C++ HTTP GET请求问题？

我写了一个程序，它向命令行中指定的Web地址发送一个tcp请求并打印响应。当我发送这个请求到www.google.co.uk（或任何网站）时，我没有得到任何回应:(C++ HTTP GET请求问题？

有人可以告诉我我做错了什么，以及什么正确的GET请求谷歌应该看看等等。下面的代码...

#include <WinSock2.h> 
#include <WS2tcpip.h> 
#include <stdio.h> 

#pragma comment(lib, "Ws2_32.lib") 

int main(int argc, char *argv[]){ 

WSADATA wsaData; 
int iResult; 

//Initialize Winsock 
iResult = WSAStartup(MAKEWORD(2,2), &wsaData); 
if(iResult != 0){ 
    printf("WSAStartup failed: %d\n", iResult); 
    return 1; 
} 

struct addrinfo *result = NULL, 
       *ptr = NULL, 
       hints; 

ZeroMemory(&hints, sizeof(hints)); 
hints.ai_family = AF_INET; 
hints.ai_socktype = SOCK_STREAM; 
hints.ai_protocol = IPPROTO_TCP; 

#define DEFAULT_PORT "80" 

//Resolve the server address and port 
iResult = getaddrinfo(argv[1], DEFAULT_PORT, &hints, &result); 
if(iResult != 0){ 
    printf("getaddrinfo failed: %d\n", iResult); 
    WSACleanup(); 
    return 1; 
} 

SOCKET ConnectSocket = INVALID_SOCKET; 

//Attempt to connect to the first address returned by 
//the call to getaddrinfo 
ptr = result; 

//Create a SOCKET for connecting to server 
ConnectSocket = socket(ptr->ai_family, ptr->ai_socktype, 
    ptr->ai_protocol); 

if(ConnectSocket == INVALID_SOCKET){ 
    printf("Error at socket(): %ld\n", WSAGetLastError()); 
    freeaddrinfo(result); 
    WSACleanup(); 
    return 1; 
} 

//Connect to server 
iResult = connect(ConnectSocket, ptr->ai_addr, (int)ptr->ai_addrlen); 
if(iResult == SOCKET_ERROR){ 
    closesocket(ConnectSocket); 
    ConnectSocket = INVALID_SOCKET; 
} 

//Should really try the next address returned by getaddrinfo 
//if the connect call failed 
//But for this simple example we just free the resources 
//returned by getaddrinfo and print an error message 

freeaddrinfo(result); 

if(ConnectSocket == INVALID_SOCKET){ 
    printf("Unable to connect to server!\n"); 
    WSACleanup(); 
    return 1; 
} 

#define DEFAULT_BUFLEN 512 

int recvbuflen = DEFAULT_BUFLEN; 

char *sendbuf = "GET /index.html HTTP/1.1\r\n"; 
char recvbuf[DEFAULT_BUFLEN]; 

//Send an initial buffer 
iResult = send(ConnectSocket, sendbuf, (int)strlen(sendbuf), 0); 
if(iResult == SOCKET_ERROR){ 
    printf("send failed: %d\n", WSAGetLastError()); 
    closesocket(ConnectSocket); 
    WSACleanup(); 
    return 1; 
} 

printf("Bytes Sent: %ld\n", iResult); 

//shutdown the connection for sending since no more data will be sent 
//the client can still use the ConenctSocket for receiving data 
iResult = shutdown(ConnectSocket, SD_SEND); 
if(iResult == SOCKET_ERROR){ 
    printf("shutdown failed: %d\n", WSAGetLastError()); 
    closesocket(ConnectSocket); 
    WSACleanup(); 
    return 1; 
} 

do { 
    iResult = recv(ConnectSocket, recvbuf, recvbuflen, 0); 
    if(iResult > 0){ 
     printf("Bytes received: %d\n", iResult); 
     printf(recvbuf); 
     printf("\n\n"); 
    } else if(iResult == 0){ 
     printf("Connection closed\n"); 
    } else { 
     printf("recv failed: %d\n", WSAGetLastError()); 
    } 
} while(iResult > 0); 

//cleanup 
closesocket(ConnectSocket); 
WSACleanup(); 

return 0; 
}

在此先感谢。

来源

2012-07-10 brnby

您是否尝试过没有向页面发送请求？我只是想知道，因为你怎么知道索引页是'index.html'还是'index.html'甚至'home.html'等，等等？所以我会尝试像GET GET/1.1这样的请求。为什么在收到答案之前关闭连接？ – 2012-07-10 16:15:56

“我什么都不回来”是什么意思？你收到0字节，你的程序冻结或突然结束，没有打印任何东西！？ – 2012-07-10 16:16:21

@ViteFalcon：没关系。如果URL无效，那么服务器无论如何都会发送正确的HTTP响应（重定向，未找到页面等） – 2012-07-10 16:17:16

一个可能的原因是服务器发送响应之前，希望有更多的数据。

char *sendbuf = "GET /index.html HTTP/1.1\r\n";

ŧ他应该proabably是

char *sendbuf = "GET /index.html HTTP/1.1\r\n\r\n";

，这样你告诉服务器不要期待更多的HTTP报头（每头后面是\r\n再额外\r\n添加到结束的请求）。

基本上，您的HTTP请求是不完整的。至少还有一个标题（Host）必须提供。请注意，服务器可能（不正确）接受和不完整的请求。如果您想简单地开始，请复制浏览器发送的请求（例如，打开Web调试器并查看传出的网络请求）。

来源

2012-07-10 16:19:32

它预计不止于此。一个HTTP 1.1请求也需要包含一个'Host'头文件，例如：'char * sendbug =“GET /index.html HTTP/1.1 \ r \ n主机：TheServerHostNameHere \ r \ n \ r \ n”;' – 2012-07-10 18:02:27

@RemyLebeau：谢谢。我补充说，答案。 – 2012-07-10 21:20:13

C++ HTTP GET请求问题？

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