View random ngrok URL when run in background

Question

When I start an ngrok client with ./ngrok tcp 22 it runs in the foreground and I can see the randoming generated forwarding URL, such as tcp://0.tcp.ngrok.io:

Answer 1

A Node.js solution.

Bonus: It copies the url to the clipboard in Windows, Mac and Linux¹

const http = require("http");
const { execSync } = require("child_process");

const callback = (res) => {
    let data = "";
    res.on("data", (chunk) => (data += chunk));
    res.on("end", () => {
        const resJSON = JSON.parse(data);
        const tunnels = resJSON.tunnels;

        const { public_url: url } = tunnels.find(({ proto }) => proto === "https");

        console.log(url);

        // Copy to clipboard
        switch (process.platform) {
            case "win32":
                execSync(`echo ${url} | clip`);
                break;
            
            case "darwin":
                execSync(`echo ${url} | pbcopy`);
                break;
                
            case "linux":
                // NOTE: this requires xclip to be installed
                execSync(`echo ${url} | xclip -selection clipboard`);
                break;
                
            default:
                break;
        }
    });
};

http.get("http://localhost:4040/api/tunnels", callback);

[1] You need to install xclip first:

sudo apt-get install xclip