Node.js - klaw ============== JavaScript Standard Style A Node.js file system walker extracted from [fs-extra](https://github.com/jprichardson/node-fs-extra). [![npm Package](https://img.shields.io/npm/v/klaw.svg?style=flat-square)](https://www.npmjs.org/package/klaw) [![build status](https://api.travis-ci.org/jprichardson/node-klaw.svg)](http://travis-ci.org/jprichardson/node-klaw) [![windows build status](https://ci.appveyor.com/api/projects/status/github/jprichardson/node-klaw?branch=master&svg=true)](https://ci.appveyor.com/project/jprichardson/node-klaw/branch/master) Install ------- npm i --save klaw If you're using Typescript, we've got [types](https://github.com/DefinitelyTyped/DefinitelyTyped/pull/11492/files): npm i --save-dev @types/klaw Name ---- `klaw` is `walk` backwards :p Sync ---- If you need the same functionality but synchronous, you can use [klaw-sync](https://github.com/manidlou/node-klaw-sync). Usage ----- ### klaw(directory, [options]) Returns a [Readable stream](https://nodejs.org/api/stream.html#stream_class_stream_readable) that iterates through every file and directory starting with `dir` as the root. Every `read()` or `data` event returns an object with two properties: `path` and `stats`. `path` is the full path of the file and `stats` is an instance of [fs.Stats](https://nodejs.org/api/fs.html#fs_class_fs_stats). - `directory`: The directory to recursively walk. Type `string`. - `options`: [Readable stream options](https://nodejs.org/api/stream.html#stream_new_stream_readable_options) and the following: - `queueMethod` (`string`, default: `'shift'`): Either `'shift'` or `'pop'`. On `readdir()` array, call either `shift()` or `pop()`. - `pathSorter` (`function`, default: `undefined`): Sorting [function for Arrays](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort). - `fs` (`object`, default: [`graceful-fs`](https://github.com/isaacs/node-graceful-fs)): Use this to hook into the `fs` methods or to use [`mock-fs`](https://github.com/tschaub/mock-fs) - `filter` (`function`, default: `undefined`): Filtering [function for Arrays](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter) - `depthLimit` (`number`, default: `undefined`): The number of times to recurse before stopping. -1 for unlimited. - `preserveSymlinks` (`boolean`, default: `false`): Whether symlinks should be followed or treated as items themselves. If true, symlinks will be returned as items in their own right. If false, the linked item will be returned and potentially recursed into, in its stead. **Streams 1 (push) example:** ```js const klaw = require('klaw') const items = [] // files, directories, symlinks, etc klaw('/some/dir') .on('data', item => items.push(item.path)) .on('end', () => console.dir(items)) // => [ ... array of files] ``` **Streams 2 & 3 (pull) example:** ```js const klaw = require('klaw') const items = [] // files, directories, symlinks, etc klaw('/some/dir') .on('readable', function () { let item while ((item = this.read())) { items.push(item.path) } }) .on('end', () => console.dir(items)) // => [ ... array of files] ``` ### Error Handling Listen for the `error` event. Example: ```js const klaw = require('klaw') klaw('/some/dir') .on('readable', function () { let item while ((item = this.read())) { // do something with the file } }) .on('error', (err, item) => { console.log(err.message) console.log(item.path) // the file the error occurred on }) .on('end', () => console.dir(items)) // => [ ... array of files] ``` ### Aggregation / Filtering / Executing Actions (Through Streams) On many occasions you may want to filter files based upon size, extension, etc. Or you may want to aggregate stats on certain file types. Or maybe you want to perform an action on certain file types. You should use the module [`through2`](https://www.npmjs.com/package/through2) to easily accomplish this. Install `through2`: npm i --save through2 **Example (skipping directories):** ```js const klaw = require('klaw') const through2 = require('through2') const excludeDirFilter = through2.obj(function (item, enc, next) { if (!item.stats.isDirectory()) this.push(item) next() }) const items = [] // files, directories, symlinks, etc klaw('/some/dir') .pipe(excludeDirFilter) .on('data', item => items.push(item.path)) .on('end', () => console.dir(items)) // => [ ... array of files without directories] ``` **Example (ignore hidden directories):** ```js const klaw = require('klaw') const path = require('path') const filterFunc = item => { const basename = path.basename(item) return basename === '.' || basename[0] !== '.' } klaw('/some/dir', { filter: filterFunc }) .on('data', item => { // only items of none hidden folders will reach here }) ``` **Example (totaling size of PNG files):** ```js const klaw = require('klaw') const path = require('path') const through2 = require('through2') let totalPngsInBytes = 0 const aggregatePngSize = through2.obj(function (item, enc, next) { if (path.extname(item.path) === '.png') { totalPngsInBytes += item.stats.size } this.push(item) next() }) klaw('/some/dir') .pipe(aggregatePngSize) .on('data', item => items.push(item.path)) .on('end', () => console.dir(totalPngsInBytes)) // => total of all pngs (bytes) ``` **Example (deleting all .tmp files):** ```js const fs = require('fs') const klaw = require('klaw') const through2 = require('through2') const deleteAction = through2.obj(function (item, enc, next) { this.push(item) if (path.extname(item.path) === '.tmp') { item.deleted = true fs.unlink(item.path, next) } else { item.deleted = false next() } }) const deletedFiles = [] klaw('/some/dir') .pipe(deleteAction) .on('data', item => { if (!item.deleted) return deletedFiles.push(item.path) }) .on('end', () => console.dir(deletedFiles)) // => all deleted files ``` You can even chain a bunch of these filters and aggregators together. By using multiple pipes. **Example (using multiple filters / aggregators):** ```js klaw('/some/dir') .pipe(filterCertainFiles) .pipe(deleteSomeOtherFiles) .on('end', () => console.log('all done!')) ``` **Example passing (piping) through errors:** Node.js does not `pipe()` errors. This means that the error on one stream, like `klaw` will not pipe through to the next. If you want to do this, do the following: ```js const klaw = require('klaw') const through2 = require('through2') const excludeDirFilter = through2.obj(function (item, enc, next) { if (!item.stats.isDirectory()) this.push(item) next() }) const items = [] // files, directories, symlinks, etc klaw('/some/dir') .on('error', err => excludeDirFilter.emit('error', err)) // forward the error on .pipe(excludeDirFilter) .on('data', item => items.push(item.path)) .on('end', () => console.dir(items)) // => [ ... array of files without directories] ``` ### Searching Strategy Pass in options for `queueMethod`, `pathSorter`, and `depthLimit` to affect how the file system is recursively iterated. See the code for more details, it's less than 50 lines :) License ------- MIT Copyright (c) 2015 [JP Richardson](https://github.com/jprichardson)