reading a file using node.js

Question

trying to read a file using node.js

    var fs = require('fs');
    fs.readFile("details.txt",'utf8',function(err,data)
    {
        if(err)
        {
            return console.log(err);
        }
        response.write(data);
    });

there is a file alredy with some text in the same directory.

Error im getting is :

response.write(data); ^ ReferenceError: data is not defined

I can't think of any reason why err would be false but data undefined. — Quentin
– Quentin, Commented Apr 17, 2016 at 14:10
./ refers to the working directory. Juat trying to ensure it is looking in the right place. — mcgraphix
– mcgraphix, Commented Apr 17, 2016 at 14:15

Michael Seltene · Accepted Answer · 2016-04-17 15:13:18Z

1

File order

Above img shows my File order. Note: I'm using IntelliJ IDEA. You will have to find the file "details.txt" in your system.

//Instead of using hard coded path, use: the following code to get the path in Node.js
//var path = require('path');
//console.log(path.join(__dirname, '../details.txt'));

//require file system
var fs = require('fs');

//read file
fs.readFile("details.txt",'utf8',function(err,data){

  //if error, log error and return
  if(err) { return console.error('Error: ' + err); }


  //check if there is data in the file
  if(data) {

     //EDITED to include line break
    //write response
    //response.write('<div style="color:green">' + data + '</div>');

    //write response with <br>
    response.write('<div style="color:green">' + data.split('\n').join('<br>') + '</div>');

    //end the response
    response.end();


  //if no data on the file, do the following
  }else{
    //error variable
    var error = "Error: file is empty: " + data.length + " bytes.";

    //log error
    // console.error(error);

    //write response
    response.write('<div style="color:red">' + error + '</div>');

    //end response
    response.end();
  }
});

edited Apr 17, 2016 at 15:13

answered Apr 17, 2016 at 14:41

Michael Seltene

6012 gold badges8 silver badges18 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

Asanka Over a year ago

Yes!!! It's worked. Thanks so much!!!! Any tips of retrieving the output line by line ? at the moment it is displaying all the details in one line.

Nidhin David Over a year ago

@CJM You can use readLine function instead. stackoverflow.com/a/32599033/3359432

Michael Seltene Over a year ago

Ok, I have edited the code for write data to. data.split('\n').join('<br>')

Muhammad F. Musad · Accepted Answer · 2016-04-17 14:21:14Z

0

   var fs = require('fs');
    fs.readFile("details.txt",'utf8',function(err,data)
    {
        if(err)
        {
            return console.log(err);
        }
        console.log(data);
    });

the error is

response.write(data)

answered Apr 17, 2016 at 14:21

Muhammad F. Musad

8778 silver badges17 bronze badges

Comments

Gary Stafford · Accepted Answer · 2016-04-17 14:21:24Z

0

Try using the full path to 'details.txt' (i.e. '/etc/hosts'). And, send it to console.log just to confirm it works.

edited Apr 17, 2016 at 14:21

answered Apr 17, 2016 at 14:11

Gary Stafford

3213 silver badges11 bronze badges

2 Comments

Asanka Over a year ago

it is in the home directory where all the other files are server.js, router.js

Asanka Over a year ago

I can write into the file but only when im reading it gives me that error.

Collectives™ on Stack Overflow

reading a file using node.js

3 Answers 3

3 Comments

Comments

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

3 Comments

Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related