[javascript] Copy folder recursively in Node.js

Is there an easier way to copy a folder and all its content without manually doing a sequence of fs.readir, fs.readfile, fs.writefile recursively?

I am just wondering if I'm missing a function which would ideally work like this:

fs.copy("/path/to/source/folder", "/path/to/destination/folder");

This is how I would do it personally:

function copyFolderSync(from, to) {
    fs.mkdirSync(to);
    fs.readdirSync(from).forEach(element => {
        if (fs.lstatSync(path.join(from, element)).isFile()) {
            fs.copyFileSync(path.join(from, element), path.join(to, element));
        } else {
            copyFolderSync(path.join(from, element), path.join(to, element));
        }
    });
}

It works for folders and files.

You can use the ncp module. I think this is what you need.

Since I'm just building a simple Node.js script, I didn't want the users of the script to need to import a bunch of external modules and dependencies, so I put on my thinking cap and did a search for running commands from the Bash shell.

This Node.js code snippet recursively copies a folder called node-webkit.app to a folder called build:

child = exec("cp -r node-webkit.app build", function(error, stdout, stderr) {
    sys.print("stdout: " + stdout);
    sys.print("stderr: " + stderr);
    if(error !== null) {
        console.log("exec error: " + error);
    } else {

    }
});

Thanks to Lance Pollard at dzone for getting me started.

The above snippet is limited to Unix-based platforms, like macOS and Linux, but a similar technique may work for Windows.

This is my approach to solve this problem without any extra modules. Just using the built-in fs and path modules.

Note: This does use the read / write functions of fs, so it does not copy any meta data (time of creation, etc.). As of Node.js 8.5 there is a copyFileSync function available which calls the OS copy functions and therefore also copies meta data. I did not test them yet, but it should work to just replace them. (See https://nodejs.org/api/fs.html#fs_fs_copyfilesync_src_dest_flags)

var fs = require('fs');
var path = require('path');

function copyFileSync( source, target ) {

    var targetFile = target;

    // If target is a directory, a new file with the same name will be created
    if ( fs.existsSync( target ) ) {
        if ( fs.lstatSync( target ).isDirectory() ) {
            targetFile = path.join( target, path.basename( source ) );
        }
    }

    fs.writeFileSync(targetFile, fs.readFileSync(source));
}

function copyFolderRecursiveSync( source, target ) {
    var files = [];

    // Check if folder needs to be created or integrated
    var targetFolder = path.join( target, path.basename( source ) );
    if ( !fs.existsSync( targetFolder ) ) {
        fs.mkdirSync( targetFolder );
    }

    // Copy
    if ( fs.lstatSync( source ).isDirectory() ) {
        files = fs.readdirSync( source );
        files.forEach( function ( file ) {
            var curSource = path.join( source, file );
            if ( fs.lstatSync( curSource ).isDirectory() ) {
                copyFolderRecursiveSync( curSource, targetFolder );
            } else {
                copyFileSync( curSource, targetFolder );
            }
        } );
    }
}

ncp locks the file descriptor and fires a callback when it hasn't been unlocked yet.

I recommend to use the recursive-copy module instead. It supports events and you can be sure in the copy ending.

Mallikarjun M, thank you!

fs-extra did the thing and it can even return a Promise if you do not provide a callback! :)

const path = require('path')
const fs = require('fs-extra')

let source = path.resolve( __dirname, 'folderA')
let destination = path.resolve( __dirname, 'folderB')

fs.copy(source, destination)
  .then(() => console.log('Copy completed!'))
  .catch( err => {
    console.log('An error occurred while copying the folder.')
    return console.error(err)
  })

This is pretty easy with Node.js 10:

const FSP = require('fs').promises;

async function copyDir(src,dest) {
    const entries = await FSP.readdir(src, {withFileTypes: true});
    await FSP.mkdir(dest);
    for(let entry of entries) {
        const srcPath = Path.join(src, entry.name);
        const destPath = Path.join(dest, entry.name);
        if(entry.isDirectory()) {
            await copyDir(srcPath, destPath);
        } else {
            await FSP.copyFile(srcPath, destPath);
        }
    }
}

This assumes dest does not exist.

