URLDownloadToFile

[Gary Beene]

For solutions to downloading files, I've used TCP statements so I could monitor download progress and I've used URLDownloadTo File for simpler code.

I've yet to have a problem with URLDownloadToFile, other than needing to clear the cache, and wondered if anyone knows a reason why it's not a completely acceptable approach for downloading files?

[Michael Mattias]

.. if anyone knows a reason why [URLDownLoadtoFile is] not a completely acceptable approach for downloading files?

Not acceptable to whom?

(BTW: you don't need to clear the cache, unless you are trying to do some kind of quasi-realtime monitoring, in which case URLDownloadToFile is, IMO, a really inferior design)


MCM

[José Roca]

> For solutions to downloading files, I've used TCP statements so I could monitor download progress and I've used URLDownloadTo File for simpler code.

You can also monitor download progress with UrlDownloadToFile.

[Gary Beene]

Hi MCM,
To me, of course!

But, more seriously, my question is whether there any serious technical problems known to exist with the API, work arounds needed to get useful/repeatable results, applications in which the API is known to give problems, ... that kind of stuff. If someone has made a choice NOT to use the API, I'm interested in hearing why.

[Gary Beene]

Hey Jose!

Thanks for the input, but neither I, nor Google, seem to have heard of that API...

Showing results for UrlDownloadToFile
No results found for UstlDownloadToFile

Can you guide me to some information on the API?

[Pierre Bellisle]

Old fashion, but the idea is there... URLDownloadToFile

[José Roca]

Hey Jose!

Thanks for the input, but neither I, nor Google, seem to have heard of that API... ?



Can you guide me to some information on the API?

Sorry, it was a typo. I mean UrlDownloadToFile,

BTW we already have discussed it. See: https://forum.powerbasic.com/forum/u...dtofile-vs-tcp

Also see my WinHttpRequest examples, e.g.

https://forum.powerbasic.com/forum/jose-s-corner/source-code-ab/51694-winhhtp-com-examples?p=612015#post612015

https://forum.powerbasic.com/forum/jose-s-corner/source-code-ab/51694-winhhtp-com-examples?p=612014#post612014

[Mike Doty]

(BTW: you don't need to clear the cache, unless you are trying to do some kind of quasi-realtime monitoring, in which case URLDownloadToFile is, IMO, a really inferior design)
MCM

MCM.
Why are you telling people not to clear the cache before downloading?
If a file exists in cache the download will continue to use the old copy in cache.

hr =DeleteURLCacheEntry(sURL + $NUL) '1 = success clear the cache before download

GB,

I've yet to have a problem with URLDownloadToFile, other than needing to clear the cache, and wondered if anyone knows a reason why it's not a completely acceptable approach for downloading files?

1. It doesn't work with https. wrong, it is working now. had trouble with it years ago. thanks bob carver.
2. Not a secure channel
3. Data can be intercepted and read or changed
4. Data is not verified.
5. Data may not be encrypted

I've posted code using Jose's code with progress.
There is also code somewhere to download https using TCP, but can't find it.
Still doubt if it is using a secure channel.

[Michael Mattias]

Why are you telling people not to clear the cache before downloading?

I did not say not to do it; I said it was unnecessary UNLESS <application condition>.

What you have described is multiple downloads of the same filename, which pretty much equals <application condition>.

But going back to my first point: I did NOT suggest not clearing the cache. Please do not misquote me like this.

MCM

[Mike Doty]

you don't need to clear the cache, unless you are trying to do some kind of quasi-realtime monitoring,

This is inaccurate

[Bob Carver]

1. It doesn't work with https

This is also inaccurate

[Mike Doty]

Bob,
You are right. It is definitely working.with Windows 10.
Not sure what was going wrong a couple of years ago.
Updated my remarks in post #8.
Thank you!

#INCLUDE "win32api.inc"
#INCLUDE "wininet.inc"
FUNCTION PBMAIN()
 LOCAL errcode    AS LONG
 LOCAL zurl       AS ASCIIZ * 512
 LOCAL zlocalfile AS ASCIIZ * 512
 zurl       = "https://www.dotysoftware.com/junk.exe"  '200,000,000 bytes
 mkdir "c:\mytest"
 errclear
 zlocalfile = "\mytest\junk.exe"
 errcode = DeleteURLCacheEntry(zurl) '1=success, 0=failed
 errcode  = urlDownloadToFile(BYVAL 0,zurl,zlocalfile,0,0)
 IF errcode = 0 THEN ? "Download ok" ELSE ? "Download error" + STR$(errcode)
END FUNCTION

[Gary Beene]

Hey Mike,
Aren't your 2-5 comments a function of whether the site has an SSL certificate? If it does, then the 2-5 issues you discuss do not apply, do they?

