Wikipedia:Reference desk/Archives/Computing/2008 August 18

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August 18

Glibc Source Code

How can I browse the source code of the Glibc without downloading the whole ~GB (ie. one source file at a time)? Thanks, *Max* (talk) 02:04, 18 August 2008 (UTC).

Check out dietlibc, uClibc, Newlib and Klibc if your looking for a smaller C-Library. ---J.S (T/C/WRE) 02:34, 18 August 2008 (UTC)

By looking at the entry in FSF's Free Software Directory (http://directory.fsf.org/project/libc/), you can find a link to the "VCS Repository Webview", at http://sources.redhat.com/cgi-bin/cvsweb.cgi/libc?cvsroot=glibc which lets you not only view one file at a time, but also view the older versions of the files. --tcsetattr (talk / contribs) 05:11, 18 August 2008 (UTC)

Google Code Search is another good option. --Sean 69.134.125.84 (talk) 06:22, 18 August 2008 (UTC)

Thanks for your help. I already checked Google Code Search and it was oddly missing, but the other link was very helpful. *Max* (talk) 18:44, 18 August 2008 (UTC).

Main Menu in Ubuntu

Okay, I had just uninstalled Abiword (A word processor program) because it was inserting weird characters into any document I'd write(I later found out it was the "insert non-printing characters" option which marks all the spaces and paragraphs) and decided I didn't want it in the Main Menu. So I went to System-->Preferences-->Main Menu and deleted the Abiword icon from the list. But later when I found out the problem I couldn't restore the icon(It was not in the trash) so I really can't access the program(Which is quite good). Can someone help me? Thanks.--Xp54321 ^{(Hello! • Contribs)} 02:11, 18 August 2008 (UTC)

I gotta say, I find it odd that your throwing a program away because you had an optional feature turned on. In any case, if you re-install it, it should give you the icon back so you an uninstall it. I'm not an expert on your OS, so I'm not 100% sure. ---J.S (T/C/WRE) 02:39, 18 August 2008 (UTC)

Well you see I thought it was a problem because I didn't know it was a feature. I thought it was a problem. And no the icon does not return, I've attempted re-install about half a dozen times now....--Xp54321 ^{(Hello! • Contribs)} 02:41, 18 August 2008 (UTC)

Oh. Sorry my assistance was worthless. :( ---J.S (T/C/WRE) 01:13, 19 August 2008 (UTC)

You can add items into your main menu using a similar process to how you deleted it. If you go back to that "Main Menu" preferences box. There should be a button with "New Item". In the next box that pops up, select "Application" from the drop down box, the name can be whatever you want, but I guess "AbiWord" will do. And for the command put "abiword" (no quotes, all lowercase). That should work. - Akamad (talk) 08:52, 18 August 2008 (UTC)

Okay then, I'll try that now. Thanks.--Xp54321 ^{(Hello! • Contribs)} 14:39, 18 August 2008 (UTC)

It worked! Thank you so much!:)--Xp54321 ^{(Hello! • Contribs)} 14:40, 18 August 2008 (UTC)

I have a new question. Are there any programs available for Ubuntu that can play flash videos?(Default format of Youtube Videos files int his format end in ".flv") after they've been downloaded? I can watch youtube videos but after downlaoding them with Video DownlaodHelper I can't seem to play them with Ubuntu's default movie player. Or am I impatient and it should in fact play? I have Ubuntu 8.04 LTS Desktop Edition. --Xp54321 ^{(Hello! • Contribs)} 22:27, 19 August 2008 (UTC)

Flash Video mentions several players that run under Linux. The VLC media player mentions Ubuntu explicitly. Algebraist 22:31, 19 August 2008 (UTC)

Thank you very much.--Xp54321 ^{(Hello! • Contribs)} 22:39, 19 August 2008 (UTC)

Okay I tried it out with a youtube video that i downloaded. The video loaded and began to play, but I heard no sound! No audio whatsoever. Sight but no sound. Any reason for this?--Xp54321 ^{(Hello! • Contribs)} 22:53, 19 August 2008 (UTC)

Perhaps you're lacking a required audio codec. Algebraist 23:03, 19 August 2008 (UTC)

And how do I get the required codec? Or even find out what I need?--Xp54321 ^{(Hello! • Contribs)} 23:09, 19 August 2008 (UTC)

In WinXP, the operating system can determine the audio format of a video (rightclick-> properties -> summary). Ubuntu might have something similar. Algebraist 23:20, 19 August 2008 (UTC)