Here's a function that recursively copies a directory and its contents to another directory:

const fs = require("fs")
const path = require("path")

/**
 * Look ma, it's cp -R.
 * @param {string} src  The path to the thing to copy.
 * @param {string} dest The path to the new copy.
 */
var copyRecursiveSync = function(src, dest) {
  var exists = fs.existsSync(src);
  var stats = exists && fs.statSync(src);
  var isDirectory = exists && stats.isDirectory();
  if (isDirectory) {
    fs.mkdirSync(dest);
    fs.readdirSync(src).forEach(function(childItemName) {
      copyRecursiveSync(path.join(src, childItemName),
                        path.join(dest, childItemName));
    });
  } else {
    fs.copyFileSync(src, dest);
  }
};

There are some modules that support copying folders with their content. The most popular would be wrench.js:

// Deep-copy an existing directory
wrench.copyDirSyncRecursive('directory_to_copy', 'location_where_copy_should_end_up');

An alternative would be node-fs-extra:

fs.copy('/tmp/mydir', '/tmp/mynewdir', function (err) {
  if (err) {
    console.error(err);
  } else {
    console.log("success!");
  }
}); // Copies directory, even if it has subdirectories or files

fs-extra worked for me when ncp and wrench fell short:

https://www.npmjs.com/package/fs-extra

This is how I did it:

let fs = require('fs');
let path = require('path');

Then:

let filePath = // Your file path

let fileList = []
    var walkSync = function(filePath, filelist)
    {
        let files = fs.readdirSync(filePath);
        filelist = filelist || [];
        files.forEach(function(file)
        {
            if (fs.statSync(path.join(filePath, file)).isDirectory())
            {
                filelist = walkSync(path.join(filePath, file), filelist);
            }
            else
            {
                filelist.push(path.join(filePath, file));
            }
        });

        // Ignore hidden files
        filelist = filelist.filter(item => !(/(^|\/)\.[^\/\.]/g).test(item));

        return filelist;
    };

Then call the method:

This.walkSync(filePath, fileList)

I tried fs-extra and copy-dir to copy-folder-recursively. but I want it to

1. work normally (copy-dir throws an unreasonable error)
2. provide two arguments in filter: filepath and filetype (fs-extra does't tell filetype)
3. have a dir-to-subdir check and a dir-to-file check

So I wrote my own:

// Node.js module for Node.js 8.6+
var path = require("path");
var fs = require("fs");

function copyDirSync(src, dest, options) {
  var srcPath = path.resolve(src);
  var destPath = path.resolve(dest);
  if(path.relative(srcPath, destPath).charAt(0) != ".")
    throw new Error("dest path must be out of src path");
  var settings = Object.assign(Object.create(copyDirSync.options), options);
  copyDirSync0(srcPath, destPath, settings);
  function copyDirSync0(srcPath, destPath, settings) {
    var files = fs.readdirSync(srcPath);
    if (!fs.existsSync(destPath)) {
      fs.mkdirSync(destPath);
    }else if(!fs.lstatSync(destPath).isDirectory()) {
      if(settings.overwrite)
        throw new Error(`Cannot overwrite non-directory '${destPath}' with directory '${srcPath}'.`);
      return;
    }
    files.forEach(function(filename) {
      var childSrcPath = path.join(srcPath, filename);
      var childDestPath = path.join(destPath, filename);
      var type = fs.lstatSync(childSrcPath).isDirectory() ? "directory" : "file";
      if(!settings.filter(childSrcPath, type))
        return;
      if (type == "directory") {
        copyDirSync0(childSrcPath, childDestPath, settings);
      } else {
        fs.copyFileSync(childSrcPath, childDestPath, settings.overwrite ? 0 : fs.constants.COPYFILE_EXCL);
        if(!settings.preserveFileDate)
          fs.futimesSync(childDestPath, Date.now(), Date.now());
      }
    });
  }
}
copyDirSync.options = {
  overwrite: true,
  preserveFileDate: true,
  filter: function(filepath, type) {
    return true;
  }
};

And a similar function, mkdirs, which is an alternative to mkdirp:

function mkdirsSync(dest) {
  var destPath = path.resolve(dest);
  mkdirsSync0(destPath);
  function mkdirsSync0(destPath) {
    var parentPath = path.dirname(destPath);
    if(parentPath == destPath)
      throw new Error(`cannot mkdir ${destPath}, invalid root`);
    if (!fs.existsSync(destPath)) {
      mkdirsSync0(parentPath);
      fs.mkdirSync(destPath);
    }else if(!fs.lstatSync(destPath).isDirectory()) {
      throw new Error(`cannot mkdir ${destPath}, a file already exists there`);
    }
  }
}

The one with symbolic link support:

import path from "path"
import {
  existsSync, mkdirSync, readdirSync, lstatSync,
  copyFileSync, symlinkSync, readlinkSync
} from "fs"


export function copyFolderSync(src, dest) {
  if (!existsSync(dest)) mkdirSync(dest)

  readdirSync(src).forEach(dirent => {
    const [srcPath, destPath] = [src, dest].map(dirPath => path.join(dirPath, dirent))
    const stat = lstatSync(srcPath)

    switch (true) {
      case stat.isFile():
        copyFileSync(srcPath, destPath); break
      case stat.isDirectory():
        copyFolderSync(srcPath, destPath); break
      case stat.isSymbolicLink():
        symlinkSync(readlinkSync(srcPath), destPath); break
    }
  })
}

The fs-extra module works like a charm.

