Electron - Detect and handle SIGINT/SIGTERM Signals in Linux

Question

You can listen for SIGINT/SIGTERM and stop your app from exiting when the User presses CTRL-C in the terminal (if it was launched from one) in node js using process.on, but the same did not work in my electron application. I also tried binding handlers to the "quit", "before-quit" and "will-quit" events of the app object but to no avail. Is it possible to detect if the user opened the app from the terminal and pressed CTRL-C in an electron app, and to bind handlers to it and stop the app from exiting. And if yes, then how would you achieve this?

Here's how I am using process.on and app.on in a basic electron Main Process, in case I am doing something wrong (my original script contains alot of code not relevant to the question and what I want to achieve does not work with basic electron-quickstart app either):

const { app, BrowserWindow } = require("electron");
const path = require("path");

function createWindow() {
    const win = new BrowserWindow({
        width: 800,
        height: 600,
        webPreferences: {
            preload: path.join(__dirname, "preload.js"),
        },
    });

    win.loadFile("index.html");
}

app.whenReady().then(() => {
    createWindow();

    app.on("activate", function () {
        if (BrowserWindow.getAllWindows().length === 0) createWindow();
    });
});

app.on("will-quit", (e) => {
    console.log("App recieved request to quit");
    e.preventDefault();
});

app.on("before-quit", (e) => {
    console.log("App recieved request to quit");
    e.preventDefault();
});

app.on("quit", (e) => {
    console.log("App recieved request to quit");
    e.preventDefault();
});

process.on("SIGINT SIGTERM", () => {
    console.log("Detected SIGINT/SIGTERM");
});

process.on("SIGTERM", () => {
    console.log("Detected SIGTERM");
});

This question concerns Linux only.

Answer 1

You're registering the event listeners too early. I modified your code to include all the listeners in the block after whenReady and got the results you were expecting.