Node.js fs.stat not working as expected when used on module - node.js

i'm having a weird issue with fs.stat to check if a file is valid or not,
when i pass an absolute path with a variable (filePath in this case)
it appends the path of the project to the path i sent!
FileCompresser.CompressFile = (filePath,callback) =>{
console.log(filePath);
fs.stat(filePath,(err,stat)=>{
if(err){
callback(err,null);
return;
}
var readStream = fs.createReadStream(filePath).pipe(zlib.createGzip());
callback(null,readStream);
});
}
AssertionError: expected Error {
code: 'ENOENT',
errno: -4058,
path: 'C:\\carpetica\\NodeCompress\\‪‪C:\\carpetica\\delete.reg',
syscall: 'stat',
message: 'ENOENT: no such file or directory, stat \'C:\\carpetica\\NodeCompress\\‪‪C:\\carpetica\\delete.reg\''
} to not exist
yet if i do the following it works correctly :
fs.stat("C:/carpetica/delete.reg",(err,stat)=>{
if(err){
callback(err,null);
return;
}
var readStream = fs.createReadStream(filePath).pipe(zlib.createGzip());
callback(null,readStream);
});
but of course that is not good for testing... i send exactly the same value i hard coded there... yet i get that weird behavior.. this behavior doesn't happen when i run directly from the REPL without modules.
UPDATE:
found the culprit ( i think!), i tested with 2 paths, and the only thing different were the
' and the "" surrounding the strings
it("should return a compressed file",(done)=>{
var path2 = '‪F:/ISOS/linuxmint-17.1-mate-64bit.iso';//this doesnt work!
var path1 = "C:/carpetica/delete.reg";//but this does!
FileCompresser.CompressFile(path2, (err,CompressedfileStream) =>{
should.not.exists(err);
should(CompressedfileStream).be.ok();
done();
});
} );
as soon as i wrapped path2 on double quotes it worked as intended :)

Related

How to read the contents of a file onto the console using Nodejs

I am going back to learning js after many years off and all i want to do is read the contents of a file onto the console using Nodejs. I found the sample code. Nice and simple. I have spent over an hour trying to figure out why it will not find the file. This is sample right off the documentation and i made it exactly like the example to debug it. The absolute only difference is the name joe is replaced with my user folder.
const fs = require('fs')
fs.readFile('/Users/gendi/test.txt', 'utf8' , (err, data) => {
if (err) {
console.error(err)
return
}
console.log(data)
})
It runs fine except it will not find test.text. no matter what. I receive the following error and no matter how i format the file path. Nothing.
C:\Users\gendi>node readfile.js
[Error: ENOENT: no such file or directory, open 'C:\Users\gendi\test.txt'] {
errno: -4058,
code: 'ENOENT',
syscall: 'open',
path: 'C:\\Users\\gendi\\pcsSnipe\\test.txt'
}
You can also only pass in the file path as 'test.txt' and the exact same results come up. on the first part of the error msg the path looks formatted correctly but on the last line of the error msg it is not? Its been years.. so i know i am missing something really simple. I assure that file is there!! Thank you in advance and forgive my ineptness.
The fs module requires an exact path to the file you'd like to read. A simple fix to this would be to add __dirname which will return the directory path along with the path of your file.
// Define modules
const fs = require('fs');
const path = require('path');
// Read the file
fs.readFile(path.join(__dirname, '/Users/gendi/test.txt'), 'utf8' , (err, data) => {
if (err) // If FS returned an error
return console.error(err); // Log the error and return
console.log(data); // If the reading was successful, log the data
});
It works if you remove the file extention, '.txt' . Idk why it make a differnce. maybe the "." is throwing it off but it doesn't matter in this respect. Thank you