Install fs-extra:

$ npm install fs-extra

The following is the program to copy a source directory to a destination directory.

// Include the fs-extra package
var fs = require("fs-extra");

var source = 'folderA'
var destination = 'folderB'

// Copy the source folder to the destination
fs.copy(source, destination, function (err) {
    if (err){
        console.log('An error occurred while copying the folder.')
        return console.error(err)
    }
    console.log('Copy completed!')
});

References

fs-extra: https://www.npmjs.com/package/fs-extra

Example: Node.js Tutorial - Node.js Copy a Folder

The easiest approach for this problem is to use only the 'fs' and 'Path' module and some logic...

All files in the root folder copy with the new name if you want to just set the version number, i.e., " var v = 'Your Directory Name'"

In the file name prefix with content added with the file name.

var fs = require('fs-extra');
var path = require('path');

var c = 0;
var i = 0;
var v = "1.0.2";
var copyCounter = 0;
var directoryCounter = 0;
var directoryMakerCounter = 0;
var recursionCounter = -1;
var Flag = false;
var directoryPath = [];
var directoryName = [];
var directoryFileName = [];
var fileName;
var directoryNameStorer;
var dc = 0;
var route;

if (!fs.existsSync(v)) {
    fs.mkdirSync(v);
}

var basePath = path.join(__dirname, v);


function walk(dir) {

    fs.readdir(dir, function(err, items) {

        items.forEach(function(file) {

            file = path.resolve(dir, file);

            fs.stat(file, function(err, stat) {

                if(stat && stat.isDirectory()) {
                    directoryNameStorer = path.basename(file);
                    route = file;
                    route = route.replace("gd", v);

                    directoryFileName[directoryCounter] = route;
                    directoryPath[directoryCounter] = file;
                    directoryName[directoryCounter] = directoryNameStorer;

                    directoryCounter++;
                    dc++;

                    if (!fs.existsSync(basePath + "/" + directoryName[directoryMakerCounter])) {
                        fs.mkdirSync(directoryFileName[directoryMakerCounter]);
                        directoryMakerCounter++;
                    }
                }
                else {
                    fileName = path.basename(file);
                    if(recursionCounter >= 0) {
                        fs.copyFileSync(file, directoryFileName[recursionCounter] + "/" + v + "_" + fileName, err => {
                            if(err) return console.error(err);
                        });
                        copyCounter++;
                    }
                    else {
                        fs.copyFileSync(file, v + "/" + v + "_" + fileName, err => {
                            if(err) return console.error(err);
                        });
                        copyCounter++;
                    }
                }
                if(copyCounter + dc == items.length && directoryCounter > 0 && recursionCounter < directoryMakerCounter-1) {
                    console.log("COPY COUNTER:             " + copyCounter);
                    console.log("DC COUNTER:               " + dc);
                    recursionCounter++;
                    dc = 0;
                    copyCounter = 0;
                    console.log("ITEM DOT LENGTH:          " + items.length);
                    console.log("RECURSION COUNTER:        " + recursionCounter);
                    console.log("DIRECOTRY MAKER COUNTER:  " + directoryMakerCounter);
                    console.log(": START RECURSION:        " + directoryPath[recursionCounter]);
                    walk(directoryPath[recursionCounter]); //recursive call to copy sub-folder
                }
            })
        })
    });
}

walk('./gd', function(err, data) { // Just pass the root directory which you want to copy
    if(err)
        throw err;
    console.log("done");
})

If you want to copy all contents of source directory recursively then you need to pass recursive option as true and try catch is documented way by fs-extra for sync

As fs-extra is complete replacement of fs so you don't need to import the base module

const fs = require('fs-extra');
let sourceDir = '/tmp/src_dir';
let destDir = '/tmp/dest_dir';
try {
  fs.copySync(sourceDir, destDir, { recursive: true })
  console.log('success!')
} catch (err) {
  console.error(err)
}

I know so many answers are already here, but no one answered it in a simple way.

Regarding fs-exra official documentation, you can do it very easy.

const fs = require('fs-extra')

// Copy file
fs.copySync('/tmp/myfile', '/tmp/mynewfile')

// Copy directory, even if it has subdirectories or files
fs.copySync('/tmp/mydir', '/tmp/mynewdir')

If you are on Linux, and performance is not an issue, you may use the exec function from child_process module, to execute a Bash command:

const { exec } = require('child_process');
exec('cp -r source dest', (error, stdout, stderr) => {...});

In some cases, I found this solution cleaner than downloading an entire module or even using the fs module.