You may need to install the "ubuntu-restricted-extras" package. - Akamad (talk) 23:24, 19 August 2008 (UTC)

I already had the Ubuntu restricted package. I went ahead and got the Kubuntu restricted package as well. BTW I looked at the properties. This is one thing it said about the video under audio: Codec: MPEG 2 Audio, Layer 3 (MP3)--Xp54321 ^{(Hello! • Contribs)} 23:44, 19 August 2008 (UTC)

It's working now. No idea what got it working......--Xp54321 ^{(Hello! • Contribs)} 01:40, 20 August 2008 (UTC)

facebook wall spam

What is Facebook wall spam? How does it work? Does the sender have to install a compromised application on facebook? I recently got one that says:

Kyle Bronowski wrote at 9:59pm LOL! did you guys see what happened on the news today? check it out http://newvids.vidid902812.facecooks.com/

Is there anything I can do to stop it or minimize it in the future? Thanks. Kushal (talk) 03:36, 18 August 2008 (UTC)

Just delete it? I mean, is it that common? Your friend probably has 10 million messages telling them that their account is compromised already. I've gotten wall spam maybe once or twice—I don't think it's really worth spending much time worrying about at this point. (That is, as a user of Facebook, not as, say, an admin.) --98.217.8.46 (talk) 03:48, 18 August 2008 (UTC)

Also—it seems unlikely that you would ever be able to do anything on your end to stop wall spam if it is really being sent by compromised friends of yours. The place to stop it would have to be on the admin end of things—e.g. watching for accounts that post links to certain domains or whatever. --98.217.8.46 (talk) 03:50, 18 August 2008 (UTC)

Hmm. It seems to be becoming prevalent in my school network. I had seen a lot of it on my home page going back and forth across other people's walls but this is the first time that I got hit. I don't think I did anything lately that could have triggered this. Any more ideas?

If it's not actually being posted from your account then it's nothing to do with you (ie you didn't do anything to trigger it). The only thing you can do is get your not-so-lucky friends to change their passwords, since it's their accounts which are being used to post it. Their passwords have been phished - I visited the URL you posted and it redirects to a phony Facebook login page (fanebook.com - don't visit!). — Matt Eason ^{(Talk • Contribs)} 18:53, 18 August 2008 (UTC)

Thanks, Matt. I think Mozilla Firefox should blacklist these phishing websites, and they will probably do that pretty soon. I guess I will talk to Kyle about it in meatspace. Kushal (talk) 16:42, 19 August 2008 (UTC)

I've just had a look in Fx3 and it's been blacklisted already. Not sure how long it's been blocked (I checked in Safari before) — Matt Eason ^{(Talk • Contribs)} 16:52, 19 August 2008 (UTC)

Excel Question

I'm really bad at computing so please bear with me. I need to find all the values that satisfy a certain formula, say x² + y² + z² = 100, in Microsoft Excel 2003. I've no idea how to do this so is there someone who can help me? —Preceding unsigned comment added by 203.219.97.155 (talk) 10:12, 18 August 2008 (UTC)

I assume that x, y and z have to be whole numbers here. Basic strategy is to create a list of possible values for x, y and z and then test x² + y² + z² for each set of values in the list to see if it is 100. Trick is to reduce the list to a reasonable size by applying a bit of thought first. Here are some hints:

• There is no point including any value for x, y or z that is less than -10 or greater than 10 - can you see why ?
• If there is a solution with a value a for x, say, then there is another solution where x is -a - can you see why ? So you only need to include possible solutions where x, y and z are all greater than or equal to 0.
• If there is a solution, say (a, b, c), then there are also several other solutions which are "permutations" of this one; (a, c, b), (b, a, c) etc. So you only need to include possible solutions where x >= y and y >= z.

Use these hints to create a reasonably small list of possible solutions in Excel (you should find there are less than 300 possibilities) then use the IF function to test whether x² + y² + z²=100 for each one.

