Wikipedia:Reference desk/Archives/Computing/2007 May 29

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May 29[edit]

Blender Fluid Simulation Problem[edit]

I have a scene set up in Blender (Intel; Mac OS X) where water pours into a dish. If i turn the "end" value of the simulation to anything bigger that the default 30 and click bake, it starts baking from frame "-1" and then freezes. Can anyone explain why, and give a solution?-- 00:16, 29 May 2007 (UTC)

bandwidth in gaming[edit]

I think I must be pretty close to (or slightly over) 100GB of downloads alone this month. I just read Comcast#High_Speed_Internet_Service which scares me- my dad depends on our internet service for a lot of the work that he does. I'm trying to minimize my bandwidth consumption until the end of the month, and it occured to me that I have no idea how much bandwidth online gaming uses? If I play Counter-Strike: Source for 1-2 hours on a fairly full (40 man) server, how much actual data is downloaded? I play 1-2 hours basically every day, so am I in any danger of going over the "limit"? --frotht 00:46, 29 May 2007 (UTC)

It will depend on the game. Obviously older games won't try to go over 56k, newer games might go higher, I think some can easily scrape 1MB+/500k at a time. I'm sure you'll be fine, that policy is more there for comcast to get rid of people who are using them as a server than it is their regular customers. -- Phoeba WrightOBJECTION! 01:11, 29 May 2007 (UTC)

My internet is currently cappped to 64kb until the end of the month and I can still play CS Source with voice and everything with NO lag and about 5ms ping on my ISPs server. 100GB is A LOT of data for one month no matter how you put it, that would be regarded as extreme use on any ISPs plan. I'm on an enthusiast plan and I'm allowed to use 12GB in a month before I get slowed, my house mate and I played about 5 hours of WoW every day for a month with team speak and all and we used up about 1GB, you would use a fraction of a GB in a month playing 1 - 2 hours of CS a day, it would be NOTHING compared to 100GB. Vespine 02:41, 29 May 2007 (UTC)
OK so I guess I'll just lay off the bittorrent for awhile and won't worry about it thanks. --frotht 03:33, 29 May 2007 (UTC)
And I don't consider 100GB a lot at all; how is downloading at 50KB/s for a week (30 gigs- the star trek TNG series in low def) any worse for network health than downloading at 50KB/s for a month (120 gigs- a dozen movies in high def and half a dozen modern games)? --frotht 03:37, 29 May 2007 (UTC)
Come on, don't kid your self, of course it is a lot of data, how many people download more then 100GB in a month? (and not jsut the very 1st month they get their unlimited net account) I guarantee it is less then 1% of all internet users. I have almost a terabyte of storage at home, i know of course it is easy to fill 100GB with movies and games, but I also know it is a lot to download in one month. Vespine
It is a lot, but it's not as much as you're making it out to be, especially considering all of the peer-to-peer downloads flying around, and the instantaneous bandwidth available on modern ISPs. The limit for my ISP's standard plan is 60GB/month, and I know at least one or two people who have hit that cap. -- Consumed Crustacean (talk) 05:58, 29 May 2007 (UTC)
I don't think you will actually hit 100gb unless you are downloading massive amounts of stuff. I play WOW and with a whole bunch of addons gathering data from the server, I rarely was pushing 6kb/sec.--GTPoompt 17:38, 29 May 2007 (UTC)
A few of examples of bandwidth consumption:
  1. 100 hours of VOIP calling: 2.8 GB.
  2. Pandora radio playing eight hours a day for a month: 13 GB.
  3. Second Life on a fast connection with a great deal of movement from region to region: 1 GB for every four hours of play.
  4. 20 pirated DVDs, re-encoded for single-layer recording: 100 GB.
  5. 12 hours of streaming ATSC digital television: 100 GB.
--Carnildo 00:01, 30 May 2007 (UTC)
SL is a gig per four hours?! Holy crap! I can't even download that fast direct connection http! --frotht 02:52, 30 May 2007 (UTC)
Really? That's 250MB/Hr, which comes out to be around 100kbps, which isn't too bad. -- Phoeba WrightOBJECTION! 17:32, 30 May 2007 (UTC)
The numbers for SL are assuming a fast connection and a lot of movement. If you're just sitting in one place, you can almost play over dialup. --Carnildo 23:17, 30 May 2007 (UTC)
I'm surprised that Pandora doesn't consume more bandwidth, especially if you play it every day for a month. Incidentally, where did you get those numbers? Is that your own investigation, or is there an article or something? Ohh, and by the way, you guys are suckers, I'm sitting on a 24 mbit connection with unlimited downloads for ~$30/month. I just checked my Azureus statistics, and I'm pushing a terabyte in downloads over the last 3 months. --Oskar 11:16, 30 May 2007 (UTC)
For the most part, I calculated the numbers based on data in the relevant articles. The SL numbers are based on measurements I did. Pandora is 128kbps mp3, which is only 16 kilobytes per second of music. --Carnildo 23:17, 30 May 2007 (UTC)
You can also use NetLimiter or similar program for a month and see for yourself how much each program/game uses per month. For this use, a freeware Monitor version would be enough. Thats what I use to track my own internet consumption (76GB last month, on an unmetered 768kb connection, utorrent working 24/7). Shinhan 10:26, 2 June 2007 (UTC)

