How to create full path with node's fs.mkdirSync? - node.js

I'm trying to create a full path if it doesn't exist.
The code looks like this:
var fs = require('fs');
if (!fs.existsSync(newDest)) fs.mkdirSync(newDest);
This code works great as long as there is only one subdirectory (a newDest like 'dir1') however when there is a directory path like ('dir1/dir2') it fails with
Error: ENOENT, no such file or directory
I'd like to be able to create the full path with as few lines of code as necessary.
I read there is a recursive option on fs and tried it like this
var fs = require('fs');
if (!fs.existsSync(newDest)) fs.mkdirSync(newDest,'0777', true);
I feel like it should be that simple to recursively create a directory that doesn't exist. Am I missing something or do I need to parse the path and check each directory and create it if it doesn't already exist?
I'm pretty new to Node. Maybe I'm using an old version of FS?

Update
NodeJS version 10.12.0 has added a native support for both mkdir and mkdirSync to create a directory recursively with recursive: true option as the following:
fs.mkdirSync(targetDir, { recursive: true });
And if you prefer fs Promises API, you can write
fs.promises.mkdir(targetDir, { recursive: true });
Original Answer
Create directories recursively if they do not exist! (Zero dependencies)
const fs = require('fs');
const path = require('path');
function mkDirByPathSync(targetDir, { isRelativeToScript = false } = {}) {
const sep = path.sep;
const initDir = path.isAbsolute(targetDir) ? sep : '';
const baseDir = isRelativeToScript ? __dirname : '.';
return targetDir.split(sep).reduce((parentDir, childDir) => {
const curDir = path.resolve(baseDir, parentDir, childDir);
try {
fs.mkdirSync(curDir);
} catch (err) {
if (err.code === 'EEXIST') { // curDir already exists!
return curDir;
}
// To avoid `EISDIR` error on Mac and `EACCES`-->`ENOENT` and `EPERM` on Windows.
if (err.code === 'ENOENT') { // Throw the original parentDir error on curDir `ENOENT` failure.
throw new Error(`EACCES: permission denied, mkdir '${parentDir}'`);
}
const caughtErr = ['EACCES', 'EPERM', 'EISDIR'].indexOf(err.code) > -1;
if (!caughtErr || caughtErr && curDir === path.resolve(targetDir)) {
throw err; // Throw if it's just the last created dir.
}
}
return curDir;
}, initDir);
}
Usage
// Default, make directories relative to current working directory.
mkDirByPathSync('path/to/dir');
// Make directories relative to the current script.
mkDirByPathSync('path/to/dir', {isRelativeToScript: true});
// Make directories with an absolute path.
mkDirByPathSync('/path/to/dir');
Demo
Try It!
Explanations
[UPDATE] This solution handles platform-specific errors like EISDIR for Mac and EPERM and EACCES for Windows. Thanks to all the reporting comments by #PediT., #JohnQ, #deed02392, #robyoder and #Almenon.
This solution handles both relative and absolute paths. Thanks to #john comment.
In the case of relative paths, target directories will be created (resolved) in the current working directory. To Resolve them relative to the current script dir, pass {isRelativeToScript: true}.
Using path.sep and path.resolve(), not just / concatenation, to avoid cross-platform issues.
Using fs.mkdirSync and handling the error with try/catch if thrown to handle race conditions: another process may add the file between the calls to fs.existsSync() and fs.mkdirSync() and causes an exception.
The other way to achieve that could be checking if a file exists then creating it, I.e, if (!fs.existsSync(curDir) fs.mkdirSync(curDir);. But this is an anti-pattern that leaves the code vulnerable to race conditions. Thanks to #GershomMaes comment about the directory existence check.
Requires Node v6 and newer to support destructuring. (If you have problems implementing this solution with old Node versions, just leave me a comment)

A more robust answer is to use use mkdirp.
var mkdirp = require('mkdirp');
mkdirp('/path/to/dir', function (err) {
if (err) console.error(err)
else console.log('dir created')
});
Then proceed to write the file into the full path with:
fs.writeFile ('/path/to/dir/file.dat'....

