I am trying to get header of get request. But i receive the error:

TypeError: request.getHeader is not a function
    at Server.<anonymous> (/home/pi/progs/smarthome/Site/cpu.js:8:27)
    at Server.emit (events.js:198:13)
    at parserOnIning (_http_server.js:695:12)
    at HTTPParser.parserOnHeadersComplete (_http_mon.js:111:17)

here is my code:

var http = require("http");
var fs =  require("fs");

var server = http.createServer(function(request, response) {

    var temp = fs.readFileSync("/sys/class/thermal/thermal_zone0/temp");
    var temp_c = temp/1000;

    var header = request.getHeader('Content-Type');
    console.log(header);

    response.writeHead(200, {"Content-Type": "text/plain"});
    response.write("Raspberry Pi cpu temperature: ");
    response.write("\n" + temp);
    response.write("\n" + temp_c);
    response.end();
});
server.listen(8080);

What am I doing wrong?

I am trying to get header of get request. But i receive the error:

TypeError: request.getHeader is not a function
    at Server.<anonymous> (/home/pi/progs/smarthome/Site/cpu.js:8:27)
    at Server.emit (events.js:198:13)
    at parserOnIning (_http_server.js:695:12)
    at HTTPParser.parserOnHeadersComplete (_http_mon.js:111:17)

here is my code:

var http = require("http");
var fs =  require("fs");

var server = http.createServer(function(request, response) {

    var temp = fs.readFileSync("/sys/class/thermal/thermal_zone0/temp");
    var temp_c = temp/1000;

    var header = request.getHeader('Content-Type');
    console.log(header);

    response.writeHead(200, {"Content-Type": "text/plain"});
    response.write("Raspberry Pi cpu temperature: ");
    response.write("\n" + temp);
    response.write("\n" + temp_c);
    response.end();
});
server.listen(8080);

What am I doing wrong?

• javascript
• node.js
• get
• raspberry-pi

4 Answers 4

Your req.getHeader() is not working because there is no method inside the ining http message object. You are getting an http.IningMessage object which does not have a req.getHeader(). Doc

Neither of these worked for me. I was trying to access a header inside a NextJS Serverless Function, on Vercel. Instead, I was able to get the header with this:

req.headers['header_name']

Insted of using getHeader, you can use :

 var header = request.header.get('Content-Type');
console.log(header);

req.headers['header_name'] really works and the reason is following:

As Ashish Rawat mentioned above in your http.createServer(function(request, response)... construction the 'request' is not http.ClientRequest but http.IningMessage class instance.

So http.ClientRequest.getHeader() method can't be applied here. Instead there's http.IningMessage.headers object. The reason why the way to access 'content-type' key is so unusial is '-' symbol in the middle of 'content-type'. You can access any other key without '-' as usual: req.headers.host, req.headers.connection, req.headers.origin, but in other cases it would be req.headers['bla-bla'] instead: req.headers['content-length'], req.headers['content-type'], req.headers['user-agent'] etc.