How To Signal Eof To Node.js Stdin From Console?
I have a simple node.js app to echo stdin. When I run it interactively on the Windows console, I expected control-Z to be recognised as an EOF signal. But it isn't. So how do I
Solution 1:
the problem is you're using process.stdin.on
instead of process.on()
See the fix I made here and everything should be fine and dandy :) Enjoy!
process.stdin.setEncoding('utf-8');
console.log("input is a TTY?:", process.stdin.isTTY);
process.stdin.on('readable',function() {
var vText = process.stdin.read();
if (vText != null)
console.log('echo: "%s"',vText);
process.stdout.write('> '); // prompt fornext
});
process.on('SIGINT', function() {
console.log('Over and Out!');
process.exit(0);
});
Also I replaced 'end'
with 'SIGINT'
as that's the signal that is caught by CTRL+C
You can read about the signal events here: https://nodejs.org/api/process.html#process_signal_events
Solution 2:
It would appear the solution is to use readline
. This is more terminal-aware, and treats an interactive TTY ctrl-D as EOF, while also handling redirected input streams correctly. Also, being line oriented/aware, it conveniently strips newlines from the input strings.
var readline = require('readline');
process.stdin.setEncoding('utf-8');
console.log("input is a TTY?",process.stdin.isTTY);
var rl = readline.createInterface({input: process.stdin, output: process.stdout});
rl.setPrompt('> ');
rl.prompt();
rl.on('line' ,function(aText) { console.log('echo: "%s"',aText); rl.prompt(); });
rl.on('close',function() { console.log('input has closed'); /* ... */ });
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