MCM,
Thanks for this opinion...

....a really inferior design)

.... but could you clarify why you have the opinion?

[Mike Doty]

Depends if connection is secure.
A browser will use TLS, but does urlDownloadToFile make a secure connection?

[Gary Beene]

Mike,
That's a good question. I'll contact my server folks and see what they know about it.

[Mike Doty]

When I look at 3rd party controls they always seem to have a parameter like bUseTls

https://www.example-code.com/vb6/socket_transfer_file.asp

[Mike Doty]

In post#8, I said urlDownloadToFile stopped working when using https.
That should have been tcp stopped working with https: Thanks to Bob Carver for reporting my error.
Somebody posted code to work with TCP (which I need to find), but I switched to Jose Roca code a couple of years ago with progress bar.

Gary,
About urlDownloadToFile automatically making a secure connection (which I doubt.)

Mike,

That's a good question. I'll contact my server folks and see what they know about it.

[Dale Yarker]

HTTPS uses TCP

HTTP uses TCP

FTP uses TCP

Lots of protocols use TCP. Your problem is not with TCP, it is the security that HTTPS adds that HTTP does not use.

TCP and UDP are different things at the same level, and they use IP.

IP uses ethernet.

Ethernet can use CAT-5, coax, optical fiber, WiFi, etc, etc.

What you are looking for is the security code (as in PB source code).

TCP never stopped working with HTTPS, and is still needed, you just don't have enough code.

added: If you use API or 3rd party DLL for HTTPS you may not see code for TCP OPEN, TCP SEND, etc, but the TCP is there. It is just that you don't use PB's TCP statements. If you find just security code then you do use PB's TCP statements.

[Mike Doty]

Does urlDownloadToFile offer any certificate security?

https://forum.powerbasic.com/forum/u...-ssl-supported

.

If anyone has security code for secure TLS connections, please post a link.
Here is some c++ code using schannel client/server with links in the source code.
https://www.codeproject.com/Articles...erver-With-SSL

urlDownloadToFile is definitely fast as Patrice says below.

[Patrice Terrier]

URLDownloadToFile is very reliable and fast, i am using it in several of my 64-bit applications.

This is what i am using to retrieve in real time movie informations from TMDB, to display this




