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klaw-sync is a Node.js recursive and fast file system walker, which is the synchronous counterpart of klaw. It lists all files and directories inside a directory recursively and returns an array of objects that each object has two properties: path and stats. path is the full path of the file or directory and stats is an instance of fs.Stats.


npm i klaw-sync


klawSync(directory[, options])

  • directory <String>
  • options <Object> (optional)
    • nodir <Boolean> default: undefined
      • return only files (ignore directories).
    • nofile <Boolean> default: undefined
      • return only directories (ignore files).
    • depthLimit: <Number> default: -1
      • the number of times to recurse before stopping. -1 for unlimited.
    • fs: <Object> default: graceful-fs
      • custom fs, useful when mocking fs object.
    • filter <Function> default: undefined
      • function that gets one argument fn({path: '', stats: {}}) and returns true to include or false to exclude the item.
    • traverseAll <Boolean> default: undefined
      • traverse all subdirectories, regardless of filter option. This can be useful when you have a filter function and still want to traverse all subdirectories even if your filter function doesn't pass for some directories.
  • Return: <Array<Object>> [{path: '', stats: {}}]


const klawSync = require('klaw-sync')

const paths = klawSync('/some/dir')
// paths = [{path: '/some/dir/dir1', stats: {}}, {path: '/some/dir/file1', stats: {}}]

catch error

const klawSync = require('klaw-sync')

let paths
try {
  paths = klawSync('/some/dir')
} catch (er) {

files only

const klawSync = require('klaw-sync')

const files = klawSync('/some/dir', {nodir: true})
// files = [{path: '/some/dir/file1', stats: {}}, {path: '/some/dir/file2', stats: {}}]

directories only

const klawSync = require('klaw-sync')

const dirs = klawSync('/some/dir', {nofile: true})
// dirs = [{path: '/some/dir/dir1', stats: {}}, {path: '/some/dir/dir2', stats: {}}]

ignore hidden directories

const path = require('path')
const klawSync = require('klaw-sync')

const filterFn = item => {
  const basename = path.basename(item.path)
  return basename === '.' || basename[0] !== '.'

const paths = klawSync('/some/dir', { filter: filterFn})

filter based on stats

Here traverseAll option is required since we still want to read all subdirectories even if they don't pass the filter function, to see if their contents do pass the filter function.

const klawSync = require('klaw-sync')

const refTime = new Date(2017, 3, 24).getTime()
const filterFn = item => item.stats.mtime.getTime() > refTime

const paths = klawSync('/some/dir', { traverseAll: true, filter: filterFn })

Run tests

lint: npm run lint

unit test: npm run unit

lint & unit: npm test

benchmark: npm run benchmark

Performance compare to other similar modules

Running some benchmark tests on these modules:

(as of Jan 25, 2017) klaw-sync is the fastest module!

results (tested on Ubuntu 18.04, Intel(R) Core(TM) i7-2630QM CPU @ 2.00GHz, 8 CPUs, 8g RAM, node v10.9.0)
Running benchmark tests..

root dir length: 1110
walk-sync x 80.71 ops/sec ±1.42% (72 runs sampled)
klaw-sync x 160 ops/sec ±1.17% (79 runs sampled)
Fastest is klaw-sync

root dir length: 11110
walk-sync x 7.55 ops/sec ±3.39% (23 runs sampled)
klaw-sync x 14.95 ops/sec ±0.27% (40 runs sampled)
Fastest is klaw-sync

root dir length: 111110
walk-sync x 0.63 ops/sec ±6.92% (6 runs sampled)
klaw-sync x 1.22 ops/sec ±0.96% (7 runs sampled)
Fastest is klaw-sync


Licensed under MIT

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