在Windows套接字上fprintf中使用

问题描述

我想在Windows上的插座上使用fprintf中。许多在线的例子是。等效code为Windows是什么，我问在这里。

I'm trying to use fprintf on a socket on Windows. Many of the online examples are UNIX examples. The equivalent code for Windows is what I'm asking about here.

最后，我想做到这一点：

Ultimately, I'd like to do this:

fprintf(file_handle_to_socket, "hello world\r\n");

我不希望使用WriteFile的，snprintf的或其他任何东西。只是fprintf中（）。

I do not want to use WriteFile, snprintf or anything else. Just fprintf().

伪code或多或少显示的步骤将是有益的。

Pseudocode that more or less shows the steps would be helpful.

下面是我到目前为止有：

Here is what I have so far:

unsigned short port = enter_port;

int result = 0;
WSADATA wsaData;
result = WSAStartup(MAKEWORD(2, 2), &wsaData);

struct sockaddr_in local;
memset(&local, 0, sizeof(struct sockaddr_in));

local.sin_port = htons(port);
local.sin_family = AF_INET;
local.sin_addr.s_addr = htonl(INADDR_ANY);

int sock = socket(AF_INET, SOCK_STREAM, 0);
if(sock == INVALID_SOCKET)
{
    fprintf(stdout,"invalid socket: error code %d\n", WSAGetLastError());
}

result = bind(sock, (struct sockaddr*)&local, sizeof(struct sockaddr_in));
if(result == SOCKET_ERROR)
{
    fprintf(stdout,"bind() failed: error code %d\n", WSAGetLastError());
}

result = listen(sock, 5);

struct sockaddr peer;
memset(&peer, 0, sizeof(struct sockaddr));

SOCKET client = 0;
int size = sizeof(struct sockaddr);
client = accept(sock, &peer, &size);

int OSFileHandle = _open_osfhandle(client, _O_APPEND);
FILE * file_handle_to_socket = fdopen(OSFileHandle, "w+");

fprintf(file_handle_to_socket, "Hello World\r\n");

// hoping this helps -- it doesn't
fflush(file_handle_to_socket);

fclose(file_handle_to_socket);
closesocket(client);

// this throws an exception
WSACleanup();

当我运行这个，没事出来在另一端（使用腻子），我在WSACleanup得到一个异常（）;在WSACleanup唯一的例外是无效的句柄指定。

When I run this, nothing comes out on the other end (using putty) and I get an exception at WSACleanup(); The exception at WSACleanup is An invalid handle was specified.

更新我发现通过的的。
如果我更换：

UPDATE I found a strong lead by reading this post more closely.If I replace:

fprintf(file_handle_to_socket, "Hello World\r\n");

与

fprintfsock(client, "Hello World\r\n");

它的工作原理。

这仍然不是一个完整的回答我的问题虽然。我期待直接使用fprintf中（）。

It's still not a complete answer to my question though. I'm looking to use fprintf() directly.

推荐答案

一个套接字不是一个文件句柄，所以你不能使用 _open_osfhandle（）来包装它。这就是为什么 fprintf中（）不工作。 fprintfsock（）是专门设计直接与插座的工作。它仅仅是将数据格式转换成一个本地缓冲区的包装，然后使用套接字API 发送（）函数来发送。如果你真的想使用 fprintf中（）用插座，你将不得不和#undef fprintf中然后 fprintf中的#define（）如果您使用的是编译器重新映射它 fprintfsock（）（将只工作了支持复杂的宏）。否则，只要使用 fprintfsock（）直接

A socket is not a file handle, so you cannot use _open_osfhandle() to wrap it. That is why fprintf() is not working. fprintfsock() is specifically designed to work with a socket directly. It is merely a wrapper that formats the data into a local buffer and then uses the socket API send() function to send it. If you really want to use fprintf() with a socket, you will have to #undef fprintf and then #define fprintf() to re-map it to fprintfsock() (which will only work if you are using a compiler that supports variadic macros). Otherwise, just use fprintfsock() directly.

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