks.org/wiki/Regular_Expressions/POSIX_Basic_Regular_Expressions), which is available under the [Creative Commons Attribution-ShareAlike License](https://creativecommons.org/licenses/by-sa/3.0/). <a href="#fnref1" class="footnote-backref">↩</a> 100 101 </li> 102 </ol> 103 </section>