Node.js Domain sample

domain_sample.js

var fs = require('fs');
var domain = require('domain');

function countChars(filename, callback) {
    var d = domain.create().on('error', function (err) {
	callback(err);
    });
    fs.readFile(filename, 'utf-8', d.intercept(function (_, data) {
	callback(null, data.length);
    }));
}

function main(args) {
    var d = domain.create().on('error', function (err) {
	console.error(err);
    });
    countChars(args[0], d.intercept(function (_, length) {
	console.log(length);
    }));
}

main(['path1']);