One option is to use shelljs module
npm install shelljs
var shell = require('shelljs');
shell.mkdir('-p', fullPath);
From that page:
Available options:
p: full path (will create intermediate dirs if necessary)
As others have noted, there's other more focused modules. But, outside of mkdirp, it has tons of other useful shell operations (like which, grep etc...) and it works on windows and *nix
Edit: comments suggest this doesn't work on systems that don't have mkdir cli instances. That is not the case. That's the point shelljs - create a portable cross platform set of shell like functions. It works on even windows.

fs-extra adds file system methods that aren't included in the native fs module. It is a drop in replacement for fs.
Install fs-extra
$ npm install --save fs-extra
const fs = require("fs-extra");
// Make sure the output directory is there.
fs.ensureDirSync(newDest);
There are sync and async options.
https://github.com/jprichardson/node-fs-extra/blob/master/docs/ensureDir.md

Using reduce we can verify if each path exists and create it if necessary, also this way I think it is easier to follow. Edited, thanks #Arvin, we should use path.sep to get the proper platform-specific path segment separator.
const path = require('path');
// Path separators could change depending on the platform
const pathToCreate = 'path/to/dir';
pathToCreate
.split(path.sep)
.reduce((prevPath, folder) => {
const currentPath = path.join(prevPath, folder, path.sep);
if (!fs.existsSync(currentPath)){
fs.mkdirSync(currentPath);
}
return currentPath;
}, '');

This feature has been added to node.js in version 10.12.0, so it's as easy as passing an option {recursive: true} as second argument to the fs.mkdir() call.
See the example in the official docs.
No need for external modules or your own implementation.

i know this is an old question, but nodejs v10.12.0 now supports this natively with the recursive option set to true. fs.mkdir
// Creates /tmp/a/apple, regardless of whether `/tmp` and /tmp/a exist.
fs.mkdir('/tmp/a/apple', { recursive: true }, (err) => {
if (err) throw err;
});

Now with NodeJS >= 10.12.0, you can use fs.mkdirSync(path, { recursive: true }) fs.mkdirSync

Example for Windows (no extra dependencies and error handling)
const path = require('path');
const fs = require('fs');
let dir = "C:\\temp\\dir1\\dir2\\dir3";
function createDirRecursively(dir) {
if (!fs.existsSync(dir)) {
createDirRecursively(path.join(dir, ".."));
fs.mkdirSync(dir);
}
}
createDirRecursively(dir); //creates dir1\dir2\dir3 in C:\temp

You can simply check folder exist or not in path recursively and make the folder as you check if they are not present. (NO EXTERNAL LIBRARY)
function checkAndCreateDestinationPath (fileDestination) {
const dirPath = fileDestination.split('/');
dirPath.forEach((element, index) => {
if(!fs.existsSync(dirPath.slice(0, index + 1).join('/'))){
fs.mkdirSync(dirPath.slice(0, index + 1).join('/'));
}
});
}

You can use the next function
const recursiveUpload = (path: string) => {
const paths = path.split("/")
const fullPath = paths.reduce((accumulator, current) => {
fs.mkdirSync(accumulator)
return `${accumulator}/${current}`
})
fs.mkdirSync(fullPath)
return fullPath
}
So what it does:
Create paths variable, where it stores every path by itself as an element of the array.
Adds "/" at the end of each element in the array.
Makes for the cycle:
Creates a directory from the concatenation of array elements which indexes are from 0 to current iteration. Basically, it is recursive.
Hope that helps!
By the way, in Node v10.12.0 you can use recursive path creation by giving it as the additional argument.
fs.mkdir('/tmp/a/apple', { recursive: true }, (err) => {
if (err) throw err;
});
https://nodejs.org/api/fs.html#fs_fs_mkdirsync_path_options

Too many answers, but here's a solution without recursion that works by splitting the path and then left-to-right building it back up again
function mkdirRecursiveSync(path) {
let paths = path.split(path.delimiter);
let fullPath = '';
paths.forEach((path) => {
if (fullPath === '') {
fullPath = path;
} else {
fullPath = fullPath + '/' + path;
}
if (!fs.existsSync(fullPath)) {
fs.mkdirSync(fullPath);
}
});
};
For those concerned about windows vs Linux compatibility, simply replace the forward slash with double backslash '\' in both occurrence above but TBH we are talking about node fs not windows command line and the former is pretty forgiving and the above code will simply work on Windows and is more a complete solution cross platform.

