Nodejs中的Slurping TCP Echo服务器

我尝试制作一个简单的TCP echo服务器,它首先读取所有输入,然后再发送一个副本。

var net = require('net');

var server = net.createServer(function(socket) {
    socket.write('Echo server\r\n');

    //socket.pipe(socket)

    socket.UsrData='';
    socket.on('data', function(chunk){
            socket.UserData+=chunk;
    });
    socket.on('end', function(){
            console.log('end');
            socket.end(socket.UserData);
    });
});
server.listen(1337, 'localhost');

现在如果我用

nc  -q0 localhost 1337 </etc/profile

end
events.js:183
      throw er; // Unhandled 'error' event
      ^

Error: This socket has been ended by the other party
    at Socket.writeAfterFIN [as write] (net.js:364:12)
    at Socket.Writable.end (_stream_writable.js:563:10)
    at Socket.end (net.js:509:31)
    at Socket.<anonymous> (/home/petr/f/learn/nodejs/echo.js:20:11)
    at emitNone (events.js:111:20)
    at Socket.emit (events.js:208:7)
    at endReadableNT (_stream_readable.js:1064:12)
    at _combinedTickCallback (internal/process/next_tick.js:138:11)
    at process._tickCallback (internal/process/next_tick.js:180:9)

我该怎么修?

(

socat  TCP4-LISTEN:1337,reuseport,fork EXEC:'./slurp'

哪里 ./slurp

#!/bin/sh -eu
inp=$(cat)
printf '%s\n' "$inp"

)