brace-expansion

brace-expansion

Brace expansion, as known from sh/bash, in JavaScript.

Example

import { expand } from 'brace-expansion'

expand('file-{a,b,c}.jpg')
// => ['file-a.jpg', 'file-b.jpg', 'file-c.jpg']

expand('-v{,,}')
// => ['-v', '-v', '-v']

expand('file{0..2}.jpg')
// => ['file0.jpg', 'file1.jpg', 'file2.jpg']

expand('file-{a..c}.jpg')
// => ['file-a.jpg', 'file-b.jpg', 'file-c.jpg']

expand('file{2..0}.jpg')
// => ['file2.jpg', 'file1.jpg', 'file0.jpg']

expand('file{0..4..2}.jpg')
// => ['file0.jpg', 'file2.jpg', 'file4.jpg']

expand('file-{a..e..2}.jpg')
// => ['file-a.jpg', 'file-c.jpg', 'file-e.jpg']

expand('file{00..10..5}.jpg')
// => ['file00.jpg', 'file05.jpg', 'file10.jpg']

expand('{{A..C},{a..c}}')
// => ['A', 'B', 'C', 'a', 'b', 'c']

expand('ppp{,config,oe{,conf}}')
// => ['ppp', 'pppconfig', 'pppoe', 'pppoeconf']

API

import { expand } from 'brace-expansion'

const expanded = expand(str, [options])

Return an array of all possible and valid expansions of str. If none are found, [str] is returned.

The options object can provide a max value to cap the number of expansions allowed. This is limited to 100_000 by default, to prevent DoS attacks.

const expansions = expand('{1..100}'.repeat(5), {
  max: 100,
})
// expansions.length will be 100, not 100^5

Valid expansions are:

;/^(.*,)+(.+)?$/
// {a,b,...}

A comma separated list of options, like {a,b} or {a,{b,c}} or {,a,}.

;/^-?\d+\.\.-?\d+(\.\.-?\d+)?$/
// {x..y[..incr]}

A numeric sequence from x to y inclusive, with optional increment. If x or y start with a leading 0, all the numbers will be padded to have equal length. Negative numbers and backwards iteration work too.

;/^-?\d+\.\.-?\d+(\.\.-?\d+)?$/
// {x..y[..incr]}

An alphabetic sequence from x to y inclusive, with optional increment. x and y must be exactly one character, and if given, incr must be a number.

For compatibility reasons, the string ${ is not eligible for brace expansion.

Similar packages

Other packages similar to brace-expansion

minimatch

Minimatch is a minimal matching utility that works with patterns similar to those in shell scripting. It is often used for matching file names and provides functionality similar to brace-expansion but with a broader set of pattern matching features.

glob

Glob is a package that allows pattern matching based on the Unix shell's glob syntax. It includes brace expansion as part of its pattern matching capabilities, but it is primarily used for file system operations, such as finding files that match a given pattern.

micromatch

Micromatch is a highly optimized and faster alternative to minimatch and glob. It provides advanced pattern matching with a focus on performance. It supports brace expansion and is often used in build tools and file watchers.