Wikipedia:Reference desk/Archives/Computing/2009 February 4

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February 4

Youtube

On Youtube, who is the fastest person to reach 1000 videos? JCI (talk) 00:19, 4 February 2009 (UTC)

YouTube doesn't keep official records of that, so it'll be pretty hard to find out. Also, it's entirely possible (and quite likely) that there are no users with 1000 videos. flaminglawyer 00:28, 4 February 2009 (UTC)

Furthermore, if such a statistic were available, it wouldn't take long for someone to render it completely meaningless simply by uploading 1000 videos that were about a second long each just so that he could break the record... -- Captain Disdain (talk) 00:30, 4 February 2009 (UTC)

(Note that videos have to be at least 1 second long. 3 months ago, I tried to upload a video that was 1 frame long, and it's still in "Upload processing..." stage, meaning it'll never work. This is almost completely irrelevant, but is a bit useful.) flaminglawyer 03:41, 4 February 2009 (UTC)

@Captain, again: It would be a bit more challenging because Youtube doesn't allow you to upload duplicate videos. flaminglawyer 06:10, 4 February 2009 (UTC)

There's no reason why the videos would have to be identical (and in fact, I didn't propose that they would be). It would be a completely stupid use of your time to make them, of course, but far be it from me to underestimate the time people on the internet are willing to use on something completely pointless. -- Captain Disdain (talk) 08:20, 4 February 2009 (UTC)

It would be a relatively easy process to automate tho. Nil Einne (talk) 09:54, 8 February 2009 (UTC)

... (Windows XP)

Are there any computer users who have never heard of Windows XP? JCI (talk) 03:38, 4 February 2009 (UTC)

No doubt, if you really mean "any". I mean, there are probably 6 year old kids who just got on the computer today for the first time who haven't heard of it. Or the very elderly who have put off using computers and just got involved with them. Or lots of people in between who are more tuned out than you'd likely believe (cue statistics about people who can't find their own country on a map). But if you mean, "is the existence of Windows XP pretty well known and should be considered a part of basic knowledge of someone on computers," then yeah, probably. --98.217.14.211 (talk) 03:47, 4 February 2009 (UTC)

I just finished working on a computer for an old lady. When I first talked to her, I asked what operating system was on her computer, and she said, "Oh, Lord. I don't know." I replied "So, does it say 'Windows XP' or 'Windows Vista' when it starts up?" She replied, "No." It turned out it was Vista, but then she wasn't sure how she connected to the Internet. She thought it was cable (she was wrong). You get the idea.--K;;m5m k;;m5m (talk) 04:01, 4 February 2009 (UTC)

Dang. I was going to tell that exact same story. You beat me to it. I'll confirm that old people know nothing about computers. My grandmother even has a book called The Computer Hater's Handbook (which she actually uses quite often). flaminglawyer 06:56, 4 February 2009 (UTC)

I am sure that the Matis Indians of the amazon rain forest have never herd of WinXP. I am also sure that the Afar, Anlo-Ewe, Amhara and the Ashanti tribes of Africa have never even seen a computer.– Elliott  16:28, 4 February 2009 (UTC)

True, but it's also likely they're not computer users. 62.172.106.180 (talk) 17:35, 4 February 2009 (UTC)

I can confirm that there are plenty of such people, but they don't hang out on the refdesks (any refdesk, not just the computer one). I work with university-educated professionals and our organisation has a decent IT helpdesk, we have non-ancient machines (less than two years old), etc. Some of my colleagues... [sigh]. I had to show one how to turn off her computer. Another wanted to know whether the memory stick could go in the floppy drive "because it stores things, right?". Another declines to ever touch a computer, and finds out about staff meetings by osmosis, or misses them. I wouldn't care to ask any of them what their operating system is. People can be of reasonable intelligence but of Luddite tendencies; many prefer ignorance. (All the desktops here run XP.) BrainyBabe (talk) 16:24, 5 February 2009 (UTC)

Children who have received laptops from the One Laptop per Child scheme might be good with computers and be able to do 'fancy things' with the Linux system on there and applications on that system but not have heard of Windows XP. --Joe^Talk_Work 02:26, 6 February 2009 (UTC)

(Yes, and likewise for some Apple users.) I highly recommend a 15-minute film called "Yellow Smiley Face" about two computer-illiterate middle-aged parents trying to make their son's computer work so they can contact him now that he is abroad. I wish I could show it to all highly computer literate people who have to deal with neophytes, to awaken their compassion. It is also extremely funny. BrainyBabe (talk) 07:18, 6 February 2009 (UTC)

Wireless router/hub

I have a question about wireless routers - is it necessary, if you want to connect the computer(s) in your house wirelessly to the internet, to buy one of these? Or could we buy a wireless access point? I ask because we already have a hub provided by vonage, and if I can buy something for cheaper I will. I absolutely cannot continue to work with a wire - my computer does not work properly with them! Magog the Ogre (talk) 06:42, 4 February 2009 (UTC)

A wireless router is a wireless access point with network features built in. If you don't need networking, get a WAP. If you need networking, get a router. I bought a Linksys router instead of a WAP a couple years back because I though that one day I might need networking (at the time I had only 1 comp in the house). Now I have 2 comps, but I still don't need networking because of an invention called "e-mail." So it's a personal preference. Routers tend to look better than WAPs, though. flaminglawyer 06:52, 4 February 2009 (UTC)