Error writing a file using 'fs' in Node

I'm trying to write to a file using the following function:
function writeFile (data, callback) {
var fs = require('fs');
var now = new Date();
fs.writeFile(now.toISOString() + ".json", data, function(err) {
if (err) {
return console.log(err);
} else {
console.log(true);
}
});
}
but im getting an error like this:
{ Error: ENOENT: no such file or directory, open 'C:\Users\Ruslan\WebstormProjects\communication-system\client\6\28\2017_19:47:55.json'
errno: -4058,
code: 'ENOENT',
syscall: 'open',
path: 'C:\\Users\\Me\\WebstormProjects\\blah-blah\\client\\6\\28\\2017_19:47:55.json' }
I'm trying to create a file every time I run the program, but that doesn't seem to work very well because it says file does not exist. Is there anything im doing wrong? BTW, im running this on windows
EDIT: It was indeed wrong file name that was bugging the saving process
When you call fs.writeFile() you have to pass it a filename/path:
Where the parent directory in the path already exists.
Where the path/filename contains only characters that are legal for your OS.
It appears you are likely failing both of these unless you've pre-created the directory: C:\Users\Ruslan\WebstormProjects\communication-system\client\6\28. And, if this is running on Windows, then you also can't use : in a filename.
Assume you actually want the path to be C:\Users\Ruslan\WebstormProjects\communication-system\client and what the filename to be based on your now.toISOString(), the usual work-around is to replace path separators and other invalid filename characters with safe characters to you convert your now.toISOString() to something that is always a safe filename. In this case, you could do this:
// replace forward and back slashes and colons with an underscore
// to make sure this is a legal OS filename
let filename = now.toISOString().replace(/[\/\\:]/g, "_") + ".json";
fs.writeFile(filename, ....)

writeFile no such file or directory

I have a file(data.file an image), I would like to save this image. Now an image with the same name could exist before it. I would like to overwrite if so or create it if it does not exist since before. I read that the flag "w" should do this.
Code:
fs.writeFile('/avatar/myFile.png', data.file, {
flag: "w"
}, function(err) {
if (err) {
return console.log(err);
}
console.log("The file was saved!");
});
Error:
[Error: ENOENT: no such file or directory, open '/avatar/myFile.png']
errno: -2,
code: 'ENOENT',
syscall: 'open',
path: '/avatar/myFile.png'
This is probably because you are trying to write to root of file system instead of your app directory '/avatar/myFile.png' -> __dirname + '/avatar/myFile.png' should do the trick, also check if folder exists. node.js won't create parent folder for you.
Many of us are getting this error because parent path does not exist. E.g. you have /tmp directory available but there is no folder "foo" and you are writing to /tmp/foo/bar.txt.
To solve this, you can use mkdirp - adapted from How to write file if parent folder doesn't exist?
Option A) Using Callbacks
const mkdirp = require('mkdirp');
const fs = require('fs');
const getDirName = require('path').dirname;
function writeFile(path, contents, cb) {
mkdirp(getDirName(path), function (err) {
if (err) return cb(err);
fs.writeFile(path, contents, cb);
});
}
Option B) Using Async/Await
Or if you have an environment where you can use async/await:
const mkdirp = require('mkdirp');
const fs = require('fs');
const writeFile = async (path, content) => {
await mkdirp(path);
fs.writeFileSync(path, content);
}
I solved a similar problem where I was trying to create a file with a name that contained characters that are not allowed. Watch out for that as well because it gives the same error message.
I ran into this error when creating some nested folders asynchronously right before creating the files. The destination folders wouldn't always be created before promises to write the files started. I solved this by using mkdirSync instead of 'mkdir' in order to create the folders synchronously.
try {
fs.mkdirSync(DestinationFolder, { recursive: true } );
} catch (e) {
console.log('Cannot create folder ', e);
}
fs.writeFile(path.join(DestinationFolder, fileName), 'File Content Here', (err) => {
if (err) throw err;
});
Actually, the error message for the file names that are not allowed in Linux/ Unix system comes up with the same error which is extremely confusing. Please check the file name if it has any of the reserved characters. These are the reserved /, >, <, |, :, & characters for Linux / Unix system. For a good read follow this link.
It tells you that the avatar folder does not exist.
Before writing a file into this folder, you need to check that a directory called "avatar" exists and if it doesn't, create it:
if (!fs.existsSync('/avatar')) {
fs.mkdirSync('/avatar', { recursive: true});
}
you can use './' as a prefix for your path.
in your example, you will write:
fs.writeFile('./avatar/myFile.png', data.file, (err) => {
if (err) {
return console.log(err);
}
console.log("The file was saved!");
});
I had this error because I tried to run:
fs.writeFile(file)
fs.unlink(file)
...lots of code... probably not async issue...
fs.writeFile(file)
in the same script. The exception occurred on the second writeFile call. Removing the first two calls solved the problem.
In my case, I use async fs.mkdir() and then, without waiting for this task to complete, I tried to create a file fs.writeFile()...
As SergeS mentioned, using / attempts to write in your system root folder, but instead of using __dirname, which points to the path of the file where writeFile is invoked, you can use process.cwd() to point to the project's directory. Example:
writeFile(`${process.cwd()}/pictures/myFile.png`, data, (err) => {...});
If you want to avoid string concatenations/interpolations, you may also use path.join(process.cwd(), 'pictures', 'myFile.png') (more details, including directory creation, in this digitalocean article).