Bare linux kernel[edit]

What would the linux kernel, with no modifications, do by itself? Would it just start a DOS/Basic like environment? Or would it refuse to boot? Or would it be incapable of booting? I don't really need to know this, i'm just curious -- Phoeba WrightOBJECTION! 01:08, 29 May 2007 (UTC)

If you set up the bootloader correctly, it'd start, detect hardware &/c, then complain that it can't find init, then halt. Go learn yourself up on the 'nix bootup sequence.
If there's no filesystem for it to use as the root FS, it says:
Kernel panic - not syncing: VFS: Unable to mount root fs on
...followed by some internal name for the device it tried to use, for example a hard disk partition. Kernel panic means it didn't know what to do, so it gave up, and not syncing means it's not writing any data to any storage devices for fear of overwriting important data. If it does have a filesystem to use, but there's no executable file to run as the first user-space program (traditionally /sbin/init), it says:
Kernel panic - not syncing: No init found. Try passing init= option to kernel.Keenan Pepper 15:19, 29 May 2007 (UTC)
The "dos"-like environment is called a shell (computing) and is not usually considered a part of the kernel. In fact it is considered a "shell" around the kernel. So, if you did not have a shell executable installed, you could never get even as far as a command prompt. Nimur 19:27, 3 June 2007 (UTC)

Free text file compare software.[edit]

I'll try to be brief, I have 4 text files 31kb in size which are extracts from the registry of a print server, pertaining to the driver settings on 4 different print queues. 2 printers are doing what they are supposed to and 2 are not behaving correctly under a very specific condition.

I need a piece of windows software that can easily (and freely) compare 2 txt files, to first find everything that is the same on the 2 that work and then the 2 that don't, and then try to find a difference between those two. I've tried a couple of "shareware" programs but they have had save and size limitations and I have not been able to do what I need. I'm sure there must be a free tool that does exactly what I need easily.

If anyone has any more ideas I'm open to suggestions, but please don't ask me to describe the problem, trust me, all other avenues have been exhausted including vendor support… Thanks:) Vespine 02:35, 29 May 2007 (UTC)

One thing you might try, since it is free and easy: create a page in your userspace with the contents of one text file (i.e. at User:Vespine/Test). Save. Then edit the page again and paste the second text file over it. Save. Then go into the "History" tab and compare the two. Might not work well, or it might work perfectly — worth a shot, given how easy it is. -- 04:36, 29 May 2007 (UTC)
Yes! Definitely worth a try, but unfortunately even when I try to paste all 4 files the same they haven't formatted exactly the same , because of all the spaces and strange characters> I really like the idea of using wiki to solve this, since I love wiki so much, but unfortunately I think I still need a piece of software to do this. Vespine 05:08, 29 May 2007 (UTC)
In a Windows Command Prompt, you can use the fc command to show the differences between two files, which might solve part of your problem. Basic usage is fc file1 file2. Type fc /? for help. --Bavi H 06:48, 29 May 2007 (UTC)
UltraEdit has a powerful text file compare utility. We use it routinely to compare lists such as database users. Sandman30s 11:07, 29 May 2007 (UTC)
There's probably a windows port of diff on the net somewhere --h2g2bob (talk) 12:14, 29 May 2007 (UTC)

Live Boot Cd image file[edit]

Dear Ubuntu Fan's, I made the mistake of copying the Ubuntu CD files under WinXP to a cd instead of extracting and burning the iso-image of the cd.So now my boot cd does not boot as it does not posses the ubuntu7.0 livecd boot image file, as burning the files under Nero uses its own default Dos image.Would be grateful if someone extracts that livecd boot image file in iso-buster and mail it to me.My version is ubuntu 7.04 and its for the intel p4 32 bit system.