const fs = require('fs');
try {
fs.mkdirSync(path, { recursive: true });
} catch (error) {
// this make script keep running, even when folder already exist
console.log(error);
}

An asynchronous way to create directories recursively:
import fs from 'fs'
const mkdirRecursive = function(path, callback) {
let controlledPaths = []
let paths = path.split(
'/' // Put each path in an array
).filter(
p => p != '.' // Skip root path indicator (.)
).reduce((memo, item) => {
// Previous item prepended to each item so we preserve realpaths
const prevItem = memo.length > 0 ? memo.join('/').replace(/\.\//g, '')+'/' : ''
controlledPaths.push('./'+prevItem+item)
return [...memo, './'+prevItem+item]
}, []).map(dir => {
fs.mkdir(dir, err => {
if (err && err.code != 'EEXIST') throw err
// Delete created directory (or skipped) from controlledPath
controlledPaths.splice(controlledPaths.indexOf(dir), 1)
if (controlledPaths.length === 0) {
return callback()
}
})
})
}
// Usage
mkdirRecursive('./photos/recent', () => {
console.log('Directories created succesfully!')
})

Here's my imperative version of mkdirp for nodejs.
function mkdirSyncP(location) {
let normalizedPath = path.normalize(location);
let parsedPathObj = path.parse(normalizedPath);
let curDir = parsedPathObj.root;
let folders = parsedPathObj.dir.split(path.sep);
folders.push(parsedPathObj.base);
for(let part of folders) {
curDir = path.join(curDir, part);
if (!fs.existsSync(curDir)) {
fs.mkdirSync(curDir);
}
}
}

How about this approach :
if (!fs.existsSync(pathToFile)) {
var dirName = "";
var filePathSplit = pathToFile.split('/');
for (var index = 0; index < filePathSplit.length; index++) {
dirName += filePathSplit[index]+'/';
if (!fs.existsSync(dirName))
fs.mkdirSync(dirName);
}
}
This works for relative path.

Based on mouneer's zero-dependencies answer, here's a slightly more beginner friendly Typescript variant, as a module:
import * as fs from 'fs';
import * as path from 'path';
/**
* Recursively creates directories until `targetDir` is valid.
* #param targetDir target directory path to be created recursively.
* #param isRelative is the provided `targetDir` a relative path?
*/
export function mkdirRecursiveSync(targetDir: string, isRelative = false) {
const sep = path.sep;
const initDir = path.isAbsolute(targetDir) ? sep : '';
const baseDir = isRelative ? __dirname : '.';
targetDir.split(sep).reduce((prevDirPath, dirToCreate) => {
const curDirPathToCreate = path.resolve(baseDir, prevDirPath, dirToCreate);
try {
fs.mkdirSync(curDirPathToCreate);
} catch (err) {
if (err.code !== 'EEXIST') {
throw err;
}
// caught EEXIST error if curDirPathToCreate already existed (not a problem for us).
}
return curDirPathToCreate; // becomes prevDirPath on next call to reduce
}, initDir);
}

As clean as this :)
function makedir(fullpath) {
let destination_split = fullpath.replace('/', '\\').split('\\')
let path_builder = destination_split[0]
$.each(destination_split, function (i, path_segment) {
if (i < 1) return true
path_builder += '\\' + path_segment
if (!fs.existsSync(path_builder)) {
fs.mkdirSync(path_builder)
}
})
}

I had issues with the recursive option of fs.mkdir so I made a function that does the following:
Creates a list of all directories, starting with the final target dir and working up to the root parent.
Creates a new list of needed directories for the mkdir function to work
Makes each directory needed, including the final
function createDirectoryIfNotExistsRecursive(dirname) {
return new Promise((resolve, reject) => {
const fs = require('fs');
var slash = '/';
// backward slashes for windows
if(require('os').platform() === 'win32') {
slash = '\\';
}
// initialize directories with final directory
var directories_backwards = [dirname];
var minimize_dir = dirname;
while (minimize_dir = minimize_dir.substring(0, minimize_dir.lastIndexOf(slash))) {
directories_backwards.push(minimize_dir);
}
var directories_needed = [];
//stop on first directory found
for(const d in directories_backwards) {
if(!(fs.existsSync(directories_backwards[d]))) {
directories_needed.push(directories_backwards[d]);
} else {
break;
}
}
//no directories missing
if(!directories_needed.length) {
return resolve();
}
// make all directories in ascending order
var directories_forwards = directories_needed.reverse();
for(const d in directories_forwards) {
fs.mkdirSync(directories_forwards[d]);
}
return resolve();
});
}

