CODEWITHSUNDEEP
node.jsexpressfilesystemsinternal-server-errorreaddir
cloudrain21
cloudrain21

Reputation: 659

Node.js filesystem work causes 500 server error

I'm testing some code by using node express framework and ajax. I'm facing a problem that I get a 500 server error in the front-end side. Server-size nodejs code is like below(Very simple). This is the code for express router. Once I add some code about filesystem work like below, I get an 500 error. But, if I remove the line about readdirSync function call, it works well. I don't understand what in the world may cause this kind of problem. I know the synchronous function is not so good for here, but it's just some simple test.

router.post('/pictureListFromFile', function(req, res, next) {
    var dirPath = "../public/img/laos1";
    var fileList = [];

    // fileList = fs.readdirSync(dirPath);   // --> This code cause the problem.
    console.log(fileList);

    // response here for ajax
});

Upvotes: 0

Views: 1324

Answers (2)

Angels
Angels

Reputation: 230

var fs = require('fs'); //if there is none

var fileList = [];
fileList.push(); //use push if you want to add to the array

But what causes the error in:

fs.readdirSync(dirPath);

is that dirPath is invalid. You have to use __dirname + path you need instead, or specify the correct path (C:/Program Files/...).

Upvotes: 1

Boris Charpentier
Boris Charpentier

Reputation: 3543

With readdirSync, as in most synchronous call in node, if there is an error, it will throw an error, crashing your server.

Never use synchronous call with node, the error management is based on try/catch and it do not scale well (it's actually freezing the entire node process).

Use the callback style : 

fs.readdir(dirPath, function (err, files){
   // rest of the code including res.send
});

Upvotes: 1

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