所以我之前有一个问题here，它帮助我理解和解决了几件事。
我对套接字编程还是很陌生，现在遇到了一个新的错误。
当我将文件发送到客户端时，收到的文件始终无效。 (我正在尝试发送一个zip文件)。我也有大小问题，因为原始文件的大小为30Mb，但客户端收到的大小不同(字节不同)。这是正常的还是应该解决？
这是我的代码:
服务器:
char buf[4096];
/*Sending files and recvieing test...*/
std::string message = "Welcome to the server :)";
ZeroMemory(buf, 4096);
if (send(clientsocket, message.c_str(), 4096, 0) > 0) {
std::cout << "Sent to client successfully" << std::endl;
}
if (recv(clientsocket, buf, sizeof(buf), 0)) {
std::cout << "Recv: " << std::string(buf, 0, 4096)<<std::endl;
}
// File opening and sending.
std::ifstream file("C:\\test.zip", std::ios::in | std::ios::binary | std::ios::ate);
file.seekg(0, file.end);// get file size
unsigned long size = file.tellg();
file.seekg(0);
char* buffer = new char[size]; // buffer or memblock to hold the file.
file.read(buffer, size);// write to the buffer.
file.close();
//Conver the size into string to send it throu socket.
std::string siz;
std::stringstream str;
str << size;
str >> siz;
// send the file size and receive a message from client.
int byteSent = 0;
if (byteSent = send(clientsocket, siz.c_str(), 10, 0)) {
std::cout << byteSent << std::endl;
if (recv(clientsocket, buf, 4009, 0)) {
std::cout << std::string(buf, 0, 4096)<<std::endl;
}
}
/*File sending FTP*/
byteSent = 0;
int length=0;
while (length < size) {
if (byteSent = send(clientsocket, buffer, 1021 , 0)) { // tried few different sizes to send and client still got different size.
length += byteSent;
}
else
{
std::cout << "Connectionlost, Error: " << WSAGetLastError()<<std::endl;
}
std::cout << "Sending: " << length << " Size: " << size - length << "Left to send" << std::endl; // keep track of how many bytes was sent.
}
现在在客户端:
//Send and Recvied from server:
char buff[4096];
std::string message = "Recv is working";
int bytesR = 0;
int byteSent = 0;
int tot = 0;
ZeroMemory(buff, 4096);
if (bytesR = recv(server, buff, 4096, 0) > 0) {
std::cout << "Server >> " << std::string(buff, 0, 4096) << std::endl;
if (byteSent = send(server, message.c_str(), message.size(), 0) > 0) {
std::cout << "Sent successfully to server." << std::endl;
}
}
else {
std::cout << "No connection";
}
int sizz;
//Receiving size
std::string siz;
int len = 0;
char bufsize[200];
if (bytesR = recv(server, bufsize, sizeof(bufsize), 0)) {
std::cout << "Bytes Recvied: " << bytesR << std::endl;
siz = std::string(bufsize, 0, 4096);
std::cout << "File size recv: " << siz << std::endl;
sizz = std::stoi(siz);
std::cout << "Size recved to int: " << sizz << std::endl;
message = "Recvied size of file : " + std::string(buff, 0, 4096);
if (send(server, message.c_str(), message.size(), 0)) {
}
}
//Create the file after receiving the size.
std::ofstream file("test.zip", std::ofstream::binary);
char* filebuf = new char[sizz];
bytesR = 0;
int recvied = 0;
while (recvied < sizz) {
bytesR = recv(server, filebuf, 1021, 0);
if (bytesR > 0) {
file.write(filebuf, bytesR); // write the block of file received based on how many bytes received.
recvied += bytesR;
std::cout << "Reciveing... " << recvied << " out of: " << sizz << std::endl;// keeping track of received bytes.
}
else
{
std::cout << "Connecton lost, Error: " << WSAGetLastError() << std::endl;
break;
}
}
file.close();
因此，关于发送和接收的几乎所有疑问都说我不应该发送整个文件，因为它可能不会整体发送。但是通过循环发送整个文件，我能够发送超过1gb的文件并将其正确写入客户端。
我希望它足够清楚。我做了很少的修改，我相信这比我在另一个问题上所做的修改要好得多。
最佳答案
您犯了两个半错误。每次传输的数据包大小通常为1024字节缓冲区。许多人犯了不将系统值调整为该值的错误。 1.5 x错误是您没有足够地考虑\r\n两者。服务器端while(长度<=大小)...
祝你好运!
关于c++ - 套接字上的FTP写入错误的文件和不同大小的C++，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/61378526/