node.js教程learnyounode 闯关答案

#node.js教程learnyounode 闯关答案
#ex1
console.log("HELLO WORLD");

#ex2
var sum =0;
for(var i =2;i<process.argv.length;i+=){
	sum+=parseFloat(process.argv[i]);
}
console.log(sum);

#ex3 
var fs = require(‘fs‘);
var pathname = process.argv[2];
//console.log(pathname);

var buf = fs.readFileSync(pathname);
var results = buf.toString().split("\n");
//console.log(results);
console.log(results.length-1);

#ex4
var fs = require(‘fs‘);
var pathname = process.argv[2];

fs.readFile(pathname,handle);
function handle(err,data){
	if(err){
		console.error(err);
		return;
	}
	var results = data.toString().split("\n");
	console.log(results.length-1);
}

#ex5
var fs = require(‘fs‘);
var path = require(‘path‘);
var pathname = process.argv[2];
var extname = process.argv[3];

fs.readdir(pathname,function(err,files){
	for(var i=0;i<files.length;i++){
		if("."+extname == path.extname(files[i])){
			console.log(files[i]);
		}
	}
});

#ex6
##program.js
var mymodule = require("./mymodule");
var pathname = process.argv[2];
var extname = process.argv[3];
mymodule(pathname,extname,callback);

function callback(err,data){
	if(err){
		console.error(err);
		return ;
	}
	data.forEach(function(file){
		console.log(file);
	});
}
##mymodule.js
var fs = require(‘fs‘);
var path = require(‘path‘);
module.exports = function (pathname,extname,callback){
	var results = new Array();
	var cnt =0;
	fs.readdir(pathname,function(err,files){
		if(err){
			return callback(err);
		}
		for(var i=0;i<files.length;i++){
			if("."+extname == path.extname(files[i])){
				results[cnt++] = files[i];
			}
		}
		//console.log(results);
		callback(null,results);
	});	
};

#ex7
var http = require("http");

var url = process.argv[2];

http.get(url, function(res) {
	res.setEncoding("utf-8");
	res.on("data",function(data){
		console.log(data);
	});
});

#ex8
var http = require("http");

var url = process.argv[2];

http.get(url, function(res) {
	res.setEncoding("utf-8");
	var results ="";
	res.on("data",function(data){
		results +=data;
	});
	res.on("end",function(){
		console.log(results.length);
		console.log(results);
	});
});

#ex9
#solution1:
var http = require("http");
http.get(process.argv[2],handle1);
http.get(process.argv[3],handle2);
http.get(process.argv[4],handle3);
var results= ["","",""];
function handle1(res){
	res.setEncoding="utf-8";
	res.on("data",function(data){
		results[0] +=data;
	});
	res.on("end",function(){
		//console.log(results[0]);
	});
}
function handle2(res){
	res.setEncoding="utf-8";
	res.on("data",function(data){
		results[1] +=data;
	});
	res.on("end",function(){
		//console.log(results[1].toString());
	});
}
function handle3(res){
	res.setEncoding="utf-8";
	res.on("data",function(data){
		results[2] +=data;
	});
	res.on("end",function(){
		console.log(results[0].toString());
		console.log(results[1].toString());
		console.log(results[2].toString());
	});
}
#solution2:
var http = require("http");

var results=[];
var count =0;
for(var i=0;i<3;i++){
	httpGet(i);
}
function httpGet(index){
	http.get(process.argv[index+2],function(res){
		res.setEncoding="utf-8";
		results[index]="";
		res.on("data",function(data){
			results[index] +=data;
		});
		res.on("end",function(){
			count++;
			if(count>=3){
				for(var i=0;i<results.length;i++){
					console.log(results[i]);
				}
			}
		});
		
	});
}

##参考答案
 var http = require(‘http‘)
 var bl = require(‘bl‘)
 var results = []
 var count = 0

 function printResults () {
   for (var i = 0; i < 3; i++)
     console.log(results[i])
 }

 function httpGet (index) {
   http.get(process.argv[2 + index], function (response) {
     response.pipe(bl(function (err, data) {
       if (err)
         return console.error(err)

       results[index] = data.toString()
       count++

       if (count == 3)
         printResults()
     }))
   })
 }

 for (var i = 0; i < 3; i++)
   httpGet(i)


#ex10
var net = require("net");

var port = process.argv[2];
var server = net.createServer(function(socket){
	socket.end(getTime()+"\n");
});
server.listen(port);
console.log("Server started http://127.0.0.1:%s",port)

function getTime(){
	var date = new Date();
	var year = date.getFullYear();
	var month = justify(date.getMonth()+1);
	var day = justify(date.getDate());
	var hour = justify(date.getHours());
	var minute = justify(date.getMinutes());
	return year + "-"+month+"-"+day+" "+hour+":"+minute;
}

function justify(str){
	return str<10?"0"+str:str;
}

#ex11
var http = require("http");
var fs = require("fs");
var server = http.createServer(function(req,res){
	res.writeHead(200,{"content-type":"text/plain"});
	fs.createReadStream(process.argv[3]).pipe(res);
});
server.listen(process.argv[2]);

#ex12
var http = require("http");
http.createServer(function(req,res){
	var post = "";
	req.on(‘data‘,function(chunk){
		post += chunk;
	});
	req.on(‘end‘,function(){
		post = post.toUpperCase();
		res.end(post);
	});
}).listen(process.argv[2]);
#参考答案：
var http = require(‘http‘)
var map = require(‘through2-map‘)

var server = http.createServer(function (req, res) {
  if (req.method != ‘POST‘)
    return res.end(‘send me a POST\n‘)

  req.pipe(map(function (chunk) {
    return chunk.toString().toUpperCase()
  })).pipe(res)
})

server.listen(Number(process.argv[2]))


#ex13
var http = require("http");
var url = require("url");

http.createServer(function(req,res){
	var url2 = url.parse(req.url,true);
	var pathname = url2.pathname;
	var iso = url2.query.iso;
	var date = new Date(iso);
	var result;
	res.writeHead(200,{"Content-Type":"application/json"});
	if(pathname == "/api/parsetime"){
		result = {
			"hour":date.getHours(),
			"minute":date.getMinutes(),
			"second":date.getSeconds()
		};
		res.end(JSON.stringify(result));
	}else if(pathname == "/api/unixtime"){
		result = {
			"unixtime":date.getTime()
		};
		res.end(JSON.stringify(result));
	}
}).listen(process.argv[2]);

来自为知笔记(Wiz)