I solved the problem this way - similar to other recursive answers but to me this is much easier to understand and read.
const path = require('path');
const fs = require('fs');
function mkdirRecurse(inputPath) {
if (fs.existsSync(inputPath)) {
return;
}
const basePath = path.dirname(inputPath);
if (fs.existsSync(basePath)) {
fs.mkdirSync(inputPath);
}
mkdirRecurse(basePath);
}

Could not find an example to create dir's with the required permissions.
Create Directories async recursively with the permissions you want.
Heres a plain nodejs solution
node v18.12.1
Ubuntu 18
//-----------------------------
const fs = require('fs');
const fsPromises = fs.promises;
const checkDirAccess = async (userDir) => {
try {
await fsPromises.access(userDir, fs.constants.R_OK | fs.constants.W_OK);
console.log(` ${userDir} Dir existss`);
return userDir;
} catch (err) {
if(err.errno = -2)
return await crDir(userDir);
else
throw err;
}
}
const crDir = async (userDir) => {
try {
let newDir = await fsPromises.mkdir(userDir, { recursive: true, mode: 0o700});
// When userDir is created; newDir = undefined;
console.log(` Created new Dir ${newDir}`);
return newDir;
} catch (err) {
throw err;
}
}
const directoryPath = ['uploads/xvc/xvc/xvc/specs', 'uploads/testDir11', 'uploads/xsXa/', 'uploads//xsb//', 'uploads//xsV/'];
const findDir = async() => {
try {
for (const iterator of directoryPath) {
let dirOK = await checkDirAccess(iterator);
if(dirOK)
console.log(`found ${dirOK}`)
}
} catch (error) {
console.error('Error : ', error);
}
}

Exec can be messy on windows. There is a more "nodie" solution. Fundamentally, you have a recursive call to see if a directory exists and dive into the child (if it does exist) or create it. Here is a function that will create the children and call a function when finished:
fs = require('fs');
makedirs = function(path, func) {
var pth = path.replace(/['\\]+/g, '/');
var els = pth.split('/');
var all = "";
(function insertOne() {
var el = els.splice(0, 1)[0];
if (!fs.existsSync(all + el)) {
fs.mkdirSync(all + el);
}
all += el + "/";
if (els.length == 0) {
func();
} else {
insertOne();
}
})();
}

This version works better on Windows than the top answer because it understands both / and path.sep so that forward slashes work on Windows as they should. Supports absolute and relative paths (relative to the process.cwd).
/**
* Creates a folder and if necessary, parent folders also. Returns true
* if any folders were created. Understands both '/' and path.sep as
* path separators. Doesn't try to create folders that already exist,
* which could cause a permissions error. Gracefully handles the race
* condition if two processes are creating a folder. Throws on error.
* #param targetDir Name of folder to create
*/
export function mkdirSyncRecursive(targetDir) {
if (!fs.existsSync(targetDir)) {
for (var i = targetDir.length-2; i >= 0; i--) {
if (targetDir.charAt(i) == '/' || targetDir.charAt(i) == path.sep) {
mkdirSyncRecursive(targetDir.slice(0, i));
break;
}
}
try {
fs.mkdirSync(targetDir);
return true;
} catch (err) {
if (err.code !== 'EEXIST') throw err;
}
}
return false;
}

Related

How can i catch and handle Error: EEXIST: file already exists, copyfile "somepath" "anotherpath" in nodejs