Remove file Synchronously can't find file

I have this function that make a directory have same files as the other one, so one directory is the source and the other is the one that should look like it so it removes files found in the second one that doesn't exist in the src. Anyway the thing is in the function below if I replaced fs.rmdirSyncwith fs.rmdir it works but if I don't it returns the error shown below.
function (srcDir, similarDir){
srcDir = path.resolve(process.cwd(),srcDir);
similarDir = path.resolve(process.cwd(),similarDir);
var info = {deletedFiles : 0, deletedDir : 0};
dive(similarDir,function(err, file){
if(err){
console.log(err.toString())
}
else
{
var baseFile = path.basename(file,'.css');
var srcFileDir = path.dirname(file).replace(similarDir,srcDir)
var srcFilePath = path.resolve(srcFileDir , baseFile);
if(!fs.existsSync(srcFilePath)){
console.log("before");
try {
fs.rmdirSync(file)
}
catch(error){
console.log(error)
}
console.log("after");
info.deletedFiles++;
}
}
})
This is the error that occurs when I use fs.rmdirsync although the file does exist and If i changed it to fs.rmdir it works ( on windows os )
{ [Error: ENOENT, no such file or directory 'D:\angularjs\build\css\components\test\test\test.css']
errno: 34,
code: 'ENOENT',
path: 'D:\\angularjs\\build\\css\\components\\test\\test\\test.css',
syscall: 'rmdir' }
Try upgrading to fs-extra, fs.removeSync() works without issue.

node.js fs rename ENOENT

I am trying to write a handler for file uploads in node.js using express framework. Following is the raw skeleton of it.
exports.handleUpload = function(req,res){
var temp_path = req.files.doc.path,
target_path = './uploads/' + req.files.doc.name ;
fs.rename(temp_path, target_path, function(err){
if(err){
console.log(err);
}
fs.unlink(temp_path, function(){
if(err){
console.log(err)
}
})
//Do stuff
})
}
However I get an error in the execution of renmae function occassionally(not always), especially with uploads of large files.
This is what the console caches from the error code
{ [Error: ENOENT, rename '/tmp/16368-19661hu.pptx'] errno: 34, code: 'ENOENT', path: '/tmp/16368-19661hu.pptx' }
From : https://github.com/joyent/node/blob/master/deps/uv/include/uv.h
XX(ENOENT, "no such file or directory")
The uploads/ directory does exist and permissions isn't an issue. Had it been so, it would have been failing each time, but it does not.
You're using the /tmp directory. The OS might be deleting the files since it can do so for the /tmp directory, hence the "randomness" of the issue. Use fs.exists before doing your other operations.

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