After executing this code:
const filename = "../../.dburl"
const url = fs.readFileSync(filename, 'utf-8')
I recieve the following error:
Error: ENOENT: no such file or directory, open '../../.dburl'
What I know so far:
1) The filepath is correct.
2) My application has permission to read the file.
3) .dburl is not read even when stored in the same directory as the application.
Any help is much appreciated ... Thanks!
You can use the module-level variable __dirname to get the directory that contains the current script. Then you can use path.resolve() to use relative paths.
console.log('Path of file in parent dir:', require('path').resolve(__dirname, '../app.js'));
READING FILE ON SAME LEVEL
//the server object listens on port 8080
const PORT = 8080;
var http = require("http");
var fs = require("fs");
var path = require("path");
//create a server object:
http
.createServer((req, res) => {
console.log("READING FILE: ", path.resolve(__dirname, "input.txt"));
fs.readFile(path.resolve(__dirname, "input.txt"), (err, data) => {
//error handling
if (err) return console.error(err);
//return file content
console.log("FILE CONTENT: " + data.toString());
res.write(data.toString());
res.end();
console.log("READ COMPLETED");
});
})
.listen(PORT);
READING FILE ON OTHER LEVEL:
//the server object listens on port 8080
const PORT = 8080;
var http = require("http");
var fs = require("fs");
var path = require("path");
//create a server object:
http
.createServer((req, res) => {
console.log("READING FILE: ", path.resolve(__dirname, "./mock/input.txt"));
fs.readFile(path.resolve(__dirname, "./mock/input.txt"), (err, data) => {
//error handling
if (err) return console.error(err);
//return file content
console.log("FILE CONTENT: " + data.toString());
res.write(data.toString());
res.end();
console.log("READ COMPLETED");
});
})
.listen(PORT);
I'm guessing you're confusing the current working directory of your script for the location of your script. It's hard to say without knowing the structure of your project and where you're calling the script from.
Assuming your shell's working directory is /, .dburl is at /.dburl and your script is located at /foo/bar/script.js. If you run node foo/bar/script, you could read .dburl with readFileSync('./dburl'). However if you run cd foo/bar; node ./script, you would need to read .dburl with readFileSync('../../.dburl').
This is because the working directory of your script is equal to the working directory of the shell you launched it in.
I have a file in D: Drive of my local system. I need to download the file into the E: Drive. How to do this using node.js and http request? I am a beginner in node.js. Please give me valuable suggestions.
Note: The file may be in any type.
Here is an example:
// upload.js
var fs = require('fs')
var newPath = "E:\\newPath";
var oldPath = "D:\\oldPath";
exports.uploadFile = function (req, res) {
fs.readFile(oldPath, function(err, data) {
fs.writeFile(newPath, data, function(err) {
fs.unlink(oldPath, function(){
if(err) throw err;
res.send("File uploaded to: " + newPath);
});
});
});
};
// app.js
var express = require('express'), // fetch express js library
upload = require('./upload'); // fetch upload.js you have just written
var app = express();
app.get('/upload', upload.uploadFile);
app.listen(3000);
Basically there are two parts, one doing the copying from one drive to another, and the other one is for triggering. Once you run you app.js and make a GET request to localhost:3000/upload it will copy the file from newPath to the oldPath. For further information have a look to expressjs and fs.
Assuming it's a text file, you would have to write two node.js server.
The first would answer (all/specific, your choice) http get with the content of the file, the other would make a get and download the file.
server.js: Will work only for text file
var http = require('http'),
fs = require('fs'),
server = http.createServer(function (req, res){
res.writeHead(200, {'content-type': 'text/text'});
fs.readFile('E:/path/to/file.txt', function (data) {
res.write('' + data);
res.end();
});
}).listen(8080);
client.js
var http = require('http'),
fs = require('fs'),
file = fs.createWriteStream('D:/path/to/new.txt', {flags: 'w'});
http.get('http://localhost:8080', function (res) {
res.pipe(file, {end: 'false'});
res.on('end', function() {
file.end();
});
});
EDIT:
The only advantage versus anvarik's solution is that I don t use express...