It would probably make more sense to download the ISO image and burn it again, than to ask someone to email it to you. The download is free. --Tony Sidaway 11:59, 29 May 2007 (UTC)
Depending on where you live, you may be able to get a copy sent by post. See --h2g2bob (talk) 12:18, 29 May 2007 (UTC)
I wanted only the boot image file of the live cd(<1mb), not the entire iso file(700MB)..~~
IIRC, the boot image file is one of the visible files in the CD, so you probably copied it as well. There is no need for special tools to get to the boot image. Looking at my old (6.10) CD, I'd guess it's /isolinux/isolinux.bin, and it's probably a no-emulation image. --cesarb 23:45, 29 May 2007 (UTC)

Images onto Powerpoint[edit]

How can you put a different image that you want as a slide design onto slide master? Slide master only lets you put one image as a slide design for the whole Powerpoint. -- 07:06, 29 May 2007 (UTC)

Do you mean you want to use different slide masters for different sections of your presentation? If you're using PowerPoint XP or later you can create multiple mastersMatt Eason (TalkContribs) 18:04, 29 May 2007 (UTC)
The way I did it with mine was to create a powerpoint with slides using different design. Then I copy-pasted the slide to get a duplicate and put content on the duplicates. --Wirbelwindヴィルヴェルヴィント (talk) 02:11, 30 May 2007 (UTC)

One Time Pad "theoretically unbreakable"[edit]

I've long understood that One Time Pad ciphers are theoretically unbreakable - this makes sense to me. How does this change when the process used to generate the pad isn't truly random?

For example, say my alphabet is {0,1} and my message is one letter long, so my pad is just an element of {0,1}. If a have a truly random pad, then my message is equally likely to be 0 or 1, and both possibilities are, well, entirely possible. But if say my random pads aren't so random and a cryptanalyst knows that my pad is slightly more likely to be 0 than 1, then so what? Then one of the possibilities is slightly more likely, but both are still entirely possible, right?

I guess what I'm asking is that does "unbreakable" in the sense of a perfect OTP mean not only "no one can be sure what the message was" but also "no one has any reason to guess one message over another"? -- 09:18, 29 May 2007 (UTC)

Randomness is an extremely complex topic. A slight bias towards one value or another isn't such a problem (but consider the possibility that p(0) = 0.999), but more problematic for cryptographic purposes is the case where the pad is multiple elements long, and there's a statistical correlation between one value in the next in the pad. In practical terms, it seems that some level of imperfection in the non-randomness can be tolerated. See our article on one time pad for details. --Robert Merkel 09:34, 29 May 2007 (UTC)
Oh, careful, a slight bias is a huge problem. Suppose that the sender wants to help the attacker a little bit. He creates a message using an Error-correcting code and puts it through your biased one time pad. The attacker gets the cyphered message and applies the ECC to recover the original message. ECCs can easily go through a 49%/51% biased cypher, no problem at all. Now if a specially crafted message can be recovered by the attacker exploiting redundancy, why should an attacker not be able to recover a normal message by exploiting the natural redundancy of these messages?
Real one time pads have historically been drawn by hand using lottery machines. There is some case in history where the amount of shuffling the machine does was reduced to save time, and the cypher was broken as a result, but I cannot remember when or where that was, so maybe it's an urban legend.
I believe that it was in Singh's "The Code Book" that I read about the Allies taking advantage of handmade Axis one-time-pad ciphers. Since they were handmade on a typewriter, they tended to use alternating right-hand and left-hand keys. They also favored the middle row of keys. So, instead of having to guess at any possibility, the code crackers could try the combinations that were most likely. --Kainaw (talk) 13:02, 29 May 2007 (UTC)
There's also an amusing scene in Neal Stephenson's Cryptonomicon where a secretary whose job was to make one-time-pads by shaking a basket of chips with letters on them and selecting one would discard some of the choices if she got some combination, three-Zs in a row, say, that she felt was not "random enough", since what are the chances of three Zs? :) --TotoBaggins 14:21, 29 May 2007 (UTC)
I'd like to point out that you're touching on the topic of stream ciphers with your question. Stream ciphers are essentially one-time pads, but instead of using a random number generator, it uses a pseudo-random number generator. It has its advantages (like a key is just one number, not a whole string), but it is also much weaker than the one-time pad (well, technically all non-perfect ciphers are infinitely weaker than the great Cipher of Vernam, but you know what I mean). It's an interesting topic, this --Oskar 11:09, 30 May 2007 (UTC)