I want to change the name of file when i get duplicate files while performing copy operation in nodejs using fs module (right now the process exits with error, i want to execute file name change logic on error)
function copyFile(filePath,fileName){
fs.copyFileSync(filePath,
path.join(destination,fileName),fs.constants.COPYFILE_EXCL, (err) => {
if (err) {
fileName= "0"+fileName; //changing the filename
copyFile(filePath,fileName)
}
console.log(fileName+" copied");
})
}
You simply need to check if error.code === 'EEXIST'.
Few notes:
copyFileSync does not accept callback - it's a synchronous function
You're using path.join incorrectly. This utility is used mainly to provide cross-platform paths (Unix - /, Windows - \). If you're concatenating it yourself with / there is no point to use path.join it will not work on non-unix systems anyway.
There is a typo filename -> fileName
You need two fileName... arguments for copyFile function (source and destination), because source file with prepended 0-s not exists by the moment you're calling the function.
const fs = require('fs');
const path = require('path');
const destination = '/tmp/';
function copyFile(filePath, fileNameFrom, fileNameTo=fileNameFrom) {
const from = path.join(filePath, fileNameFrom);
const to = path.join(destination, fileNameTo);
try {
fs.copyFileSync(from, to, fs.constants.COPYFILE_EXCL);
console.log(`${from} copied into ${to}`);
} catch (error) {
console.error(error);
if (error.code === 'EEXIST') {
copyFile(filePath, fileNameFrom, '0' + fileNameTo);
}
}
}
copyFile('/tmp/test', 'a.txt');
Note: do not forget to change destination variable

Why does node.js say invisible files don't exist?

Executing the below function test ()
with Node.js v8.11.2 on my Windows-10
prints out this:
DOES NOT EXIST ? C:\pagefile.sys
DOES NOT EXIST ? C:\hiberfil.sys
DOES NOT EXIST ? C:\swapfile.sys
DOES NOT EXIST ? C:\System Volume Information
These all seem to be invisible system files yes.
But they obviously exist. So why does Node.js
tell me they don't exist? Are there other cases
where file or folder is listed by readdirSync()
yet existsSync() returns false for them?
Is this a feature or bug?
function test ()
{ let Fs = require("fs");
let Path = require("path");
let path = "C:/";
let ents = Fs.readdirSync(path) ;
let dirs = ents.map
( e =>
{ let absPath = Path.join (path, e);
if (! Fs.existsSync(absPath))
{ console.log ("DOES NOT EXIST ? " + absPath)
} else
{ console.log ("DOES EXIST: " + absPath)
}
}
);
}

Renaming multiple files asyncroniosly causing error in Node.js

I am trying to rename a bunch of pre-generated testing files (1000+) asynchronously in Node.js.
The code looks like the following:
const fs = require('fs')
const { each } = require('async')
each(files, file => {
let newfile = 'new' + file
fs.rename(file, newfile, err => {
err ? console.log(err) : console.log('renamed')
}
})
This leads to following error:
Uncaught Error: ENOENT: no such file or directory, lstat '8d3320e35d22772f'
at fs.lstatSync (fs.js:902:18)
at Object.fs.lstatSync
It's not async module issue, since replacing each with native forEach leads to the same error. Also, there are no issues when using synchronous version of rename fs.renameSync.
I think it's trying to move some file twice or so but can't figure where exactly mistake is. Made this assumption, because all files have been already renamed successfully and very likely error generated afterward. Can someone advice what causing such behavior?
My bad. Just in case someone curious, this error came from following underlying function:
function rmDir(dir) {
var list = fs.readdirSync(dir);
for(var i = 0; i < list.length; i++) {
var dirOrFile = path.join(dir, list[i]);
var stat = fs.lstatSync(dirOrFile);
if(dirOrFile == "." || dirOrFile == "..") {
// pass these files
} else if (stat.isDirectory()) {
// rmdir recursively
rmDir(dirOrFile);
}
// else { fs.unlinkSync(dirOrFile) } // rm fiilename
}
fs.rmdirSync(dir);
}