In most examples you find on the web, an index.html file is served like the following:
function serveIndexPage(response) {
fs.readFile('__dirname + /public/index.html', function (err, data) {
response.end(data);
});
};
This seems like a bad idea, as the whole file is read into memory and then send to the client. Is there some better way to do this? I know that libaries like Connect and Express provide such a functionality, but for my project, I'd like to use plain node.js.
EDIT
Also, you sometimes see readFileSync used, which is even worse IMHO.
Pipe your data through, so a simple static HTTP server looks like:
var Http = require('http'),
Url = require('url'),
Path = require('path'),
Fs = require('fs');
Http.createServer(function(req, res) {
var path = Url.parse(req.url).pathname;
var file = Path.join(process.cwd(), path);
path.exists(filename, function(exists) {
if(!exists) {
res.writeHead(404);
res.end();
}
res.writeHead(200, /* mime type */);
var fileStream = Fs.createReadStream(filename);
fileStream.pipe(res);
});
}).listen(process.env.PORT || 1999);
The pipe'ing is shorthand for something like
var s = Fs.createReadStream(filename);
s.on('data', function (data) {
res.write(data);
});
s.on('end', function() {
res.end();
});
In theory you could read the file line by line response.write()'ing every line to the client.
So I have my app at http://localhost:8080/
How can I have http://localhost:8080/subpage ? Because it seems like any page that hits :8080 pulls the server.js
thanks!
** edit - here's what worked for me (thanks to stewe's answer) **
var app = require('http').createServer(createServer);
var fs = require('fs');
var url = require('url');
function createServer(req, res) {
var path = url.parse(req.url).pathname;
var fsCallback = function(error, data) {
if(error) throw error;
res.writeHead(200);
res.write(data);
res.end();
}
switch(path) {
case '/subpage':
doc = fs.readFile(__dirname + '/subpage.html', fsCallback);
break;
default:
doc = fs.readFile(__dirname + '/index.html', fsCallback);
break;
}
}
app.listen(8080);
Here is a start:
var http=require('http');
var url=require('url');
var server=http.createServer(function(req,res){
var pathname=url.parse(req.url).pathname;
switch(pathname){
case '/subpage':
res.end('subpage');
break;
default:
res.end('default');
break;
}
}).listen(8080);
I hit the same problem as you did, and I think what we were both looking for is basically a routing engine for node.js. Basically, okay fine I get the hello-world example for nodejs, but how do I build something that responds to different requests?
For future users who land on this page via google, you must look at Express.js and this excellent guide and intro into express, Understanding Express.js. These two will solve the problem
I have a logo that is residing at the public/images/logo.gif. Here is my nodejs code.
http.createServer(function(req, res){
res.writeHead(200, {'Content-Type': 'text/plain' });
res.end('Hello World \n');
}).listen(8080, '127.0.0.1');
It works but when I request for localhost:8080/logo.gif then I obviously don't get the logo.
What changes I need to do to serve an image.
2016 Update
Examples with Express and without Express that actually work
This question is over 5 years old but every answer has some problems.
TL;DR
Scroll down for examples to serve an image with:
express.static
express
connect
http
net
All of the examples are also on GitHub: https://github.com/rsp/node-static-http-servers
Test results are available on Travis: https://travis-ci.org/rsp/node-static-http-servers
Introduction
After over 5 years since this question was asked there is only one correct answer by generalhenry but even though that answer has no problems with the code, it seems to have some problems with reception. It was commented that it "doesn't explain much other than how to rely on someone else to get the job done" and the fact how many people have voted this comment up clearly shows that a lot of things need clarification.
First of all, a good answer to "How to serve images using Node.js" is not implementing a static file server from scratch and doing it badly. A good answer is using a module like Express that does the job correctly.