Not sure why you want to use Excel to solve this problem though. If you don't have to use Excel, then you might think about using a procedural programming language or a programmable calculator instead - you can write an appropriate search with about 4 or 5 lines of code. Gandalf61 (talk) 11:02, 18 August 2008 (UTC)

There's no point including negative numbers at all in your search. Because they're squared, x, y, and z can be either, so you only need to run it once, then create a congruent negative list. Matt Deres (talk) 17:08, 18 August 2008 (UTC)

All of the above will work for finding solutions to x² + y² + z² = 100 specifically, but the original poster said that that was only an example. The answer to the question depends very much on what it's an example of. Do you need an automated system that will solve equations typed in by a third party? -- BenRG (talk) 18:52, 18 August 2008 (UTC)

Office has a formula solver, just for this kind of thing. Check out microsoft's article/tutorial on it here. I've used third-party solvers before, and they gets the job done. The more complex the problem, the longer the application will take to run. ---J.S (T/C/WRE) 00:31, 19 August 2008 (UTC)

I just had a problem in a book saying to use a spreadsheet, the example in the book was Microsoft Excel, to find all the combinations that satisfy this equation- x² + y² + z² = 390.220.244.75.174 (talk) 05:28, 19 August 2008 (UTC)

The Excel Solver tool is a good idea if you just want to find one solution, but it is difficult to use it to find all solutions. A simple extension of the above search strategy will work for x² + y² + z² = 390 - you just get a larger set of possible solutions. You can cut down the set of possible solutions a bit more by noting that the largest of x², y² and z² (let's say it is x²) must be at least 390/3, which is 130. So x must be at least 12. An alternative strategy is to pick values for x and y from a set of feasible values and then test 390 - x² - y² to see if it is a square number. Gandalf61 (talk) 09:12, 19 August 2008 (UTC)

good audio editor

hi im looking for a good, free, internet downloadable program for editing audio, like Nero, but for free:) thanks...--84.71.99.232 (talk) 10:59, 18 August 2008 (UTC)

Audacity. Which operating system (eg. Vista, Tiger etc.) are you using?78.151.54.224 (talk) 11:04, 18 August 2008 (UTC)

Windows XP is what im on..........also do you know how to record sound via the input microphone hole in the back of the computer.....i know there is a sound recorder in accessories but to be honest its only 60 secs which is useless. Will Audacity record stuff from the 'microphone hole'?--84.71.99.232 (talk) 11:15, 18 August 2008 (UTC)

It sure will. the wub "?!" 12:26, 18 August 2008 (UTC)

If you have the right drivers so the mic is recognized as an input...--droptone (talk) 12:38, 18 August 2008 (UTC)

MSN, Hotmail and Safari

I have a problem which is annoying me.

I use Microsoft MSN on my apple macbook pro ( 10.4 ). When i click on the mail icon, it takes me to my hotmail inbox.

However now, every-time i click, i HAVE to re enter my password to gain access. The options to 'remember it' are there, but they dont work.

Is this Microsoft's response to weakened web security? Surely having to retype my password all the time is more of a risk? How do i stop it?86.157.85.114 (talk) 11:58, 18 August 2008 (UTC)

I have had similar problems with some sites with Safari—no matter how many times I try to get it to "remember" the password, for some reason it often just won't, even though I've got cookies enabled and etc. I don't think it's a Microsoft-specific problem, I think it has something to do with how Safari remembers cookies or sessions or whatever. It's maybe the only thing about Safari that drives me nuts on a regular basis. --98.217.8.46 (talk) 12:41, 18 August 2008 (UTC)

Here's a post and set of responses about this very problem. One possible solution suggested, but I don't know—I've never started Safari in Rosetta (why would one do that? I have no idea) personally and I still have this problem. But I'll give it a shot... --98.217.8.46 (talk) 12:47, 18 August 2008 (UTC)

Adobe Shockwave is only available in Rosetta (binary translation software). That could be a reason. Kushal (talk) 13:00, 19 August 2008 (UTC)

"Surely having to retype my password all the time is more of a risk?" Am I missing something obvious here? Why would storing that password in your head be more of a risk than storing it in the computer where it could be used if the computer was stolen or used without your permission and/or knowledge? -- Captain Disdain (talk) 16:15, 18 August 2008 (UTC)

Yeah, storing your password in non-encrypted memory space is actually more risky then typing it in each time. Both are vulnerable to the exact same situation however. If your computer is breached, then it's lost either way. ---J.S (T/C/WRE) 00:25, 19 August 2008 (UTC)

I think it is more of a matter of preference at the Windows Live Hotmail team than a matter of security. If it were not secure enough, why would Google's Gmail and Yahoo!'s Yahoo! Mail allow you to save passwords? Kushal (talk) 16:39, 19 August 2008 (UTC)

SIS

Hi. I read the article on NTFS and came to this SIS (single instance storage) but couldn't clearly make out.Can someone explain me this a bit.Thanks —Preceding unsigned comment added by 59.103.25.107 (talk) 14:12, 18 August 2008 (UTC)

