用nodejs的express框架在本机快速搭建一台服务器

function sleep(sleepTime) {
    for(var start = +new Date; +new Date - start <= sleepTime; ) { } 
}

function exec_cmd(cmdStr) {
    var exec = require('child_process').exec;
    exec(cmdStr, function(err,stdout,stderr){
        if(err) {
            console.log('Error:'+stderr);
        } else {
            console.log(stdout);
        }
    });
}

var express = require('express');
var app = express();
var path = require('path');
console.log(path.join(__dirname, '/'));
app.use(express.static(path.join(__dirname, '/')));
var distribution = '/static/html/distribution.html'

app.get("/distribution", function (req, res) {
    var cmdStr = 'python scripts/check_tasks_distribution.py';
    exec_cmd(cmdStr);
    var fs = require("fs");
    fs.exists(path.join('static', 'html', 'distribution.html'), function(exists) {  
        if (exists) {
            res.redirect(distribution);
        } else {
            exec_cmd(cmdStr);
            sleep(1000);
        }
    });
});

var server = app.listen(3000, function () {
    var host = server.address().address;
    var port = server.address().port;
    console.log('Listening at http://%s:%s', host, port);
});