How to Program?? Do you use any kind of software?? I just a noob (currently on software).[edit]

Just like the title.

-how to program. actually I know the java and the C language.

THE PROBLEM IS that I need to know how you put the language "in" and program something.

Is there any type of software you use??

Please. I need help. 11:13, 29 May 2007 (UTC) Thomas Gagliardi

At a bare minimum you need a text editor and a compiler or interpreter. You can (arguably) make life easier for yourself by using a source code editor, within or without an integrated development environment. — Matt Eason (TalkContribs) 11:25, 29 May 2007 (UTC)
For java, you can download and run a cross-platform integrated development environment (IDE) such as Eclipse. This gives you a single solution to build, compile and debug programs.
For C or C++ on Microsoft Windows, download Visual C++ Express, which provides a Windows-specific freeware IDE for C++, which can also be used to compile C programs.
For C or C++ on UNIX-like systems, try an IDE such as Anjuta, which provides facilities similar to those provided by Visual C++ Express. --Tony Sidaway 11:52, 29 May 2007 (UTC)
Or just use GCC... However, how do you know how to program if you have never programmed? Just very curios on my part. Did we develope the "Whoa, I know Kung-fu" style of learning already? --Wirbelwindヴィルヴェルヴィント (talk) 02:07, 30 May 2007 (UTC)
Try Dev-c++ or WxDev-c++ there both free and just as good as vs. --Lwarf Talk to Me! 08:32, 30 May 2007 (UTC)

Query question in MSAccess2000[edit]


Hi: I'm trying to figure out how to combine a parameter query and an update. They don't have to be in the same query. What I want to do is this:

Search for a string in a memo field, and update a different field for all the returned records with the same string.


Search on MEMO field = 'Chesterfield', action = update FURNITURE field with 'Chesterfield' in records returned in chesterfield search result. The search on the MEMO field needs to be a parameter query because I'm searching for a bunch (potentially huge number, over time) of different strings. Anchoress 11:49, 29 May 2007 (UTC)

Got an answer on THIS board. Anchoress 13:13, 29 May 2007 (UTC)

Domain Squatting[edit]


A while ago I had purchased a few domain names. It was before I really knew what I was doing. I had bought one domain name with a .org that was from another company with a .com. I recently recieved this email. Should I just give it to them or are they bluffing? Any thoughts would help.

Dear Mr. Malowsky,

Your use of the URL “” violates our registered trademark of the term “______”. Please cease and desist any further use of our trademark including the URL “” within 7 days or we will take the appropriate legal action including recovery of incurred attorneys’ fees. Thank you in advance for your prompt attention to this matter.


