C ++ Winsock Google搜索查询GET请求

Question

我想使用C ++中的Winsock通过GET请求在Google上进行搜索查询。

现在，响应具有脚本和样式，但没有任何实际搜索结果。最终目标是能够从Google检索到PDF的链接。

例如以编程方式进行这样的搜索查询：www.google.com/search?as_q=Computer+Networking&as_filetype=pdf

这是出于学习目的，我想坚持使用Winsock，而不是其他任何库。

#include "pch.h"

#define _WINSOCK_DEPRECATED_NO_WARNINGS

#include <WinSock2.h>
#include <WS2tcpip.h>
#pragma comment(lib, "Ws2_32.lib")
#include <string>
#include <fstream>
#include <iostream>

int error(std::string message);

static int err = 0;
static char buffer[0xFFFFFFF];

int main()
{
    std::string url = "www.google.com";
    std::string query = "Computer+Networking";

    // Store source code response here
    std::string source;

    WSAData wsaData;
    SOCKET Socket = INVALID_SOCKET;
    SOCKADDR_IN SockAddr;
    struct hostent *host;

    std::string GET = "";
    GET += "GET /search?as_q=" + query + "&as_filetype=pdf HTTP/1.1\r\n";
    GET += "Accept-Encoding: gzip, deflate, br";
    GET += "Accept-Language: en-US, en; q=0.9, nb; q=0.1";
    GET += "Cache-Control: no-cache";
    GET += "Content-Type: text/plain; charset=UTF-8";
    GET += "Host: " + url + "\r\n";
    GET += "Connection: close\r\n\r\n";

    err = WSAStartup(MAKEWORD(2, 2), &wsaData);
    if (err)
        return error("WSAStartup");

    Socket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (Socket == INVALID_SOCKET)
        return error("Invalid socket.");

    host = gethostbyname(url.c_str());

    SockAddr.sin_port = htons(80);
    SockAddr.sin_family = AF_INET;
    SockAddr.sin_addr.s_addr = *((unsigned long*)host->h_addr);

    err = connect(Socket, (SOCKADDR*)(&SockAddr), sizeof(SockAddr));
    if (err)
        return error("Connection failed.");

    send(Socket, GET.c_str(), strlen(GET.c_str()), NULL);

    int i = 0;
    int nDataLength;
    while ((nDataLength = recv(Socket, buffer, 0xFFFFFFF, NULL)) > 0)
    {
        while (buffer[i] >= 32 || buffer[i] == '\n' || buffer[i] == '\r')
        {
            source += buffer[i];
            i++;
        }
    }

    closesocket(Socket);
    WSACleanup();

    std::cout << source << std::endl;
}

int error(std::string message)
{
    std::cout << "ERROR: " << message << std::endl;
    return -1;
}