.verb.md
April 7, 2020 · View on GitHub
Usage
var posix = require('{%= name %}');
console.log(posix.alpha);
//=> 'A-Za-z'
POSIX Character classes
The POSIX standard supports the following classes or categories of charactersh (note that classes must be defined within brackets)1:
| POSIX class | Equivalent to | Matches |
|---|---|---|
[:alnum:] | [A-Za-z0-9] | digits, uppercase and lowercase letters |
[:alpha:] | [A-Za-z] | upper- and lowercase letters |
[:ascii:] | [\x00-\x7F] | ASCII characters |
[:blank:] | [ \t] | space and TAB characters only |
[:cntrl:] | [\x00-\x1F\x7F] | Control characters |
[:digit:] | [0-9] | digits |
[:graph:] | [^ [:cntrl:]] | graphic characters (all characters which have graphic representation) |
[:lower:] | [a-z] | lowercase letters |
[:print:] | [[:graph] ] | graphic characters and space |
[:punct:] | ``[-!"#$%&'()*+,./:;<=>?@[]^_`{ | }~]`` |
[:space:] | [ \t\n\r\f\v] | all blank (whitespace) characters, including spaces, tabs, new lines, carriage returns, form feeds, and vertical tabs |
[:upper:] | [A-Z] | uppercase letters |
[:word:] | [A-Za-z0-9_] | word characters |
[:xdigit:] | [0-9A-Fa-f] | hexadecimal digits |
Examples
a[[:digit:]]bmatchesa0b,a1b, ...,a9b.a[:digit:]bis invalid, character classes must be enclosed in brackets[[:digit:]abc]matches any digit, as well asa,b, andc.[abc[:digit:]]is the same as the previous, matching any digit, as well asa,b, andc[^ABZ[:lower:]]matches any character except lowercase letters,A,B, andZ.
Footnotes
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table and examples are based on the WikiBooks page for Regular Expressions/POSIX Basic Regular Expressions, which is available under the Creative Commons Attribution-ShareAlike License. ↩