Answering comments that say that using Express "doesn't explain much other than how to rely on someone else to get the job done" it should be noted, that using the http module already relies on someone else to get the job done. If someone doesn't want to rely on anyone to get the job done then at least raw TCP sockets should be used instead - which I do in one of my examples below.
A more serious problem is that all of the answers here that use the http module are broken. They introduce race conditions, insecure path resolution that will lead to path traversal vulnerability, blocking I/O that will completely fail to serve any concurrent requests at all and other subtle problems - they are completely broken as examples of what the question asks about, and yet they already use the abstraction that is provided by the http module instead of using TCP sockets so they don't even do everything from scratch as they claim.
If the question was "How to implement static file server from scratch, as a learning exercise" then by all means answers how to do that should be posted - but even then we should expect them to at least be correct. Also, it is not unreasonable to assume that someone who wants to serve an image might want to serve more images in the future so one could argue that writing a specific custom static file server that can serve only one single file with hard-coded path is somewhat shortsighted. It seems hard to imagine that anyone who searches for an answer on how to serve an image would be content with a solution that serves just a single image instead of a general solution to serve any image.
In short, the question is how to serve an image and an answer to that is to use an appropriate module to do that in a secure, performant and reliable way that is readable, maintainable and future-proof while using the best practice of professional Node development. But I agree that a great addition to such an answer would be showing a way to implement the same functionality manually but sadly every attempt to do that has failed so far. And that is why I wrote some new examples.
After this short introduction, here are my five examples doing the job on 5 different levels of abstraction.
Minimum functionality
Every example serves files from the public directory and supports the minimum functionality of:
MIME types for most common files
serves HTML, JS, CSS, plain text and images
serves index.html as a default directory index
responds with error codes for missing files
no path traversal vulnerabilities
no race conditions while reading files
I tested every version on Node versions 4, 5, 6 and 7.
express.static
This version uses the express.static built-in middleware of the express module.
This example has the most functionality and the least amount of code.
var path = require('path');
var express = require('express');
var app = express();
var dir = path.join(__dirname, 'public');
app.use(express.static(dir));
app.listen(3000, function () {
console.log('Listening on http://localhost:3000/');
});
express
This version uses the express module but without the express.static middleware. Serving static files is implemented as a single route handler using streams.
This example has simple path traversal countermeasures and supports a limited set of most common MIME types.
var path = require('path');
var express = require('express');
var app = express();
var fs = require('fs');
var dir = path.join(__dirname, 'public');
var mime = {
html: 'text/html',
txt: 'text/plain',
css: 'text/css',
gif: 'image/gif',
jpg: 'image/jpeg',
png: 'image/png',
svg: 'image/svg+xml',
js: 'application/javascript'
};
app.get('*', function (req, res) {
var file = path.join(dir, req.path.replace(/\/$/, '/index.html'));
if (file.indexOf(dir + path.sep) !== 0) {
return res.status(403).end('Forbidden');
}
var type = mime[path.extname(file).slice(1)] || 'text/plain';
var s = fs.createReadStream(file);
s.on('open', function () {
res.set('Content-Type', type);
s.pipe(res);
});
s.on('error', function () {
res.set('Content-Type', 'text/plain');
res.status(404).end('Not found');
});
});
app.listen(3000, function () {
console.log('Listening on http://localhost:3000/');
});
connect
This version uses the connect module which is a one level of abstraction lower than express.
