FTP issue with small files


I'm using Dopus under WinXP SP2 and experiencing an odd problem with FTP transfers. When I FTP upload to various sites everything works fine but when I FTP download small files (under a 1K for example) the resulting files end up being 0 bytes.

I've tried transfer by automatic, binary and ASCII with no luck. The files are ASCII text config files.

I am using ftp hosts running *nix variations but other FTP clients (LeapFTP) are having no issue with the files.

Anybody else experience this problem with Dopus?


Scott Watson

I've seen this occasionally in the past as well. Only seems to happen with small files. Might depend on the speed of the site or type of server at the other end but I'm not sure. Usually it works fine for me but I have seen what you describe.

I've seen it once or twice and chalked it up to a random occurence of my cosmic string theory (actually, a theory borrowed from my friend Mark).

I've seen this many many times, almost each time i use dopus to transfer a web site. And yes it happens with small files, i would say under 1k

Maybe this is a bug ?

I confirm the problem.

I already reported it to Greg and created a thread here.

I have tried several configurations (different versions of Windows, totally different networks,...) and I have yet to find a configuration where it does not happen.

This is really frustrating as a lot of files are below or around 1kb when working on websites...

I may be wrong but it seems this problem is not taken seriously by DOpus' authors... I think this should be corrected as soon as possible: having to run a separate FTP client just to download some files is really really annoying when you could do that with DOpus :frowning:


Integrated FTP was one of those extra features that helped me make the decision to buy Dopus in the first place. Most of my FTP use is for websites and programming, so the bug stops me cold.

I hope they sort it out soon.

Well I've just looked into this again trying it on 6 different servers including two local servers and localhost. And, I can't see any issues nor problems with small files or 50-100 bytes etc.

Maybe it's just specific servers, or firewalls or Zone Alarm or some other strange interaction, but neither Jon nor I can reproduce it.

I'm not saying it doesn't happen and I do believe that some people see the issue but I can't find any specific problems in Opus itself. So, if you can repeat this please email me directly with details and I'll be happy to try to repeat what you are seeing.


Just to let you know, i did not see the problem with an other ftp software, i use cuteftp.

it only happens with Dopus

however, if i resend the files which has not been sent, it usually works, maybe you could implement some kind of checking at some point, that is resend files when they are 0 bytes ?


PS: i have no zone alarm, just the regular windows xp sp2 firewall and a netgear rooter, same happens on a different network with a linksys router.

The small-files FTP issue should be fixed with the Opus update. I was able to reproduce the problem before but no longer can with the update.

I'll update and let you know if I have any problems.

Thanks for your help.

Scott Watson

Yes this is fixed in the 8.2.1 version. Nudel was able to do some testing for me on debug versions so even though we could never repeat it here I was able to find the problem.

Actually it was a good hunt and ended up a 'Beautiful Theory' issue. It only took one line of code to resolve it!

Unfortunately the problem was only evident on fast connections with certain servers when the connection data was opened, data sent in one packet then connection closed before the control connection was notified that there was a connection! With the impressive Slowband speeds that Telstra permit Australians to have here, I was never able to get a fast enough connection to a site to actually see the problem! And my local servers are either Serv-U which behaves properly in such regards to threading of the control and data connections, or Linux servers which were slow enough to not show the issue either.

So, it's fixed. 100% guarantee!

"Yay!" I thought.

I reported this issue an aeon ago, so it was great to hear the new version had apparently fixed it. But alas I am still experiencing problems with zero (0) byte files.

Why am I uploading zero byte files you may ask? Well, many projects I upload come originally from a CVS repository and still have the CVS folder and files in EACH subfolder. Some of these files can be zero byte files, and DOpus sometimes (not always) stalls completely on them. I can't Skip or Abort, but either have to kill the process or wait for a 900 second timeout (this must be a server timeout because I can't find it anywhere in the DOpus prefs).

I know I'm just being lazy by not culling the CVS folders before upload and that there's probably some way to let DOpus to ignore these during FTP, but DOpus still shouldn't be choking on them.


Your problem is likely to be a different issue. The "small files issue" fixed in the latest version was where small (but not empty) files would be downloaded as empty over fast connections from some FTP servers.

Have you checked that the problem you're seeing with empty files (that are meant to be empty) stalling doesn't also happen if you either use Opus to upload to a different FTP server or use a different FTP clien to upload to the same server? Hopefully GPSoft can look at the problem either way, but while we wait for Australia to wake up it's worth looking into whether it's Opus, the FTP server or some combination of the two. That way it'll be easier to track down.

The problem fixed in was to do with downloading small files. Nothing involving uploading from your local system to ftp would have been affected - so if there are problems there as well it's something different.


There's no issue in uploading zero byte files as far a I am aware and I do this quite often. Would you please talk to me directly (by direct email) on this and give me some specific details so I can test exactly what you are seeing.