Listen to the close session of the terminal session

Question

In the terminal, I start the background process A, which, in turn, starts the process B. Process B writes to the terminal (process A passed B the correct TTY file descriptor).

I am afraid if the user (in some cases, I) closes the terminal window without sending process A or B a SIGINT. Then it may happen that process B still tries to write to the terminal, even if it was closed by the user. Worse, the user can open a new terminal window, and he can accept the same identifier / file as another terminal, and then is recorded in process B.

Basically, I'm looking for a way to “listen” for terminal session events, such as closing terminal sessions.

Is it possible to listen for such events inside the Node.js process? Perhaps there is an appropriate handler like process.on('SIGINT') ?

I assumed that the SIGTERM event was an event to listen to, but now, after experimenting with the code, don't think that it is.

Answer 1

You should look for SIGHUP (see also all possible signals ):

 var http = require('http'); var fs = require('fs'); var server = http.createServer(function (req, res) { setTimeout(function () { //simulate a long request res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }, 4000); }).listen(9090, function (err) { console.log('listening http://localhost:9090/'); console.log('pid is ' + process.pid); }); process.on('SIGHUP', function () { fs.writeFileSync(`${process.env.PWD}/sighup.txt`, `It happened at ${new Date().toJSON()}`); server.close(function () { process.exit(0); }); });