Express设置主机头

摘自 https://github.com/visionmedia/express/blob/master/examples/vhost/index.js 

/** * Module dependencies. */var express = require('../..');/*edit /etc/hosts:127.0.0.1       foo.example.com127.0.0.1       bar.example.com127.0.0.1       example.com*/// Main server appvar main = express();main.use(express.logger('dev'));main.get('/', function(req, res){  res.send('Hello from main app!')});main.get('/:sub', function(req, res){  res.send('requested ' + req.params.sub);});// Redirect appvar redirect = express();redirect.all('*', function(req, res){  console.log(req.subdomains);  res.redirect('http://example.com:3000/' + req.subdomains[0]);});// Vhost appvar app = express();app.use(express.vhost('*.example.com', redirect)) // Serves all subdomains via Redirect appapp.use(express.vhost('example.com', main)); // Serves top level domain via Main server app app.listen(3000);console.log('Express app started on port 3000');