They must pay for the domain. There are multiple cases in the past that back this up. For example, Madonna had to pay the owner of for the domain. Brad Pitt had to pay the owner of for the domain. Also, a registered trademark is only for the area of business. For example, I can sell McDonald's car tires without worrying about a lawsuit from the McDonald's restaurant chain - because car tires do not fall under the fast food area of business. So, unless you have a website that is in the same area of business as their trademark, they have no case. Again, there are past examples of a company (Discover credit card company) trying to steal a domain name ( by claiming a trademark and failing because the content of the site had nothing to do with their area of business. --Kainaw (talk) 14:21, 29 May 2007 (UTC)
Uh, careful there, read this: Uniform Domain-Name Dispute-Resolution Policy. The board granted madonna her domain name, she didn't have to pay a cent. OP, if you're domain squatting in bad faith I advise you to give them the domain name. Otherwise tell them no or offer to sell it. --frotht 14:58, 29 May 2007 (UTC)
My memory was that Madonna had to pay the remaining amount the owner paid for the domain - something less than $35. That is easily seen as "not paying for it". However, it is an issue that the owner paid $35/year for the domain and legally deserved a refund. Of course, I could be completely wrong about the whole thing. It was a long time ago. --Kainaw (talk) 16:41, 29 May 2007 (UTC)
I remember a case where some gamer kid who called himself "Sting" had, and the singer Sting tried to take it from him, on the grounds that that wasn't even the kid's real name, and IIRC the ICANN people were like, "um, it's not yours either". :) --TotoBaggins 17:04, 29 May 2007 (UTC)
We cannot give legal advice. Consult a laywer. We do have an article on cybersquatting. — Matt Eason (TalkContribs) 15:01, 29 May 2007 (UTC)
Sure we can. The page you are linking to does not forbid us to, as far as I can see. We might not be prepared to take responsibility for the consequences of following our advice, though. That page, along with the medical disclaimer, appear to me as stemming from the silly habit of some americans of suing eachother whenever they did something foolish because of what someone else said or didn't say. (Along the lines of "It said nowhere on it that I couldn't swallow the whole, unopened bottle of Coke I bought from you!".) I'd be happy to take legal advice from you people, and I would of course take responsibility for my own actions and not just run off and blindly do whatever you told me to do, without considering that you might be wrong or that I might have misunderstood you. I for one don't want the great guide to knowledge that is Wikipedia to have blind spots over the areas of law and medicine. —Bromskloss 18:12, 29 May 2007 (UTC)
The header of that page is pretty explicit - "WIKIPEDIA DOES NOT GIVE LEGAL OPINIONS". The header of this page also makes it clear that people should not request legal advice (although to be fair, the questioner did ask for 'thoughts' and not 'advice'). In some (many?) jurisdictions it's illegal to provide legal advice if you're not a legal professional. We can absolutely give legal information - that's why we can have articles like DMCA and Roe v. Wade. The problem is when we start giving legal advice on specific cases. — Matt Eason (TalkContribs) 18:47, 29 May 2007 (UTC)
This is exactly right. In the state of Florida, it is illegal to practice law or give legal advice without a license- which is where Wikipedia's (and the rest of Wikimedia, I believe) servers are. Wikipedia cannot give legal advice because it would be a violation of Florida state law. That simple. -- Phoeba WrightOBJECTION! 19:51, 29 May 2007 (UTC)

Personality module[edit]

We don't have an article on it, and googling doesn't tell me what I want to know. Can anyone here tell me (in terms a liberal arts major will understand) what a "personality module" is? —Angr 15:04, 29 May 2007 (UTC)

In what context have you seen this phrase? I can't help but think of the products of the Sirius Cybernetics Corporation. --LarryMac | Talk 15:15, 29 May 2007 (UTC)
Haha, exactly what I thought. Googling it seems to suggest something to do with networking or signal processing (there are references to Cisco Analog Personality Modules), but I can't find a definition for it anywhere. — Matt Eason (TalkContribs) 15:22, 29 May 2007 (UTC)
I've seen it in a document I'm translating out of German into English, which means I can't go into much detail for fear of revealing the customer's trade secrets. But it's definitely part of the software (or the software's hardware, like a PCB would be) of some piece of machinery, probably ultimately related to working sheet metal. —Angr 16:25, 29 May 2007 (UTC)
It could really mean anything. A module is just a removable part (software or hardware). A "personality" in computing usually means that it's emulating (pretending to be) some other system for compatibility reasons. For example, Linux can pretend to be other systems (such as SCO Unix or HP/UX). That said, it's easy to imagine a game like The Sims having an aftermarket for "personality modules", so it's really going to be dependent on your application. --TotoBaggins 17:00, 29 May 2007 (UTC)
Well, it's clearly not gaming. The product is for sheet metal producers, not the general public. Knowing that a "personality" in computing relates to emulation helps; thanks! —Angr 17:07, 29 May 2007 (UTC)
That's my point: it could be anything from emulation to gaming, and is totally context-dependent. I don't think you're going to find an answer not specific to your actual machine/system. --TotoBaggins 20:14, 29 May 2007 (UTC)

