Question

php中fgetc（）函数的Node.js等价物是什么？我将如何将其应用于套接字？

我正在使用这个php脚本的node.js端口： http://code.google.com/p/bf2php/source/browse/trunk/rcon/BF2RConBase.class.php

基本上它使用套接字连接到基于战地2的游戏服务器。我正在看的功能是：

protected function read($bare = false) {
    $delim = $bare ? "\n" : "\x04";
    for($buffer = ''; ($char = fgetc($this->socket)) != $delim; $buffer .= $char);
    return trim($buffer);
}

它应该直接从套接字（从我收集的信息）中抓取第一行一次一个字符直到'\ n'。我假设输出用于获取加密盐。该函数在套接字连接事件中被调用，作为生成登录所需加密密码的代码的一部分。任何人都可以告诉我这个函数的Node.js等价物是什么样的吗？

Answer 1

docs有一个很好的例子，说明如何通过网络连接到服务器。

var net = require('net');
var client = net.connect({port: 8124},
    function() { //'connect' listener
  console.log('client connected');
  client.write('world!\r\n');
});
client.on('data', function(data) {
  console.log(data.toString());
  client.end();
});
client.on('end', function() {
  console.log('client disconnected');
});

只需更改data事件处理程序即可缓冲传入的数据，直到您收到所需的信息为止。

为此，您需要知道如何使用Buffer。

这是一个如何从流缓冲数据并解析由特定字符分隔的消息的具体示例。我在链接的PHP中注意到您尝试实现的协议使用EOT（0x04）字符来分隔消息。

var net = require('net');


var max = 1024 * 1024 // 1 MB, the maximum amount of data that we will buffer (prevent a bad server from crashing us by filling up RAM)
    , allocate = 4096; // how much memory to allocate at once, 4 kB (there's no point in wasting 1 MB of RAM to buffer a few bytes)
    , buffer=new Buffer(allocate) // create a new buffer that allocates 4 kB to start
    , nread=0 // how many bytes we've buffered so far
    , nproc=0 // how many bytes in the buffer we've processed (to avoid looping over the entire buffer every time data is received)
    , client = net.connect({host:'example.com', port: 8124}); // connect to the server

client.on('data', function(chunk) {
    if (nread + chunk.length > buffer.length) { // if the buffer is too small to hold the data
        var need = Math.min(chunk.length, allocate); // allocate at least 4kB
        if (nread + need > max) throw new Error('Buffer overflow'); // uh-oh, we're all full - TODO you'll want to handle this more gracefully

        var newbuf = new Buffer(buffer.length + need); // because Buffers can't be resized, we must allocate a new one
        buffer.copy(newbuf); // and copy the old one's data to the new one
        buffer = newbuf; // the old, small buffer will be garbage collected
    }

    chunk.copy(buffer, nread); // copy the received chunk of data into the buffer
    nread += chunk.length; // add this chunk's length to the total number of bytes buffered

    pump(); // look at the buffer to see if we've received enough data to act
});

client.on('end', function() {
    // handle disconnect
});


client.on('error', function(err) {
    // handle errors
});


function find(byte) { // look for a specific byte in the buffer
    for (var i = nproc; i < nread; i++) { // look through the buffer, starting from where we left off last time
        if (buffer.readUInt8(i, true) == byte) { // we've found one
            return i;
        }
    }
}
function slice(bytes) { // discard bytes from the beginning of a buffer
    buffer = buffer.slice(bytes); // slice off the bytes
    nread -= bytes; // note that we've removed bytes
    nproc = 0; // and reset the processed bytes counter
}

function pump() {
    var pos; // position of a EOT character

    while ((pos = find(0x04)) >= 0) { // keep going while there's a EOT (0x04) somewhere in the buffer
        if (pos == 0) { // if there's more than one EOT in a row, the buffer will now start with a EOT
            slice(1); // discard it
            continue; // so that the next iteration will start with data
        }
        process(buffer.slice(0,pos)); // hand off the message
        slice(pos+1); // and slice the processed data off the buffer
    }
}

function process(msg) { // here's where we do something with a message
    if (msg.length > 0) { // ignore empty messages
        // here's where you have to decide what to do with the data you've received
        // experiment with the protocol
    }
}

完全未经测试，因此可能存在错误。这里收集的主要内容是，当数据到达时，您将其缓冲在内存中。一旦在缓冲区中找到分隔符，就可以处理该消息。

对于Node.js socket来说，php的fgetc（）相当于什么？

1 个答案: