Wikipedia:Reference desk/Archives/Computing/2015 December 28

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December 28

Djvu files processing

Can we dismember a djvu file in its text, images, format in the same way as a html? If yes, what would be a good program for that?

If anyone is knowledgeable in Djvu, he could also check this bit "Why won't Google index DjVu files after all this time? – topic on PlanetDjVu". It's from 2006, I don't know whether it's still up-to-date.

--Scicurious (talk) 00:56, 28 December 2015 (UTC)

IP addresses

I've never understood IP addresses very well; the answer may be easy to find, but only if you know how to look for it, and I don't.

Some self-denominated troll just left a couple of notes at my talk page, within seconds of each other, using two different IPs: 81.158.98.166 and 86.131.23.182. How is it possible to use two completely different IP addresses within just a few seconds of each other? I can imagine someone using two separate computers (e.g. one's with a cellphone, and the other is a desktop) to accomplish this, but if you're using just one computer, is such a feat possible without using an open proxy? Nyttend (talk) 02:11, 28 December 2015 (UTC)

Without access to multiple networks, you need the right ISP to do this. Some ISPs will change your IP address every few hours. Some will change it when you reset the router. Some will reassign the same IP address to the same person for years. Others can change IP with every edit. -- zzuuzz ^(talk) 19:04, 28 December 2015 (UTC)

I agree that many things can change your IP, but don't see how an ISP can change the IP with every edit.--Denidi (talk) 20:44, 28 December 2015 (UTC)

Part of the confusing thing is that this isn't someone whose ISP changes the address with every edit; see Special:Contributions/81.158.98.166 (24 edits) and Special:Contributions/86.131.23.182 (47 edits), and the edits stopped long before the blocks were imposed. Nyttend (talk) 21:00, 28 December 2015 (UTC)

The ones which change on every edit are normally caching proxies. We used to get this really bad from AOL (see Wikipedia:AOL). You can still see some who do this (notably SingNet - see Template:SingNet, and some American schools). These IP addresses are BT, which uses several parts of its enormous ranges, on a regional basis. So while the IP ranges might look disparate, they are actually quite contained. Not having used this ISP I can't say if they're resetting the router, or whether it's an automatic part of normal operations. -- zzuuzz ^(talk) 21:22, 28 December 2015 (UTC)

You seem to be assuming it isn't someone with access to multiple systems. It's not that hard to get access to multiple IP addresses if you really want to, and are prepared to maybe spend a bit of money. You can hop around public Wi-Fi networks, buy access to proxy servers or botnets, and so on. --71.119.131.184 (talk) 23:00, 28 December 2015 (UTC)

Web Cambo Delenda Est!

I have had to reboot a 2009 Gateway NV78 which, when i uninstall the MS Video WebCam, no works until I reboots the device, at which time the driver is reinstalled and activated.

Other than shining a really bright light into the inbuilt webcam, how can I keep my pornographic webstreaming secret, to the point I need to downlod a VLC file andsend that through a secure server. I fear the Butlerian Jihad approacheth, as per Jaron Lanier, and the WaPo TechSkeps. μηδείς (talk) 06:31, 28 December 2015 (UTC)

There are subtler and harder-to-defend dangers, but this one should be easily dealt with with a tiny square of duct tape, unless I'm misunderstanding. --Trovatore (talk) 06:41, 28 December 2015 (UTC)

In fact, relying on uninstalling drivers seems a foolish method since the only way someone can be seeing your webcam without you realising is if they secretly install software which allows them to. But if they can do that, they can also re-install the drivers. Even if you normally have to reboot after installing the drivers, it would be foolish to assume an adversary interested in spying on you would definitely have to do the same. Also they could always reboot when it's unlikely you are looking (if it's a laptop probably including when you think the device is off because the screen is closed). Note even if you have open windows, including with unsaved data, it would be possible to replicate this after reboot. Potentially they could disable your monitor and fans (admitedly doing it while the device is rebooting is more difficult) so the device may seem off to you. Of course if they aren't super desperate to record right now, they could just wait until you do reboot (perhaps because an update is saying you need to). Note that checking for the presence of the drivers would likewise be unreliable since they could surely hide the presence of the drivers. Depending on the level of effort, you may be able to notice some, but it won't be that hard to make it such that you are unlikely to notice unless you look very carefully. Nil Einne (talk) 07:36, 28 December 2015 (UTC)

Just wanted to add, even if your adversary is a bored script kiddy who isn't going to do anything sophisticated, it's still a bad idea to rely on uninstalling drivers. If they have sufficient access to your computer to misuse your webcame, the most likely thing which requires little sophistication if you uninstalled drivers would be to reinstall them and if a reboot is needed either wait for a reboot, or just reboot and perhaps hope you don't notice or force a BSOD. Either way, even though you can see that the webcam in Device Manager, are you going to notice if you thought you successfully removed the drivers for good? Probably not. Perhaps any of this would be either "too hard" or "too much work", still it's since there's a far more reliable alternative, it makes much more sense to rely on that. But if you really want to go down this route, AFAIK when you disable the device it shouldn't be re-enabled unless someone does it manually. Alternatively, updating the drivers, browsing your computer, turning off show compatible devices and chosing something that definitely won't work would probably do the trick. (At least I don't think Windows Update will ever fix this case, although I'm not certain.) Nil Einne (talk) 14:20, 30 December 2015 (UTC)

Is there any place I can find an example of Kraay sort algorithm code?

Is there any place I can find an example of kraay sort algorithm code or pseudocode?200.217.39.217 (talk) 17:24, 28 December 2015 (UTC)

Are you sure it exists? Googling "kraay sort" only turns up one pseudonymous comment in this Reddit thread, which cites U.S. patent 6202068, which doesn't have the word "sort" in its claims and doesn't seem to be about sorting. -- BenRG (talk) 18:54, 28 December 2015 (UTC)

Maybe Cray Computer's Sort module, part of their Chapel (programming language) standard library? Nimur (talk) 20:36, 28 December 2015 (UTC)

Is that related to Kraay, David R., and Patrick T. Harker. "Real-time scheduling of freight railroads." in Transportation Research Part B: Methodological 29.3 (1995): 213-229.Denidi (talk) 20:40, 28 December 2015 (UTC)

Good resource comparing programming languages

What site, if any, let's you pick a set of programming languages (say C#, Java, js) and shows a comparison of them by code snippets (not just a table of features)? --3dcaddy (talk) 23:29, 28 December 2015 (UTC)

Rosetta Code -- Finlay McWalterᚠTalk 00:19, 29 December 2015 (UTC)

My problem with this one is the usability of the site. Somehow you are stuck with the "full package" of 100+ languages and can't just see the languages your are interested in.3dcaddy (talk) 00:26, 29 December 2015 (UTC)