It might also mean a skin (computing). StuRat 17:14, 29 May 2007 (UTC)

Well there's no guarantee that by 'personality module' they were referring to emulation. Sure, it fits, but it's not a guarantee. A module could be a place where data or information is contained in a piece of hardware. Rfwoolf 17:23, 29 May 2007 (UTC)

I think it's that thing that Bush had on his back under the coat during the debate[1]. Gzuckier 19:23, 29 May 2007 (UTC)
Ha ha. But the upshot is, there isn't one familiar device everyone calls the "personality module". Rather, the makers of this specific machine called something-or-other the "personality module", and in practice it could be almost any kind of module, possibly but not necessarily relating to emulation. —Angr 04:18, 30 May 2007 (UTC)

Bulk SMS messages[edit]

Does anyone know of a web-based or downloadable program that is able to send bulk SMS messages (i.e., to many different people at once) on a specific schedule? Preferably the program would run on OS X or the web, but Windows would also do. Thanks. --MZMcBride 19:15, 29 May 2007 (UTC)

Check out [2] for information on sending bulk SMS messages. You can send to UK only, up to 500 messages a month, I beleive, for free - the full information on pricing can be found here [3]. Jhfireboy I'm listening 23:48, 29 May 2007 (UTC)
Thanks for the response. Cheers. --MZMcBride 01:22, 30 May 2007 (UTC)

Wiki farm questions[edit]

I recently created a wiki on the wiki farm I have been looking at MediaWiki's user's guide and some of there their other Administrator pages but it isn't very helpful.

First, I don't think that I have access to the LocalSettings.php file becuase elwiki holds it, so I'm not sure how much I can change on the programming side of the wiki. So if I do have access to this file, how do I access it? Secondly, how do I change the text on the tabs? For instance, how would you change 'edit' to 'edit this page'. Thirdly, how do I protect pages and give other users sysop status? Finally, is there a way to create namespaces without having access to the LocalSettings.php?

If there is anything else I need to know please tell me, I am familiar with the markup and general wiki editing knowledge becuase of my work here to Wikipedia. Thanks for your help. Scottydude talk 21:31, 29 May 2007 (UTC)

I can't answer all of your questions, but I do know the answers to some of them. A lot of the interface is changeable through a page called Special:Allmessages. On that page you'll see all of the system messages listed, including one called MediaWiki:Edit, which is the one you want to change for your particular question. Whoever originally set-up the MediaWiki software had to create a root account, usually called WikiSysop, who has the ability to protect pages and create admins. Admins are created in the Special:Userrights page, and a page protection tab is available to admins and the root account. I'm pretty sure that new namespaces require access to LocalSettings.php. As for how to access the file, I'm not sure on your configuration (the link you provided doesn't seem to be working right now). Some other pages you may be interested in are MediaWiki:Common.css, MediaWiki:Monobook.css, and MediaWiki:Common.js. Those stylesheets and javascript pages contain a lot of useful code that does things like hide the H1 header on the Main Page. Hope that helps. Cheers. --MZMcBride 23:47, 29 May 2007 (UTC)
Thanks so much! Scottydude talk 23:51, 29 May 2007 (UTC)
Note: The link isn't working becuase the elwiki server seems to be down, I can't access the wiki either. Scottydude talk 23:56, 29 May 2007 (UTC)

Server-side program[edit]

I want to create a website that communicates with a chatbot that I created, something along the lines of [4] and [5], the chatbot is written in C# and I know how to create the a simple form that has "get", therefore trying to open "www.(myWebsite).com/something?input=(what I wrote here)", although, from what I read, I think I should really be using "post" because the chatbot learns and would get messed up with multiple inputs, I just need to know how to get the client data as it's set to me and run it through my main method, I think it has to do with the stuff after the question mark. Please help, and also I don't really want to learn another computer language so try to give me advice related to C# (and Microsoft Visual C# 2005 Express Edition), thanks, 23:13, 29 May 2007 (UTC)

You'll want to look into ASP.NET. You can access the query string through Request.QueryString and postdata through Request.Form — Matt Eason (TalkContribs) 23:23, 29 May 2007 (UTC)