I am trying to unzip a text file using Zlib library in node.js, but i get unexpected end of file error, when piping the files’s Readstream content towards a Gunzip object, here is my snippet:

const fs = require('fs');
const zlib = require("zlib");

var readable = fs.createReadStream(__dirname + '/greet.txt');
var readableGz = fs.createReadStream(__dirname + '/greet.txt.gz');
var writableGz = fs.createWriteStream(__dirname + '/greet.txt.gz');
var gZip = zlib.createGzip();
var gUnZip = zlib.createGunzip();

readable.pipe(gZip).pipe(writableGz);   // press file
readableGz.pipe(gUnZip).on("error", function(e){    // unpress file
    console.log("error, " + e);
});

The greet.txt has some random text in it, and all the files used are already created in the directory, however an error event is triggered when the last line reaches

I am trying to unzip a text file using Zlib library in node.js, but i get unexpected end of file error, when piping the files’s Readstream content towards a Gunzip object, here is my snippet:

const fs = require('fs');
const zlib = require("zlib");

var readable = fs.createReadStream(__dirname + '/greet.txt');
var readableGz = fs.createReadStream(__dirname + '/greet.txt.gz');
var writableGz = fs.createWriteStream(__dirname + '/greet.txt.gz');
var gZip = zlib.createGzip();
var gUnZip = zlib.createGunzip();

readable.pipe(gZip).pipe(writableGz);   // press file
readableGz.pipe(gUnZip).on("error", function(e){    // unpress file
    console.log("error, " + e);
});

The greet.txt has some random text in it, and all the files used are already created in the directory, however an error event is triggered when the last line reaches

• javascript
• node.js
• zlib
• fs

Share Improve this question Follow edited Jan 8, 2017 at 4:16 v-andrew 24.3k66 gold badges3838 silver badges4242 bronze badges asked Jan 8, 2017 at 1:05 Pablo MarinoPablo Marino 49111 gold badge55 silver badges1212 bronze badges 2

• You are writing and reading in parallel. Wait until it's finished writing before reading. – cartant Commented Jan 8, 2017 at 1:13
• if i first press the file, and then ment that part, and just run the part when i try to unpress it, the same error is still happening – Pablo Marino Commented Jan 8, 2017 at 1:23

Add a ment  | 

1 Answer 1

Sorted by: Reset to default 6

All node operations are asynchronous, so you have to listen for finish event.

readable.pipe(gZip).pipe(writableGz)
   .on('finish', function () {  // finished
        console.log('Done. Now you can start reading.'); 
});

Here is a working code:

const fs = require('fs');
const zlib = require("zlib");

var readable = fs.createReadStream('./greet.txt');
var writableGz = fs.createWriteStream('./greet.txt.gz');
var gZip = zlib.createGzip();
var gUnZip = zlib.createGunzip();

readable
    .pipe(gZip)
    .pipe(writableGz)
    .on('finish', function () {  // finished
        console.log('Done. Now you can start reading.');
        var readableGz = fs.createReadStream('./greet.txt.gz');
        readableGz
            .pipe(gUnZip)  // extract file
            .on("error", function (e) {
                console.log("error, " + e); 
            });
});