Have you read the references on Single instance storage? If so, do you have any specific questions? I'm not sure how to explain it more clearly than on the page. Gyroggearloose (talk) 20:14, 18 August 2008 (UTC)

Ok, here's an example: Lets take an e-mail server. Lets say there are a dozen people who use that e-mail server. Lets also say that one of the users chooses to send out an e-mail to everyone on the server. A e-mail server that utilizes SIS 12 exact copies of that message are going out, and instead of making 12 copies, it simply stores 1 copy of the message and adds "pointer" to that message in each person's mailbox. In this example how much data the server needs to store for that message is reduced by 91%.

When your talking about large enterprise data-servers, the savings can be even more drastic. The organization I work for has ~300 "My Documents" folders. Each folder likley has the exact same copy of our corporate Standard Operating Procedures. This file is about 10 megs. 10 megs * 300 copies = ~3gigs. If we were using the SIS the server would only be keeping one real copy and 299 pointers (basically shortcuts), saving ~2.99 gigs of storage.

I hope this helps. ---J.S (T/C/WRE) 01:03, 19 August 2008 (UTC)

Is it worth replacing Windows firewall?

A website that compares firewalls says that Comodo is the best free firewall. Not being a computer nerd/geek/etc, I wonder if its worth changing to Comodo. What worries me specifically is then when I install new programs, they may be able to update Winfows firewall automatically with no input from me, but if I use Comodo then a lot of manual tinkering with settings may be required (for existing programs too) which I am not competant to do. I have XP SP3.

Another related question please - I have just moved to XP after using a WinMe computer with a free copy of ZoneAlarm. ZoneAlarm was rather busy - you could change the setting for indivdual programs and get details of blocking done. However, Windows Firewall is completely silent - all you can do is turn it on or off. Why is this, and does it imply WF is not very good, even though my various anti-spyware and anti-virus scans have not found anything getting past it? Thanks 78.149.219.203 (talk) 14:28, 18 August 2008 (UTC)

Windows Firewall is (or at least was, on last check) rather limited in its approach. Its pretty good with unsolicited incoming requests but it totally ignores outgoing messages. As long as your system is uncompromised, Windows Firewall should suffice. If you think your machine is already compromised, you need more than Comodo Firewall. Kushal (talk) 18:12, 18 August 2008 (UTC)

If your system is compromised, you had better assume any firewall software you have is as well. -- Consumed Crustacean (talk) 04:00, 20 August 2008 (UTC)

Based on the leak tests I've done, Windows Firewall works great for inbound protection. The main drawback is that it doesn't provide outbound protection. That is, it doesn't prevent programs from "phoning home." Windows Vista's firewall does do this. Another drawback, as you mentioned, is that it doesn't provide feedback. Of course, it still keeps a text log that you can view to monitor activity. You can also build your own firewall by going to Start --> Run --> secpol.msc and creating your own rules from IP Security Policies on Local Computer. You can also just disable services that you don't need. Many of these listen for connections from other computers and allow worms to spread. This site tests your firewall for leaks: http://www.grc.com/. The main difference between Windows Firewall and third-party firewalls is ease-of use. Any firewall you use will often be compromised if you have a virus infection. I had Zone Alarm once and it was rendered useless by a virus infection. Now I just use Windows Firewall.--J4n56t (talk) 18:18, 18 August 2008 (UTC)

Authorative independant website that objectively compares and recommends freeware etc anti-virus/spyware software.

Also gives other security information. It was not a slick commercial site. It went into a lot of detail. Does anyone know which website I mean please, as I cannot remember its name? Thanks 78.149.219.203 (talk) 14:34, 18 August 2008 (UTC)

Doesn't Cnet run a website called Download.com or something like that that offers freeware/shareware downloads? I think it also gives reviews since it's Cnet.Coolotter88 (talk) 19:42, 18 August 2008 (UTC)

Not sure if this is what you're looking for, but the site for the Kim Komando show has a lot of freeware and downloads and things like that. --Alinnisawest(talk) 19:44, 18 August 2008 (UTC)

Perhaps it was Tucows? Laenir (talk) 20:11, 18 August 2008 (UTC)

Thank you, but it was not a general download site. In fact it probably didnt have any downloads. It compared, ranked, and recommended various security/privacy software, including freeware and commercial software. It ranked SuperAntiSpyware as being on of the best freeware programs. The website was mostly about keeping your computer secure/private; recommending software was a minor part. 78.146.203.138 (talk) 22:00, 18 August 2008 (UTC)