This example has similar functionality to the express version but using slightly lower-lever APIs.
var path = require('path');
var connect = require('connect');
var app = connect();
var fs = require('fs');
var dir = path.join(__dirname, 'public');
var mime = {
html: 'text/html',
txt: 'text/plain',
css: 'text/css',
gif: 'image/gif',
jpg: 'image/jpeg',
png: 'image/png',
svg: 'image/svg+xml',
js: 'application/javascript'
};
app.use(function (req, res) {
var reqpath = req.url.toString().split('?')[0];
if (req.method !== 'GET') {
res.statusCode = 501;
res.setHeader('Content-Type', 'text/plain');
return res.end('Method not implemented');
}
var file = path.join(dir, reqpath.replace(/\/$/, '/index.html'));
if (file.indexOf(dir + path.sep) !== 0) {
res.statusCode = 403;
res.setHeader('Content-Type', 'text/plain');
return res.end('Forbidden');
}
var type = mime[path.extname(file).slice(1)] || 'text/plain';
var s = fs.createReadStream(file);
s.on('open', function () {
res.setHeader('Content-Type', type);
s.pipe(res);
});
s.on('error', function () {
res.setHeader('Content-Type', 'text/plain');
res.statusCode = 404;
res.end('Not found');
});
});
app.listen(3000, function () {
console.log('Listening on http://localhost:3000/');
});
http
This version uses the http module which is the lowest-level API for HTTP in Node.
This example has similar functionality to the connect version but using even more lower-level APIs.
var path = require('path');
var http = require('http');
var fs = require('fs');
var dir = path.join(__dirname, 'public');
var mime = {
html: 'text/html',
txt: 'text/plain',
css: 'text/css',
gif: 'image/gif',
jpg: 'image/jpeg',
png: 'image/png',
svg: 'image/svg+xml',
js: 'application/javascript'
};
var server = http.createServer(function (req, res) {
var reqpath = req.url.toString().split('?')[0];
if (req.method !== 'GET') {
res.statusCode = 501;
res.setHeader('Content-Type', 'text/plain');
return res.end('Method not implemented');
}
var file = path.join(dir, reqpath.replace(/\/$/, '/index.html'));
if (file.indexOf(dir + path.sep) !== 0) {
res.statusCode = 403;
res.setHeader('Content-Type', 'text/plain');
return res.end('Forbidden');
}
var type = mime[path.extname(file).slice(1)] || 'text/plain';
var s = fs.createReadStream(file);
s.on('open', function () {
res.setHeader('Content-Type', type);
s.pipe(res);
});
s.on('error', function () {
res.setHeader('Content-Type', 'text/plain');
res.statusCode = 404;
res.end('Not found');
});
});
server.listen(3000, function () {
console.log('Listening on http://localhost:3000/');
});
net
This version uses the net module which is the lowest-level API for TCP sockets in Node.
This example has some of the functionality of the http version but the minimal and incomplete HTTP protocol has been implemented from scratch. Since it doesn't support chunked encoding it loads the files into memory before serving them to know the size before sending a response because statting the files and then loading would introduce a race condition.
var path = require('path');
var net = require('net');
var fs = require('fs');
var dir = path.join(__dirname, 'public');
var mime = {
html: 'text/html',
txt: 'text/plain',
css: 'text/css',
gif: 'image/gif',
jpg: 'image/jpeg',
png: 'image/png',
svg: 'image/svg+xml',
js: 'application/javascript'
};
var server = net.createServer(function (con) {
var input = '';
con.on('data', function (data) {
input += data;
if (input.match(/\n\r?\n\r?/)) {
var line = input.split(/\n/)[0].split(' ');
var method = line[0], url = line[1], pro = line[2];
var reqpath = url.toString().split('?')[0];
if (method !== 'GET') {
var body = 'Method not implemented';
con.write('HTTP/1.1 501 Not Implemented\n');
con.write('Content-Type: text/plain\n');
con.write('Content-Length: '+body.length+'\n\n');
con.write(body);
con.destroy();
return;
}
var file = path.join(dir, reqpath.replace(/\/$/, '/index.html'));
if (file.indexOf(dir + path.sep) !== 0) {
var body = 'Forbidden';
con.write('HTTP/1.1 403 Forbidden\n');
con.write('Content-Type: text/plain\n');
con.write('Content-Length: '+body.length+'\n\n');
con.write(body);
con.destroy();
return;
}
var type = mime[path.extname(file).slice(1)] || 'text/plain';
var s = fs.readFile(file, function (err, data) {
if (err) {
var body = 'Not Found';
con.write('HTTP/1.1 404 Not Found\n');
con.write('Content-Type: text/plain\n');
con.write('Content-Length: '+body.length+'\n\n');
con.write(body);
con.destroy();
} else {
con.write('HTTP/1.1 200 OK\n');
con.write('Content-Type: '+type+'\n');
con.write('Content-Length: '+data.byteLength+'\n\n');
con.write(data);
con.destroy();
}
});
}
});
});
server.listen(3000, function () {
console.log('Listening on http://localhost:3000/');
});
Download examples
I posted all of the examples on GitHub with more explanation.
