I stumbled upon this because I was having trouble taking down a Vite dev server in an Sbt task. The Vite Dev server is a bit finicky, and may stay alive even after killing the parent process. That is, if you start vite with something like this (or an equivalent program in a different programming language):

import cp from 'node:child_process';
console.log("Spawning Vite Dev server...");
const p = cp.exec('npx vite');
p.stdout.pipe(process.stdout);
p.stderr.pipe(process.stderr);
console.log("Shutting down in 5 seconds");
await new Promise((resolve) => setTimeout(resolve, 5000));
console.log("Shutting down Vite Dev server...");
p.kill();

Calling kill won't destroy the server worker process. Not even trying to use the terminal UI by sending "q\n" to stdin will make a difference.

The only way that allowed me to have full control of the dev server's lifetime was to spawn a custom script which uses the Vite API directly and actively detects whether it should stop. For instance, if I want this server to live for as long as there is another server listening on local port 9000:

import { createServer } from 'vite';
import net from 'node:net';
import url from 'node:url';
console.log("Spawning Vite Dev server...");
const server = await createServer();
await server.listen(5173);
server.printUrls();
const checkPlayServer = async () => {
 // check if the server is still alive
 let socket = net.connect({
 port: 9000,
 host: 'localhost',
 });
 socket.on('error', async (err) => {
 console.log("Closing Vite Dev server");
 socket.destroy();
 await server.close();
 })
 socket.on('connect', () => {
 socket.end();
 // connection still OK, resuming pinging
 setTimeout(checkPlayServer, 2_500);
 })
};
setTimeout(checkPlayServer, 2_500);

just use this command:
npx kill-port 5173

npx vite then q + enter worked for me

Kill the process and all of its children: pkill -TERM -P [PID]
example:

if yarn vite > /dev/null; then
 pid=$!
 // do something else
 if ! pkill -TERM -P $pid; then echo "UNABLE TO KILL THE PROCESS! PID: $pid"
fi

Generally this is not needed, as most server software worth its salt has a "stop" command to prevent the user from ungracefully terminating the server process. I could not find any documentation for Vite detailing such a mechanism. It would seem that the developers for Vite have decided that a SIGINT is enough.... which if you've worked with servers before you'd know is not always the case.