You may recall I was inspired to write software emulating Enigma and the Bombe. Colin suggested I write it in Node.js. Node.js is some sort of JavaScript runtime thing that is event-driven. This is well out of my comfort zone: I have some learning to do.
Hello World
I made a start with that well-known program, Hello World.
In Node.js, it was remarkably easy: I created a file called helloworld.js containing the following code:
console.log('Hello World');.
To run this file, I typed:
$ node helloworld.js
at the command line to obtain this output:
Hello World.
Success!
Hello World — server edition
There is also a server version. I saved the following code in a file called helloworld_server.js:
const http = require('http');
const hostname = '127.0.0.1';
const port = 3000;
const server = http.createServer((req, res) => {
res.statusCode = 200;
res.setHeader('Content-Type', 'text/plain');
res.end('Hello World\n');
});
server.listen(port, hostname, () => {
console.log(`Server running at http://${hostname}:${port}/`);
});
At the command line, I typed:
$ node helloworld_server.js
and it output:
Server running at http://127.0.0.1:3000/.
This looked promising. I opened my browser and navigated to http://127.0.0.1:3000/; I was shown a page displaying:
Hello World.
Another success!
I opened a new command line window while the server was still running, and typed:
$ curl 127.0.0.1:3000,
which output:
Hello World.
More success!
(To quit the server, press ctrl-c.)
Now I just need to learn how to do all sorts of other things, and I’ll have my Enigma and Bombe machines built in no time.
