Should I use URLDownloadToFile?

Question

I am looking for the most simple way to download a file in C++ (on Windows). URLDownloadToFile sounds great and does not require me to use curl or other fat libraries that I don't need - what are the requirements for this function? Which Windows's will it run on?

Thanks!

Answer 1

http://msdn.microsoft.com/en-us/library/ms775123%28VS.85%29.aspx

The documentation is there for a reason.

E: Just glancing at the documentation, it requires a minimum of Internet Explorer 3.0 and Windows 95. Vanishingly few computers do not meet those requirements.

E: Here's a sample of how to use this function. You also need to link Urlmon.lib to compile:

#include "stdafx.h"
#include <stdio.h>
#include <tchar.h>

#include <windows.h>
#include <Urlmon.h>

int _tmain(int argc, _TCHAR* argv[])
{
    printf("URLDownloadToFile test function.\n");

    TCHAR url[] = TEXT("http://google.com");

    printf("Url: %S\n", url);

    TCHAR path[MAX_PATH];

    GetCurrentDirectory(MAX_PATH, path);

    wsprintf(path, TEXT("%s\\index.html"), path);

    printf("Path: %S\n", path);

    HRESULT res = URLDownloadToFile(NULL, url, path, 0, NULL);

    if(res == S_OK) {
        printf("Ok\n");
    } else if(res == E_OUTOFMEMORY) {
        printf("Buffer length invalid, or insufficient memory\n");
    } else if(res == INET_E_DOWNLOAD_FAILURE) {
        printf("URL is invalid\n");
    } else {
        printf("Other error: %d\n", res);
    }

    return 0;
}

Answer 2

I use this function in a WTL C++ app and have yet to come across any PC that didn't support it (the app in question has been installed on thousands of clients, a mix of Windows 2000, XP, Vista and Windows 7). There are no .NET dependencies either BTW - it's buried in an old Internet Explorer Win32 DLL. It is very simple to use, accepts any URL and even a normal DOS-style filename will work (we sometimes use it to fetch files from a network share.)