readdir-glob

What is readdir-glob?

The readdir-glob npm package is designed to read directories and list files in them, potentially filtering by patterns using glob syntax. It combines the functionality of reading directories recursively (like `fs.readdir` or `fs.readdirSync` but with support for deep traversal) and filtering files using glob patterns, which specify sets of filenames with wildcard characters.

What are readdir-glob's main functionalities?

Reading directories with glob patterns

This feature allows you to read through directories and subdirectories to find files that match a specific glob pattern. In the provided code sample, `readdir-glob` is used to find all JavaScript files (`**/*.js`) in the current directory and its subdirectories. Events like 'match' and 'end' are used to handle the found files and the completion of the directory reading process.

const readdirGlob = require('readdir-glob');
const baseDirectory = '.';
const options = { glob: '**/*.js' };

const globber = readdirGlob(baseDirectory, options);
globber.on('match', function(match) {
  console.log('Matched file:', match);
});
globber.on('end', function() {
  console.log('Finished reading directory.');
});

Filtering with negation patterns

This feature demonstrates how to use negation patterns to exclude certain directories or files from the search. In the example, all JavaScript files are matched except those within any `node_modules` directory. This is particularly useful for node.js projects where you might want to ignore dependencies.

const readdirGlob = require('readdir-glob');
const baseDirectory = '.';
const options = { glob: ['**/*.js', '!**/node_modules/**'] };

const globber = readdirGlob(baseDirectory, options);
globber.on('match', function(match) {
  console.log('Matched file:', match);
});
globber.on('end', function() {
  console.log('Finished reading directory.');
});

Other packages similar to readdir-glob

glob

The `glob` package is one of the most popular packages for matching files using the glob syntax. It provides a similar functionality to `readdir-glob` but focuses more on the pattern matching aspect and does not inherently support reading directories in a structured manner like `readdir-glob` does.

fast-glob

Similar to `readdir-glob`, `fast-glob` allows for searching files using glob patterns. It is designed to be faster and more efficient, especially for large file systems. It supports all the basic features of glob syntax and adds some additional options for performance optimization.

node-glob

This package is another alternative that provides glob functionality in Node.js environments. While similar in purpose to `readdir-glob`, `node-glob` focuses more on the globbing aspect and might not offer the same level of directory traversal and reading capabilities.

README

Readdir-Glob

Recursive version of fs.readdir wih stream API and glob filtering. Uses the minimatch library to do its matching.

Requires Node.js 10.0 or later.

Performances

Compared to glob, readdir-glob is memory efficient: no matter the file system size, or the number of returned files, the memory usage is constant.

The CPU cost is proportional to the number of files in root folder, minus the number files in options.skip folders.

Advice: For better performances use options.skip to restrict the search as much as possible.

Usage

Install with npm

npm i readdir-glob

const readdirGlob = require('readdir-glob');
const globber = readdirGlob('.', {pattern: '**/*.js'});
globber.on('match', match => {
    // m.relative: relative path of the matched file
    // m.absolute: absolute path of the matched file
    // m.stat: stat of the matched file (only if stat:true option is used)
});
globber.on('error', err => {
    console.error('fatal error', err);
});
globber.on('end', (m) => {
    console.log('done');
});

readdirGlob(root, [options])

• root {String} Path to be read recursively, default: '.'
• options {Object} Options, default: {}

Returns a EventEmitter reading given root recursively.

Properties

• options: The options object passed in.
• paused: Boolean which is set to true when calling pause().
• aborted Boolean which is set to true when calling abort(). There is no way at this time to continue a glob search after aborting.

Events

• match: Every time a match is found, this is emitted with the specific thing that matched.
• end: When the matching is finished, this is emitted with all the matches found.
• error: Emitted when an unexpected error is encountered.

Methods

• pause(): Temporarily stop the search
• resume(): Resume the search
• abort(): Stop the search forever

Options

• pattern: Glob pattern or Array of Glob patterns to match the found files with. A file has to match at least one of the provided patterns to be returned.
• ignore: Glob pattern or Array of Glob patterns to exclude matches. If a file or a folder matches at least one of the provided patterns, it's not returned. It doesn't prevent files from folder content to be returned. Note: ignore patterns are always in dot:true mode.
• skip: Glob pattern or Array of Glob patterns to exclude folders. If a folder matches one of the provided patterns, it's not returned, and it's not explored: this prevents any of its children to be returned. Note: skip patterns are always in dot:true mode.
• mark: Add a / character to directory matches.
• stat: Set to true to stat all results. This reduces performance.
• silent: When an unusual error is encountered when attempting to read a directory, a warning will be printed to stderr. Set the silent option to true to suppress these warnings.
• nodir: Do not match directories, only files.
• follow: Follow symlinked directories. Note that requires to stat all results, and so reduces performance.

The following options apply only if pattern option is set, and are forwarded to minimatch:

• dot: Allow pattern to match filenames starting with a period, even if the pattern does not explicitly have a period in that spot.
• noglobstar: Disable ** matching against multiple folder names.
• nocase: Perform a case-insensitive match. Note: on case-insensitive filesystems, non-magic patterns will match by default, since stat and readdir will not raise errors.
• matchBase: Perform a basename-only match if the pattern does not contain any slash characters. That is, *.js would be treated as equivalent to **/*.js, matching all js files in all directories.

References

Unit-test set is based on node-glob tests.