C++HTTP GET请求问题

C++ HTTP GET request problems?

本文关键字：问题 请求 GET C++HTTP      更新时间：2023-10-16

我编写了一个程序，它将tcp请求发送到命令行中指定的web地址，并打印响应。当我把这个请求发送到www.google.co.uk（或任何网站）时，我什么都没有得到：（

有人能告诉我我做错了什么，以及向谷歌发出正确的GET请求应该是什么样子吗。这是代码。。。

#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: %dn", 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: %dn", 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(): %ldn", 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/1.1rn";
char recvbuf[DEFAULT_BUFLEN];
//Send an initial buffer
iResult = send(ConnectSocket, sendbuf, (int)strlen(sendbuf), 0);
if(iResult == SOCKET_ERROR){
    printf("send failed: %dn", WSAGetLastError());
    closesocket(ConnectSocket);
    WSACleanup();
    return 1;
}
printf("Bytes Sent: %ldn", 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: %dn", WSAGetLastError());
    closesocket(ConnectSocket);
    WSACleanup();
    return 1;
}
do {
    iResult = recv(ConnectSocket, recvbuf, recvbuflen, 0);
    if(iResult > 0){
        printf("Bytes received: %dn", iResult);
        printf(recvbuf);
        printf("nn");
    } else if(iResult == 0){
        printf("Connection closedn");
    } else {
        printf("recv failed: %dn", WSAGetLastError());
    }
} while(iResult > 0);
//cleanup
closesocket(ConnectSocket);
WSACleanup();
return 0;
 }

提前谢谢。

一个可能的原因是服务器在发送响应之前需要更多的数据。

char *sendbuf = "GET /index.html HTTP/1.1rn";

这应该是

char *sendbuf = "GET /index.html HTTP/1.1rnrn";

以便告诉服务器不要期望更多的HTTP标头（每个标头后面跟着一个rn，然后添加一个额外的rn来结束请求）。

基本上，您的HTTP请求是不完整的。必须至少再提供一个标头（Host）。请注意，无论如何，服务器都可能（错误地）接受不完整的请求。如果您想简单启动，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）。

相关文章：