Sorry I can't answer your question. All I can say is that anything on FileHippo.com is the best of the best software wise. I recommend every piece of software on their site. --mboverload@ 22:50, 18 August 2008 (UTC)

The purpose of Webdings and Wingdings

Does anyone have the answer as to why webdings and wingdings were created and what purpose do they serve? I couldn't really find that information in the articles. Thanks and cheers, 10draftsdeep (talk) 16:29, 18 August 2008 (UTC)

They don't have a lot of function now. In the prehistoric time of computers, you had limited graphics. For example, you might have 80x40 characters and 4 sprites (a sprite is an image that you can place on the screen anywhere you like). Since you primarily had to create your graphical display with characters, character sets were created that had all kinds of shapes that you could use, saving you the need to use your limited number of sprites. -- kainaw™ 17:54, 18 August 2008 (UTC)

They can (very) occasionally be useful for design work. I've used the Wingdings scissors for 'cut here' lines a few times. — Matt Eason ^{(Talk • Contribs)} 18:41, 18 August 2008 (UTC)

"ASCII art" might be of interest. ---J.S (T/C/WRE) 00:44, 19 August 2008 (UTC)

Fonts like this are much older than computers—see our article on dingbats. Wingdings and Webdings are just computerized dingbats. --98.217.8.46 (talk) 03:14, 19 August 2008 (UTC)

Thanks to all for the information. Also, I was always interested in ASCII art but never knew the proper name of that technique. Thanks again everyone...and cheers, 10draftsdeep (talk) 14:17, 19 August 2008 (UTC)

Uniquely identified USB flash drive

Hi, I'm wondering if it's possible to uniquely identify a USB flash drive on a network - that is, if someone plugs their USB flash drive on one computer that's part of a network, and then the next day plug it into a different computer on the same network, would I be able to tell that the same flash drive was used? Does this technology exist and if it does (since I'm not very savvy on this type of technology), how common is it and where is it used (office/workplace, schools, etc)? Thanks. 141.153.214.99 (talk) 19:16, 18 August 2008 (UTC)

I'm not aware of any existing software that would permit this. I do think every USB device has a semi-unique serial number, but I could be wrong on that too. ---J.S (T/C/WRE) 00:21, 19 August 2008 (UTC)

=) Serial numbers included! Track any USB device EVER plugged into a Windows machine. USBDeview. The only automated networked ones that do this are really, really expensive (as far as the products I'm thinking of). --mboverload@ 00:23, 19 August 2008 (UTC)

I'm glad to have that verified. It explains some of XP's strange behavior with printers that I've noticed. 00:36, 19 August 2008 (UTC)

Also, they all have a volume name, which I suspect is assigned when the flash drive is formated and/or the MBR (Master Boot Record) is written. For mine it's "USB 2.0 Flash Disk USB Device", which is 29 charachters. That certainly gives you enough space to provide a volume name which is both unique and meaningful. StuRat (talk) 00:35, 19 August 2008 (UTC)

Address Bar Disappearing in IE

OK, I'm sure it's a simple fix and I think I've actually done it before, but the address bar has completely disappeared from the Internet Explorer that came with our computer. I don't use IE usually, just Firefox, but others in my family do use it, so I need to fix it. Thanks! --Alinnisawest(talk) 19:49, 18 August 2008 (UTC)

Try right-clicking on any of the bars at the top of IE, and you'll get a list of bars you want to view. Select "Address Bar." Laenir (talk) 20:13, 18 August 2008 (UTC)

That doesn't work; the Address Bar is supposedly there, but all that you can see of it is the word "Address". However, a friend of mine helped me out- somehow the toolbars got unlocked, the address bar got shoved over, and they got locked again. Probably some weird program glitch. But it's solved now- you just have to unlock the toolbars and drag it out. --Alinnisawest(talk) 21:08, 18 August 2008 (UTC)

cookies

In firefox, how can i segregate my cookies so that I can log in twice on youtube on different usernames? 79.75.155.198 (talk) 19:56, 18 August 2008 (UTC)

The Cookiepie extension claims to allow you per-tab cookies. -- Finlay McWalter | Talk 20:02, 18 August 2008 (UTC)

Also you could try the Greasemonkey extension and then going to [1] and looking through it. They have some scripts that work that way. Rob^{Not an admin}  21:48, 19 August 2008 (UTC)