Node.js moving contents of subdirectory into current directory

I have a Node script that downloads a zip into tmp/archive.zip and extracts that to tmp/archive.
I would like to move the contents of tmp/archive into .. I'm having difficulty finding how to use fs.rename in a way that is equivalent to mv tmp/archive/* .
I have tried fs.rename('tmp/archive/*', '.', function(err){ but that gives me the following error: Error: ENOENT: no such file or directory, rename 'tmp/archive/*' -> '.'
I have also tried using glob to list the contents of tmp/archive and then iterate through it and move the files using fs-extra's move, as follows:
glob('tmp/archive/*', {}, function(err, files){
for (var i = files.length - 1; i >= 0; i--) {
fs.move(files[i], '.', function(err){});
}
}.bind(this));
which results in the folowing error: Error: EEXIST: file already exists, link 'tmp/archive/subdirectory' -> '.'
I could just call mv tmp/archive/* . from the script but i would like to avoid that if possible. Is there something obvious I am missing? How can I go about doing this?
Here's one way to move a directory of files from one location to another (assuming they are on the same volume and thus can be renamed rather than copied):
var Promise = require('bluebird');
var fs = Promise.promisifyAll(require('fs'));
var path = require('path');
function moveFiles(srcDir, destDir) {
return fs.readdirAsync(srcDir).map(function(file) {
var destFile = path.join(destDir, file);
console.log(destFile);
return fs.renameAsync(path.join(srcDir, file), destFile).then(function() {
return destFile;
});
});
}
// sample usage:
moveFiles(path.join(".", "tempSource"), path.join(".", "tempDest")).then(function(files) {
// all done here
}).catch(function(err) {
// error here
});
This will move both files and sub-directories in the srcDir to destDir. Since fs.rename() will move a sub-directory all at once, you don't have to traverse recursively.
When designing a function like this, you have a choice of error behavior. The above implementation aborts upon the first error. You could change the implementation to move all files possible and then just return a list of files that could not be moved.
Here's a version that renames all files that it can and if there were any errors, it rejects at the end with a list of the files that failed and their error objects:
function moveFilesAll(srcDir, destDir) {
return fs.readdirAsync(srcDir).map(function(file) {
var destFile = path.join(destDir, file);
var srcFile = path.join(srcDir, file);
return fs.renameAsync(srcFile, destFile).then(function() {
return {file: srcFile, err: 0};
}).catch(function(err) {
console.log("error on " + srcFile);
return {file: srcFile, err: err}
});
}).then(function(files) {
var errors = files.filter(function(item) {
return item.err !== 0;
});
if (errors.length > 0) {
// reject with a list of error files and their corresponding errors
throw errors;
}
// for success, return list of all files moved
return files.filter(function(item) {
return item.file;
});
});
}
// sample usage:
moveFilesAll(path.join(".", "tempSource"), path.join(".", "tempDest")).then(function(files) {
// all done here
}).catch(function(errors) {
// list of errors here
});