Examples with express.static, express, connect, http and net:
https://github.com/rsp/node-static-http-servers
Other project using only express.static:
https://github.com/rsp/node-express-static-example
Tests
Test results are available on Travis:
https://travis-ci.org/rsp/node-static-http-servers
Everything is tested on Node versions 4, 5, 6, and 7.
See also
Other related answers:
Failed to load resource from same directory when redirecting Javascript
onload js call not working with node
Sending whole folder content to client with express
Loading partials fails on the server JS
Node JS not serving the static image
I agree with the other posters that eventually, you should use a framework, such as Express.. but first you should also understand how to do something fundamental like this without a library, to really understand what the library abstracts away for you.. The steps are
Parse the incoming HTTP request, to see which path the user is asking for
Add a pathway in conditional statement for the server to respond to
If the image is requested, read the image file from the disk.
Serve the image content-type in a header
Serve the image contents in the body
The code would look something like this (not tested)
fs = require('fs');
http = require('http');
url = require('url');
http.createServer(function(req, res){
var request = url.parse(req.url, true);
var action = request.pathname;
if (action == '/logo.gif') {
var img = fs.readFileSync('./logo.gif');
res.writeHead(200, {'Content-Type': 'image/gif' });
res.end(img, 'binary');
} else {
res.writeHead(200, {'Content-Type': 'text/plain' });
res.end('Hello World \n');
}
}).listen(8080, '127.0.0.1');
You should use the express framework.
npm install express
and then
var express = require('express');
var app = express();
app.use(express.static(__dirname + '/public'));
app.listen(8080);
and then the URL localhost:8080/images/logo.gif should work.
var http = require('http');
var fs = require('fs');
http.createServer(function(req, res) {
res.writeHead(200,{'content-type':'image/jpg'});
fs.createReadStream('./image/demo.jpg').pipe(res);
}).listen(3000);
console.log('server running at 3000');
It is too late but helps someone, I'm using node version v7.9.0 and express version 4.15.0
if your directory structure is something like this:
your-project
uploads
package.json
server.js
server.js code:
var express = require('express');
var app = express();
app.use(express.static(__dirname + '/uploads'));// you can access image
//using this url: http://localhost:7000/abc.jpg
//make sure `abc.jpg` is present in `uploads` dir.
