用NodeJS／express-4.0实现的静态文件服务器（serveStatic插件直接支持HTTP Range请求，因此可用来做mp4流媒体服务器）

var express = require('express'),
serveIndex = require('serve-index'), //只能列表目录，不能下载文件？
serveStatic = require('serve-static')
;

/*
$ brew install node@8.4.0
不使用package.json的依赖安装方法：以全局模式（-g）安装npm依赖，然后npm link命令创建符号链接
$ npm install express -g
$ npm link express
*/

var LOCAL_BIND_PORT = 3000; //express's port

var app = express()
app.set('x-powered-by', false)
app.set('strict routing', true); //路径/a与/a/是不一样的（但是/a/*需要单独指出吗？）
app.set('trust proxy', true); //与Nginx反向代理配合使用？

//Trick:
app.getOrPost = function(urlPattern, callback){
app.get(urlPattern, callback);
app.post(urlPattern, callback);
}

var REQUEST_GLOBAL_NUM = 1;
app.use(function requestNumbering(req, res, next){
var this_request_id = REQUEST_GLOBAL_NUM++; //for dump data file naming;
req.request_id = (""+this_request_id).padStart(10, "0")
next()
})

app.use(function addServerSideIPAddress(req, res, next){//log输出req.headers，FIXME：怎么log输出最终的res.headers？
//console.log("["+req.request_id+"] logReqHeaders: req.ip=" + req.ip+" req.socket.localAddress="+req.socket.localAddress);
//req.socketLocalIPv4Address = req.socket.localAddress.replace("::ffff:","").replace("::1","127.0.0.1")
//dirty hack to fix OS IPv6-first to use IPv4 address only
console.log("["+req.request_id+"] req.headers: "+JSON.stringify(req.headers, null, 2));
next();
})

//目录列表及静态文件下载
app.get("/", function(req, res){
res.redirect(302, "/f"); //test direct;
});

app.use('/f', serveIndex('/Users/chenzhixiang/', {'icons': true})) //This is Mac OS fs path;
var serve = serveStatic('/Users/chenzhixiang/')
app.get('/f/*', function(req, res){
req.url = req.url.substring(2); //跳过url中的/f前缀，把剩余的部分映射为相对于/home/chenzx的文件路径
console.log("["+req.request_id+"] GET static "+req.url);
serve(req, res)
});

console.log(`Start static file server at ::${LOCAL_BIND_PORT}, Press ^ + C to exit`)
app.listen(LOCAL_BIND_PORT)