Node.js check if path is file or directory

I can't seem to get any search results that explain how to do this.
All I want to do is be able to know if a given path is a file or a directory (folder).
The following should tell you. From the docs:
fs.lstatSync(path_string).isDirectory()
Objects returned from fs.stat() and fs.lstat() are of this type.
stats.isFile()
stats.isDirectory()
stats.isBlockDevice()
stats.isCharacterDevice()
stats.isSymbolicLink() // (only valid with fs.lstat())
stats.isFIFO()
stats.isSocket()
NOTE:
The above solution will throw an Error if; for ex, the file or directory doesn't exist.
If you want a true or false approach, try fs.existsSync(dirPath) && fs.lstatSync(dirPath).isDirectory(); as mentioned by Joseph in the comments below.
Update: Node.Js >= 10
We can use the new fs.promises API
const fs = require('fs').promises;
(async() => {
const stat = await fs.lstat('test.txt');
console.log(stat.isFile());
})().catch(console.error)
Any Node.Js version
Here's how you would detect if a path is a file or a directory asynchronously, which is the recommended approach in node.
using fs.lstat
const fs = require("fs");
let path = "/path/to/something";
fs.lstat(path, (err, stats) => {
if(err)
return console.log(err); //Handle error
console.log(`Is file: ${stats.isFile()}`);
console.log(`Is directory: ${stats.isDirectory()}`);
console.log(`Is symbolic link: ${stats.isSymbolicLink()}`);
console.log(`Is FIFO: ${stats.isFIFO()}`);
console.log(`Is socket: ${stats.isSocket()}`);
console.log(`Is character device: ${stats.isCharacterDevice()}`);
console.log(`Is block device: ${stats.isBlockDevice()}`);
});
Note when using the synchronous API:
When using the synchronous form any exceptions are immediately thrown.
You can use try/catch to handle exceptions or allow them to bubble up.
try{
fs.lstatSync("/some/path").isDirectory()
}catch(e){
// Handle error
if(e.code == 'ENOENT'){
//no such file or directory
//do something
}else {
//do something else
}
}
Seriously, question exists five years and no nice facade?
function isDir(path) {
try {
var stat = fs.lstatSync(path);
return stat.isDirectory();
} catch (e) {
// lstatSync throws an error if path doesn't exist
return false;
}
}
Depending on your needs, you can probably rely on node's path module.
You may not be able to hit the filesystem (e.g. the file hasn't been created yet) and tbh you probably want to avoid hitting the filesystem unless you really need the extra validation. If you can make the assumption that what you are checking for follows .<extname> format, just look at the name.
Obviously if you are looking for a file without an extname you will need to hit the filesystem to be sure. But keep it simple until you need more complicated.
const path = require('path');
function isFile(pathItem) {
return !!path.extname(pathItem);
}
If you need this when iterating over a directory (Because that's how I've found this question):
Since Node 10.10+, fs.readdir has a withFileTypes option which makes it return directory entry fs.Dirent instead of strings. Directory entries has a name property, and useful methods such as isDirectory or isFile, so you don't need to call fs.lstat explicitly.
import { promises as fs } from 'fs';
// ./my-dir has two subdirectories: dir-a, and dir-b
const dirEntries = await fs.readdir('./my-dir', { withFileTypes: true });
// let's filter all directories in ./my-dir
const onlyDirs = dirEntries.filter(de => de.isDirectory()).map(de => de.name);
// onlyDirs is now [ 'dir-a', 'dir-b' ]
Here's a function that I use. Nobody is making use of promisify and await/async feature in this post so I thought I would share.
const promisify = require('util').promisify;
const lstat = promisify(require('fs').lstat);
async function isDirectory (path) {
try {
return (await lstat(path)).isDirectory();
}
catch (e) {
return false;
}
}
Note : I don't use require('fs').promises; because it has been experimental for one year now, better not rely on it.
The answers above check if a filesystem contains a path that is a file or directory. But it doesn't identify if a given path alone is a file or directory.
The answer is to identify directory-based paths using "/." like --> "/c/dos/run/." <-- trailing period.
Like a path of a directory or file that has not been written yet. Or a path from a different computer. Or a path where both a file and directory of the same name exists.
// /tmp/
// |- dozen.path
// |- dozen.path/.
// |- eggs.txt
//
// "/tmp/dozen.path" !== "/tmp/dozen.path/"
//
// Very few fs allow this. But still. Don't trust the filesystem alone!
// Converts the non-standard "path-ends-in-slash" to the standard "path-is-identified-by current "." or previous ".." directory symbol.
function tryGetPath(pathItem) {
const isPosix = pathItem.includes("/");
if ((isPosix && pathItem.endsWith("/")) ||
(!isPosix && pathItem.endsWith("\\"))) {
pathItem = pathItem + ".";
}
return pathItem;
}
// If a path ends with a current directory identifier, it is a path! /c/dos/run/. and c:\dos\run\.
function isDirectory(pathItem) {
const isPosix = pathItem.includes("/");
if (pathItem === "." || pathItem ==- "..") {
pathItem = (isPosix ? "./" : ".\\") + pathItem;
}
return (isPosix ? pathItem.endsWith("/.") || pathItem.endsWith("/..") : pathItem.endsWith("\\.") || pathItem.endsWith("\\.."));
}
// If a path is not a directory, and it isn't empty, it must be a file
function isFile(pathItem) {
if (pathItem === "") {
return false;
}
return !isDirectory(pathItem);
}
Node version: v11.10.0 - Feb 2019
Last thought: Why even hit the filesystem?
I could check if a directory or file exists using this:
// This returns if the file is not a directory.
if(fs.lstatSync(dir).isDirectory() == false) return;
// This returns if the folder is not a file.
if(fs.lstatSync(dir).isFile() == false) return;
Function that returns type
I like coffee
type: (uri)-> (fina) ->
fs.lstat uri, (erro,stats) ->
console.log {erro} if erro
fina(
stats.isDirectory() and "directory" or
stats.isFile() and "document" or
stats.isSymbolicLink() and "link" or
stats.isSocket() and "socket" or
stats.isBlockDevice() and "block" or
stats.isCharacterDevice() and "character" or
stats.isFIFO() and "fifo"
)
usage:
dozo.type("<path>") (type) ->
console.log "type is #{type}"

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