//Or you can change the directory for hiding real directory name:
`app.use('/images', express.static(__dirname+'/uploads/'));// you can access image using this url: http://localhost:7000/images/abc.jpg
app.listen(7000);
Vanilla node version as requested:
var http = require('http');
var url = require('url');
var path = require('path');
var fs = require('fs');
http.createServer(function(req, res) {
// parse url
var request = url.parse(req.url, true);
var action = request.pathname;
// disallow non get requests
if (req.method !== 'GET') {
res.writeHead(405, {'Content-Type': 'text/plain' });
res.end('405 Method Not Allowed');
return;
}
// routes
if (action === '/') {
res.writeHead(200, {'Content-Type': 'text/plain' });
res.end('Hello World \n');
return;
}
// static (note not safe, use a module for anything serious)
var filePath = path.join(__dirname, action).split('%20').join(' ');
fs.exists(filePath, function (exists) {
if (!exists) {
// 404 missing files
res.writeHead(404, {'Content-Type': 'text/plain' });
res.end('404 Not Found');
return;
}
// set the content type
var ext = path.extname(action);
var contentType = 'text/plain';
if (ext === '.gif') {
contentType = 'image/gif'
}
res.writeHead(200, {'Content-Type': contentType });
// stream the file
fs.createReadStream(filePath, 'utf-8').pipe(res);
});
}).listen(8080, '127.0.0.1');
I like using Restify for REST services. In my case, I had created a REST service to serve up images and then if an image source returned 404/403, I wanted to return an alternative image. Here's what I came up with combining some of the stuff here:
function processRequest(req, res, next, url) {
var httpOptions = {
hostname: host,
path: url,
port: port,
method: 'GET'
};
var reqGet = http.request(httpOptions, function (response) {
var statusCode = response.statusCode;
// Many images come back as 404/403 so check explicitly
if (statusCode === 404 || statusCode === 403) {
// Send default image if error
var file = 'img/user.png';
fs.stat(file, function (err, stat) {
var img = fs.readFileSync(file);
res.contentType = 'image/png';
res.contentLength = stat.size;
res.end(img, 'binary');
});
} else {
var idx = 0;
var len = parseInt(response.header("Content-Length"));
var body = new Buffer(len);
response.setEncoding('binary');
response.on('data', function (chunk) {
body.write(chunk, idx, "binary");
idx += chunk.length;
});
response.on('end', function () {
res.contentType = 'image/jpg';
res.send(body);
});
}
});
reqGet.on('error', function (e) {
// Send default image if error
var file = 'img/user.png';
fs.stat(file, function (err, stat) {
var img = fs.readFileSync(file);
res.contentType = 'image/png';
res.contentLength = stat.size;
res.end(img, 'binary');
});
});
reqGet.end();
return next();
}
This may be a bit off-topic, since you are asking about static file serving via Node.js specifically (where fs.createReadStream('./image/demo.jpg').pipe(res) is actually a good idea), but in production you may want to have your Node app handle tasks, that cannot be tackled otherwise, and off-load static serving to e.g Nginx.
This means less coding inside your app, and better efficiency since reverse proxies are by design ideal for this.
This method works for me, it's not dynamic but straight to the point:
const fs = require('fs');
const express = require('express');
const app = express();
app.get( '/logo.gif', function( req, res ) {
fs.readFile( 'logo.gif', function( err, data ) {
if ( err ) {
console.log( err );
return;
}
res.write( data );
return res.end();
});
});
app.listen( 80 );
Let me just add to the answers above, that optimizing images, and serving responsive images helps page loading times dramatically since >90% of web traffic are images. You might want to pre-process images using JS / Node modules such as imagemin and related plug-ins, ideally during the build process with Grunt or Gulp.
Optimizing images means processing finding an ideal image type, and selecting optimal compression to achieve a balance between image quality and file size.
Serving responsive images translates into creating several sizes and formats of each image automatically and using srcset in your HTML allows you to serve optimal image set (that is, the ideal format and dimensions, thus optimal file size) for every single browser).
Image processing automation during the build process means incorporating it up once, and presenting optimized images further on, requiring minimum extra time.
Some great read on responsive images, minification in general, imagemin node module and using srcset.
//This method involves directly integrating HTML Code in the res.write
//first time posting to stack ...pls be kind
const express = require('express');
const app = express();
const https = require('https');
app.get("/",function(res,res){
res.write("<img src="+image url / src +">");
res.send();
});
app.listen(3000, function(req, res) {
console.log("the server is onnnn");
});
import http from "node:http";
import fs from "node:fs";
const app = http.createServer((req, res)=>{
if(req.url === "/" && req.method === "GET"){
res.writeHead(200, {
"Content-Type" : "image/jpg"
})
fs.readFile("sending.jpg", (err, data)=>{
if(err){
throw err;
}else{
res.write(data);
res.end();
}
})
}
}).listen(8080, ()=>{
console.log(8080)
})