node.js – Page 256 – Tarik Billa

Node.js getaddrinfo ENOTFOUND

September 24, 2022 by Tarik

In Node.js HTTP module’s documentation: http://nodejs.org/api/http.html#http_http_request_options_callback You can either call http.get(‘http://eternagame.wikia.com/wiki/EteRNA_Dictionary’, callback), the URL is then parsed with url.parse(); or call http.get(options, callback), where options is { host: ‘eternagame.wikia.com’, port: 8080, path: ‘/wiki/EteRNA_Dictionary’ } Update As stated in the comment by @EnchanterIO, the port field is also a separate option; and the protocol http:// shouldn’t … Read more

Can pm2 run an ‘npm start’ script

September 24, 2022 by Tarik

PM2 now supports npm start: pm2 start npm — start To assign a name to the PM2 process, use the –name option: pm2 start npm –name “app name” — start

What is the parameter “next” used for in Express?

September 24, 2022 by Tarik

It passes control to the next matching route. In the example you give, for instance, you might look up the user in the database if an id was given, and assign it to req.user. Below, you could have a route like: app.get(“https://stackoverflow.com/users”, function(req, res) { // check for and maybe do something with req.user }); … Read more

How do I determine the current operating system with Node.js

September 24, 2022 by Tarik

The variable to use would be process.platform On Mac the variable is set to darwin. On Windows, it is set to win32 (even on 64 bit). Current possible values are: aix darwin freebsd linux openbsd sunos win32 android (Experimental, according to the link) I just set this at the top of my jakeFile: var isWin … Read more

`npm install` fails on node-gyp rebuild with `gyp: No Xcode or CLT version detected!`

September 23, 2022 by Tarik

Even though you have them installed (my case), but by upgrading to Catalina (10.15.*) you can get this error (my case 🙂 ). Therefore, simply installing wouldn’t help as you will get an error that they are already installed. Therefore you need to hopefully just (I) reset the tool or in worse case (II) uninstall … Read more

Detect if called through require or directly by command line

September 23, 2022 by Tarik

if (require.main === module) { console.log(‘called directly’); } else { console.log(‘required as a module’); } See documentation for this here: https://nodejs.org/docs/latest/api/modules.html#modules_accessing_the_main_module

node.js require() cache – possible to invalidate?

September 23, 2022 by Tarik

You can always safely delete an entry in require.cache without a problem, even when there are circular dependencies. Because when you delete, you just delete a reference to the cached module object, not the module object itself, the module object will not be GCed because in case of circular dependencies, there is still a object … Read more

Express.js: how to get remote client address

September 23, 2022 by Tarik

If you are running behind a proxy like NGiNX or what have you, only then you should check for ‘x-forwarded-for’: var ip = req.headers[‘x-forwarded-for’] || req.socket.remoteAddress If the proxy isn’t ‘yours’, I wouldn’t trust the ‘x-forwarded-for’ header, because it can be spoofed.

Get all directories within directory nodejs

September 23, 2022 by Tarik

Promise import { readdir } from ‘fs/promises’ const getDirectories = async source => (await readdir(source, { withFileTypes: true })) .filter(dirent => dirent.isDirectory()) .map(dirent => dirent.name) Callback import { readdir } from ‘fs’ const getDirectories = (source, callback) => readdir(source, { withFileTypes: true }, (err, files) => { if (err) { callback(err) } else { callback( … Read more

How to install a private NPM module without my own registry?

September 23, 2022 by Tarik

In your private npm modules add “private”: true to your package.json Then to reference the private module in another module, use this in your package.json { “name”: “myapp”, “dependencies”: { “private-repo”: “git+ssh://git@github.com:myaccount/myprivate.git#v1.0.0”, } }