【发布时间】：2011-09-08 22:17:02
【问题描述】：
我是一位经验丰富的程序员，我最近才发现了 node.js。我喜欢 JavaScript，因为那是我开始的地方（Web 开发），所以能够用它编写服务器端代码真是太棒了。
目前，我正在做一个简单的练习，一个 WebSocket/HTTP 服务器，当我遇到一个小烦恼时，我开始添加目录列表功能：当我列出某个目录中的目录和文件时，它们是没有任何顺序。我希望它们首先列出目录，然后按字母顺序列出文件（如“ls”命令）。我有一种感觉，因为它是异步的，但我并不完全积极。任何帮助将不胜感激。
顺便说一句，这是我的代码：
var sys = require("sys");
var ws = require('websocket-server');
var fs = require("fs");
var path = require("path");
var url = require("url");
function log(data){
sys.log("\033[0;32m"+data+"\033[0m");
}
var server = ws.createServer();
server.listen(3400);
log("Listening on 3400 for HTTP and WS");
server.addListener("request", function(request, response){
log("HTTP: Connected: " + request.connection.remoteAddress);
var uri = url.parse(request.url).pathname;
var filename = path.join("/home/brandon", uri);
log("HTTP: " + request.connection.remoteAddress + " Requested: " + filename);
path.exists(filename, function(exists) {
if(!exists) {
response.writeHead(404, {"Content-Type": "text/plain"});
response.write("404 Not Found\n");
log("HTTP: " + filename + " Does Not Exist. 404 returned to " + request.connection.remoteAddress);
response.end();
log("HTTP: Disconnected: " + request.connection.remoteAddress);
return;
}
fs.readFile(filename, "binary", function(err, file) {
if(err) {
if(err.errno === 21){
fs.readdir(filename, function(err1, files){
if(err1){
response.writeHead(500, {"Content-Type": "text/plain"});
response.write("Error when reading directory: " + err1 + "\n");
log("HTTP: " + filename + " Could Not Be Read. 500 returned to " + request.connection.remoteAddress);
response.end();
log("HTTP: Disconnected: " + request.connection.remoteAddress);
return;
} else {
response.writeHead(200);
response.write("<HTML><HEAD><title>Directory Listing for " + uri + "</title></HEAD><BODY><h1>Directory Listing for " + uri + "</h1>");
response.write("<ul>");
function printBr(element, index, array) {
response.write("<li>" + element + "</li>");
}
/*for( i in files ){
response.write("<li>" + files[i] + "</li>");
}*/
files.forEach(printBr);
response.write("</ul>");
response.write("</BODY></HTML>");
log("HTTP: Directory listing for " + filename + " sent to " + request.connection.remoteAddress);
response.end();
log("HTTP: Disconnected: " + request.connection.remoteAddress);
return;
}
});
return;
}
response.writeHead(500, {"Content-Type": "text/plain"});
response.write("Error when reading file: " + err + "\n");
log("HTTP: " + filename + " Could Not Be Read. 500 returned to " + request.connection.remoteAddress);
response.end();
log("HTTP: Disconnected: " + request.connection.remoteAddress);
return;
}
response.writeHead(200);
response.write(file, "binary");
log("HTTP: " + filename + " Read and Sent to " + request.connection.remoteAddress);
response.end();
log("HTTP: Disconnected: " + request.connection.remoteAddress);
});
});
});
server.addListener("connection", function(conn){
log(conn.id + ": new connection");
server.broadcast("New Connection: "+conn.id);
conn.addListener("readyStateChange", function(readyState){
log("stateChanged: "+readyState);
});
conn.addListener("close", function(){
var c = this;
log(c.id + ": Connection Closed");
server.broadcast("Connection Closed: "+c.id);
});
conn.addListener("message", function(message){
log(conn.id + ": "+JSON.stringify(message));
server.broadcast(conn.id + ": "+message);
});
});
这是浏览器中的输出：
**已解决：**
感谢@Samir，我知道了如何做我想做的事。我遍历目录内容的数组，检查一个项目是目录还是文件，将它们分成两个数组（'dirs_in' 用于 dirs 和 'files_in' 用于文件），按字母顺序对两个数组进行排序，最后将它们写出来.
代码（第 42-70 行）：
response.writeHead(200);
response.write("<HTML><HEAD><title>Directory Listing for " + uri + "</title></HEAD><BODY><h1>Directory Listing for " + uri + "</h1>");
response.write("<ul>");
function printBr(element, index, array) {
response.write("<li>" + element);
if( fs.statSync( path.join(filename + element) ).isDirectory() ){
response.write(" is a <b>dir</b>");
} else {
response.write(" is a <b>file</b>");
}
response.write("</li>");
}
var dirs_in = [];
var files_in = [];
function sep(element, index, array) {
if( fs.statSync( path.join(filename + element) ).isDirectory() ){
dirs_in.push(element);
} else {
files_in.push(element);
}
}
files.forEach(sep);
dirs_in.sort().forEach(printBr);
files_in.sort().forEach(printBr);
response.write("</ul>");
response.write("</BODY></HTML>");
log("HTTP: Directory listing for " + filename + " sent to " + request.connection.remoteAddress);
response.end();
log("HTTP: Disconnected: " + request.connection.remoteAddress);
浏览器输出： 附言我将删除“是目录”和“是文件”。它们只是为了测试。
【问题讨论】：
-
即使回答了这个问题，也许您可以定义“按顺序”列出目录中的文件意味着什么？
-
statSync并不便宜，并且会在您的代码中造成可怕的瓶颈。不要在 Web 服务器中使用Sync函数。 -
您可以尝试here7 给出的解决方案 为什么要重建轮子？ ;)
标签： javascript list node.js directory inorder