dl=1 option error

[Hail-Kang]

Hi, 

Until recently, I downloaded a file using the dl=1 parameter in my C++ code.

ex) https://www.dropbox.com/{private_url}?dl=1

But now it doesn't work.

If use Python's requests module with the same URL, it will work.

And when you call another URL(not dropbox) with the corresponding C++ code, it is worked.

This is my code.

#include <iostream>
#include <Windows.h>

#ifndef DEFINE_WIN_HTTP
#define DEFINE_WIN_HTTP 1
#include <Winhttp.h>
#pragma comment (lib, "winhttp.lib")
#endif

#define BUFFER_SIZE 4096

int main()
{
	WCHAR szUrl[] = L"https://www.dropbox.com/{private_url}?dl=1";
	BYTE response[4096];

	HINTERNET      hSession, hConnect, hRequest;
	URL_COMPONENTS urlComponents;
	WCHAR          szHostName[256], szUrlPath[2048];
	DWORD          dwSize;
	DWORD          dwStatusCode;

	hSession = WinHttpOpen(L"sample", WINHTTP_ACCESS_TYPE_AUTOMATIC_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);
	if (hSession == NULL)
		return -1;

	ZeroMemory(&urlComponents, sizeof(URL_COMPONENTS));
	urlComponents.dwStructSize = sizeof(URL_COMPONENTS);
	urlComponents.lpszHostName = szHostName;
	urlComponents.dwHostNameLength = sizeof(szHostName) / sizeof(WCHAR);
	urlComponents.lpszUrlPath = szUrlPath;
	urlComponents.dwUrlPathLength = sizeof(szUrlPath) / sizeof(WCHAR);



	if (!WinHttpCrackUrl(szUrl, lstrlenW(szUrl), 0, &urlComponents)) {
		WinHttpCloseHandle(hSession);
		return -2;
	}

	hConnect = WinHttpConnect(hSession, szHostName, INTERNET_DEFAULT_PORT, 0);
	if (hConnect == NULL) {
		WinHttpCloseHandle(hSession);
		return -3;
	}

	hRequest = WinHttpOpenRequest(hConnect, L"GET", szUrlPath, NULL, WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, 0);
	if (hRequest == NULL) {
		WinHttpCloseHandle(hConnect);
		WinHttpCloseHandle(hSession);
		return -4;
	}

	if (!WinHttpSendRequest(hRequest, WINHTTP_NO_ADDITIONAL_HEADERS, 0, WINHTTP_NO_REQUEST_DATA, 0, 0, 0)) {
		WinHttpCloseHandle(hRequest);
		WinHttpCloseHandle(hConnect);
		WinHttpCloseHandle(hSession);
		return -5;
	}

	WinHttpReceiveResponse(hRequest, NULL);

	dwSize = sizeof(DWORD);
	WinHttpQueryHeaders(hRequest, WINHTTP_QUERY_STATUS_CODE | WINHTTP_QUERY_FLAG_NUMBER, WINHTTP_HEADER_NAME_BY_INDEX, &dwStatusCode, &dwSize, WINHTTP_NO_HEADER_INDEX);
	if (dwStatusCode == HTTP_STATUS_OK)
	{
		if (!WinHttpQueryDataAvailable(hRequest, &dwSize))
			printf("Error %u in WinHttpQueryDataAvailable.\n",
				GetLastError());

		ZeroMemory(response, dwSize + 1);
		WinHttpReadData(hRequest, response, sizeof(BYTE) * BUFFER_SIZE, NULL);
	}
	else {
		TCHAR szBuf[256];
		wsprintf(szBuf, TEXT("Status Code %d"), dwStatusCode);
	}

	WinHttpCloseHandle(hRequest);
	WinHttpCloseHandle(hConnect);
	WinHttpCloseHandle(hSession);

	std::string response_string = std::string((char*)response);
	std::cout << response_string;

	return 0;
}

[Greg-DB]

Can you elaborate on what you mean when you say "it doesn't work"? What unexpected error or output are you getting?