I created a small working example that copies a source folder to another destination folder in just a few steps (based on shift66's answer using ncp):

Step 1 - Install ncp module:

npm install ncp --save

Step 2 - create copy.js (modify the srcPath and destPath variables to whatever you need):

var path = require('path');
var ncp = require('ncp').ncp;

ncp.limit = 16;

var srcPath = path.dirname(require.main.filename); // Current folder
var destPath = '/path/to/destination/folder'; // Any destination folder

console.log('Copying files...');
ncp(srcPath, destPath, function (err) {
  if (err) {
    return console.error(err);
  }
  console.log('Copying files complete.');
});

Step 3 - run

node copy.js

Use shelljs

npm i -D shelljs

const bash = require('shelljs');
bash.cp("-rf", "/path/to/source/folder", "/path/to/destination/folder");

I wrote this function for both copying (copyFileSync) or moving (renameSync) files recursively between directories:

// Copy files
copyDirectoryRecursiveSync(sourceDir, targetDir);
// Move files
copyDirectoryRecursiveSync(sourceDir, targetDir, true);


function copyDirectoryRecursiveSync(source, target, move) {
    if (!fs.lstatSync(source).isDirectory())
        return;

    var operation = move ? fs.renameSync : fs.copyFileSync;
    fs.readdirSync(source).forEach(function (itemName) {
        var sourcePath = path.join(source, itemName);
        var targetPath = path.join(target, itemName);

        if (fs.lstatSync(sourcePath).isDirectory()) {
            fs.mkdirSync(targetPath);
            copyDirectoryRecursiveSync(sourcePath, targetDir);
        }
        else {
            operation(sourcePath, targetPath);
        }
    });
}

For a Linux/Unix OS, you can use the shell syntax

const shell = require('child_process').execSync;

const src = `/path/src`;
const dist = `/path/dist`;

shell(`mkdir -p ${dist}`);
shell(`cp -r ${src}/* ${dist}`);

That's it!

Yes, ncp is cool though...

You might want/should promisify its function to make it super cool. While you're at it, add it to a tools file to reuse it.

Below is a working version which is Async and uses Promises.

File index.js

const {copyFolder} = require('./tools/');

return copyFolder(
    yourSourcePath,
    yourDestinationPath
)
.then(() => {
    console.log('-> Backup completed.')
}) .catch((err) => {
    console.log("-> [ERR] Could not copy the folder: ", err);
})

File tools.js

const ncp = require("ncp");

/**
 * Promise Version of ncp.ncp()
 *
 * This function promisifies ncp.ncp().
 * We take the asynchronous function ncp.ncp() with
 * callback semantics and derive from it a new function with
 * promise semantics.
 */
ncp.ncpAsync = function (sourcePath, destinationPath) {
  return new Promise(function (resolve, reject) {
      try {
          ncp.ncp(sourcePath, destinationPath, function(err){
              if (err) reject(err); else resolve();
          });
      } catch (err) {
          reject(err);
      }
  });
};

/**
 * Utility function to copy folders asynchronously using
 * the Promise returned by ncp.ncp().
 */
const copyFolder = (sourcePath, destinationPath) => {
    return ncp.ncpAsync(sourcePath, destinationPath, function (err) {
        if (err) {
            return console.error(err);
        }
    });
}
module.exports.copyFolder = copyFolder;

This code will work just fine, recursively copying any folder to any location. But it is Windows only.

var child = require("child_process");
function copySync(from, to){
    from = from.replace(/\//gim, "\\");
    to = to.replace(/\//gim, "\\");
    child.exec("xcopy /y /q \"" + from + "\\*\" \"" + to + "\\\"");
}

It works perfectly for my textbased game for creating new players.

Be careful when picking your package. Some packages like copy-dir does not support copying large files more than 0X1FFFFFE8 characters (about 537 MB) long.

It will throw some error like:

buffer.js:630 Uncaught Error: Cannot create a string longer than 0x1fffffe8 characters

I have experienced something like this in one of my projects. Ultimately, I had to change the package I was using and adjust a lot of code. I would say that this is not a very pleasant experience.

If multiple source and multiple destination copies are desired, you can use better-copy and write something like this:

// Copy from multiple source into a directory
bCopy(['/path/to/your/folder1', '/path/to/some/file.txt'], '/path/to/destination/folder');

Or even:

// Copy from multiple source into multiple destination
bCopy(['/path/to/your/folder1', '/path/to/some/file.txt'], ['/path/to/destination/folder', '/path/to/another/folder']);