SDK example to get a movie poster

[FONT=Consolas][SIZE=10px][COLOR=#008000][FONT=Consolas][SIZE=10px][COLOR=#008000][FONT=Consolas][SIZE=10px][COLOR=#008000]// Get poster[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT]
[FONT=Consolas][SIZE=10px][COLOR=#0000FF][FONT=Consolas][SIZE=10px][COLOR=#0000FF][FONT=Consolas][SIZE=10px][COLOR=#0000FF]long[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px] TMD_GetPoster([/SIZE][/FONT][/SIZE][/FONT][FONT=Consolas][SIZE=10px][COLOR=#6F008A][FONT=Consolas][SIZE=10px][COLOR=#6F008A][FONT=Consolas][SIZE=10px][COLOR=#6F008A]IN[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][COLOR=#2B91AF][FONT=Consolas][SIZE=10px][COLOR=#2B91AF][FONT=Consolas][SIZE=10px][COLOR=#2B91AF]WCHAR[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px]* [/SIZE][/FONT][/SIZE][/FONT][FONT=Consolas][SIZE=10px][COLOR=#808080][FONT=Consolas][SIZE=10px][COLOR=#808080][FONT=Consolas][SIZE=10px][COLOR=#808080]UsePath[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px]) {[/SIZE][/FONT][/SIZE][/FONT]
[FONT=Consolas][SIZE=10px][COLOR=#0000FF][FONT=Consolas][SIZE=10px][COLOR=#0000FF][FONT=Consolas][SIZE=10px][COLOR=#0000FF]long[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px] nRet = 0;[/SIZE][/FONT][/SIZE][/FONT]
[FONT=Consolas][SIZE=10px][COLOR=#2B91AF][FONT=Consolas][SIZE=10px][COLOR=#2B91AF][FONT=Consolas][SIZE=10px][COLOR=#2B91AF]WCHAR[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px] zURL[[/SIZE][/FONT][/SIZE][/FONT][FONT=Consolas][SIZE=10px][COLOR=#6F008A][FONT=Consolas][SIZE=10px][COLOR=#6F008A][FONT=Consolas][SIZE=10px][COLOR=#6F008A]MAX_PATH[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px]]; ClearMemory(zURL, [/SIZE][/FONT][/SIZE][/FONT][FONT=Consolas][SIZE=10px][COLOR=#0000FF][FONT=Consolas][SIZE=10px][COLOR=#0000FF][FONT=Consolas][SIZE=10px][COLOR=#0000FF]sizeof[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px](zURL));[/SIZE][/FONT][/SIZE][/FONT]
[FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px]Path_Combine(zURL, [/SIZE][/FONT][/SIZE][/FONT][FONT=Consolas][SIZE=10px][COLOR=#A31515][FONT=Consolas][SIZE=10px][COLOR=#A31515][FONT=Consolas][SIZE=10px][COLOR=#A31515]L"https://image.tmdb.org/t/p/w500/"[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px], gM.poster_path);[/SIZE][/FONT][/SIZE][/FONT]
[FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px]Path_Combine(gTMD.poster, [/SIZE][/FONT][/SIZE][/FONT][FONT=Consolas][SIZE=10px][COLOR=#808080][FONT=Consolas][SIZE=10px][COLOR=#808080][FONT=Consolas][SIZE=10px][COLOR=#808080]UsePath[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px], [/SIZE][/FONT][/SIZE][/FONT][FONT=Consolas][SIZE=10px][COLOR=#A31515][FONT=Consolas][SIZE=10px][COLOR=#A31515][FONT=Consolas][SIZE=10px][COLOR=#A31515]L"TMD_poster.jpg"[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px]);[/SIZE][/FONT][/SIZE][/FONT]
[FONT=Consolas][SIZE=10px][COLOR=#0000FF][FONT=Consolas][SIZE=10px][COLOR=#0000FF][FONT=Consolas][SIZE=10px][COLOR=#0000FF]if[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px] ([/SIZE][/FONT][/SIZE][/FONT][FONT=Consolas][SIZE=10px][COLOR=#6F008A][FONT=Consolas][SIZE=10px][COLOR=#6F008A][FONT=Consolas][SIZE=10px][COLOR=#6F008A]URLDownloadToFile[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px]([/SIZE][/FONT][/SIZE][/FONT][FONT=Consolas][SIZE=10px][COLOR=#6F008A][FONT=Consolas][SIZE=10px][COLOR=#6F008A][FONT=Consolas][SIZE=10px][COLOR=#6F008A]NULL[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px], zURL, gTMD.poster, 0, [/SIZE][/FONT][/SIZE][/FONT][FONT=Consolas][SIZE=10px][COLOR=#6F008A][FONT=Consolas][SIZE=10px][COLOR=#6F008A][FONT=Consolas][SIZE=10px][COLOR=#6F008A]NULL[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px]) == [/SIZE][/FONT][/SIZE][/FONT][FONT=Consolas][SIZE=10px][COLOR=#6F008A][FONT=Consolas][SIZE=10px][COLOR=#6F008A][FONT=Consolas][SIZE=10px][COLOR=#6F008A]S_OK[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px]) {[/SIZE][/FONT][/SIZE][/FONT]
[FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px]   nRet = -1;[/SIZE][/FONT][/SIZE][/FONT]
[FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px]} [/SIZE][/FONT][/SIZE][/FONT][FONT=Consolas][SIZE=10px][COLOR=#0000FF][FONT=Consolas][SIZE=10px][COLOR=#0000FF][FONT=Consolas][SIZE=10px][COLOR=#0000FF]else[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px] {[/SIZE][/FONT][/SIZE][/FONT]
[FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px]   ClearMemory(gTMD.poster, [/SIZE][/FONT][/SIZE][/FONT][FONT=Consolas][SIZE=10px][COLOR=#0000FF][FONT=Consolas][SIZE=10px][COLOR=#0000FF][FONT=Consolas][SIZE=10px][COLOR=#0000FF]sizeof[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px](gTMD.poster));[/SIZE][/FONT][/SIZE][/FONT]
[FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px]}[/SIZE][/FONT][/SIZE][/FONT]
[FONT=Consolas][SIZE=10px][COLOR=#0000FF][FONT=Consolas][SIZE=10px][COLOR=#0000FF][FONT=Consolas][SIZE=10px][COLOR=#0000FF]return[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px] nRet;[/SIZE][/FONT][/SIZE][/FONT]
[FONT=Consolas][SIZE=10px][FONT=Consolas][SIZE=10px]}[/SIZE][/FONT][/SIZE][/FONT]