URL Scanner in Node

url_scan.js

var fs = require('fs');
var readline = require('readline');
var http = require('http');
var timeout = 2;  // Timeout in seconds.

var rd = readline.createInterface({
    input: fs.createReadStream('tenthousand_urls.txt'),
    output: process.stdout,
    terminal: false
});

function processResponse(res) {
    var code = res.statusCode;
    var requestedHost = res.req.getHeader('host');
    var redirectedHost = res.headers['location'];

    if (code >= 200 && code <= 299) {
        console.log('2XX: ' + requestedHost);
    } else if (code >= 300 && code <= 399) {
        console.log('3XX: ' + requestedHost + ' -> ' + redirectedHost);
    } else if (code >= 400 && code <= 499) {
        console.log('4XX: ' + requestedHost);
    } else if (code >= 500 && code <= 599) {
        console.log('5XX: ' + requestedHost);
    } else {
        console.log(code + ': ' + requestedHost);
    }

}


function getUrl(hostname, port) {
    var options = {method: 'HEAD', hostname: hostname, port: port};
    var req = http.request(options);

    req.on('response', processResponse);
    req.on('error', function(e) {});
    req.setTimeout(timeout * 1000, req.abort);
    req.end();
}


rd.on('line', function(line) {
    switch(line) {
        case line[0] === '#':
            break;

        case line === '':
            break;

        case line.slice(0, 4) !== 'http':
            break;

        default:
            if (line.slice(0, 5) === 'http:') {
                getUrl(line.slice(7), 80);
            }

            if (line.slice(0, 5) === 'https') {
                getUrl(line.slice(8), 443);
            }
    }

});