So the HUB will only allow one computer... how can I assure that mine is the computer working on it? Does it have a built in ability to only work with certain MACs? Magog the Ogre (talk) 06:58, 4 February 2009 (UTC)

Well the main difference is that a router (gateway) acts as one device to the outside. So if your internet connection only gives you one IP address (it depends on your ISP), and you want to connect multiple computers, you will need a router at some point. A wireless router is just basically a wireless access point hooked up directly to a router. But you could also connect a wireless access point to a separate router, for example if you already have a wired home network. If you connect to the Internet through something like a DSL modem or cable modem, depending on your modem model, it may already have a router built-in, in which case you would not need another router. But having an extra level of router doesn't really hurt (the inner one just acts as one device to the outer one, which then acts as one device to the outside), except make networking between computer on the different routers more complicated. Most people usually get wireless routers instead of access points, because routers are needed in many cases, they are pretty cheap and more widely available in stores, and you can't usually go wrong with a router. --76.167.241.45 (talk) 08:00, 4 February 2009 (UTC)

What do you mean you have a "hub provided by vonage"? If vonage is your ISP, then what they provided you is probably a DSL/cable modem, which may or may not have a router built-in. You would have to find that out. --76.167.241.45 (talk) 08:02, 4 February 2009 (UTC)

I will be compleatly honest with you; You should go to your local Best Buy, CompUSA or Fry's and explain what type of ISP you have, explain that you want to be able to connect more than on computer to the internet, they will be extremely helpful. – Elliott  16:30, 4 February 2009 (UTC)

What are you talking about? If you have multiple computers and only one IP address you NEED a router, unless your modem also functions as a router. What does email have to do with it? You need a network connection for email to work too. .froth. (talk) 20:15, 4 February 2009 (UTC)

By "network connection," you mean the Internet. You don't need a wireless network to send email, but you do need an Internet connection. flaminglawyer 01:04, 5 February 2009 (UTC)

Reread your comment. I have 2 comps, but I still don't need networking because of an invention called "e-mail." You need a home network if you have multiple computers and one external IP. You might be confusing wifi with networking ... .froth. (talk) 18:22, 9 February 2009 (UTC)

Already have a router guys, through Vonage. I was thinking access point bc they come much cheaper on ebay. Magog the Ogre (talk) 05:02, 5 February 2009 (UTC)

How to make .png images visible again on my Internet Explorer 7?

Recently I've realised that .png images are not being displayed on my IE7 browser, although other pictures are. This might be because I uninstalled all traces of quick something (I forget the name), an intrusive media program. How can I make .png images visible again please? 89.240.202.111 (talk) 11:10, 4 February 2009 (UTC)

Apparently, this isn't a completely uncommon problem. First off, I'd like to suggest you get Firefox. It's a powerful browser with a similar setup to IE, only it doesn't break nearly as often as IE, it actually displays pages correctly, and it has fewer security issues.

That being said, it appears your problem is related to removing QuickTime, but that's not because QT has anything to do with .png files, it's because IE decided to break. I don't use IE, but I found some discussions on the topic here and this place has a link to download a fix. Hope it helps! --Alinnisawest,^{Dalek Empress} (extermination requests here) 11:25, 4 February 2009 (UTC)

Thanks, I will follow your links. I just wanted to add that none of the images on this webpage http://www.libpng.org/pub/png/ show, EXCEPT oddly for one only: the metal-plate like image that says "</gif><png>" which appears in the section headed "What It Be (An Informal History)" on that page. 89.240.202.111 (talk) 11:48, 4 February 2009 (UTC)

Thanks for help but I applied the registry fix as suggested by your second link, restarted the computer, but unfortunately I still cannot see png images - I cannot see the two small png images at the base of this page for example. Another change I have recently done is uninstall AVG Free antivirus and install Avast! Free antivirus in its place - why I particulary wanted to see png images was so that I could see the phg image security code so that I can register the program. 89.240.202.111 (talk) 12:09, 4 February 2009 (UTC)

Hmm... I really don't know what else to try. I saw someone suggesting you reset all of your settings (although that'll delete your cookies), check to be sure your file associations haven't been messed up, or try reinstalling (although it sounded like people didn't have much success with this method). Hopefully this works; if not, it might be easier just to get Firefox or Opera. --Alinnisawest,^{Dalek Empress} (extermination requests here) 22:31, 4 February 2009 (UTC)

Making Animated Flowcharts

I am drawing a flowchart for an electronics project and it is required to have some basic 2d animations to explain its working. Like the pulses being generated and where the're travelling to, etc. Can anyone please tell me of such free software by which I can make, maybe, animated gifs. Vector based ones would be better. —Preceding unsigned comment added by 218.248.70.235 (talk) 11:54, 4 February 2009 (UTC)

Synfig is a free vector-based animator. --Sean 13:35, 4 February 2009 (UTC)

GIF

I need a small free program that makes gifs from a few images. thanks —Preceding unsigned comment added by 194.80.240.66 (talk) 12:26, 4 February 2009 (UTC)

Although it's a bit basic, you could do worse than trying Microsoft GIF Animator - It's a rather old product now, but it might do what you're looking for. ZX81 ^talk 13:03, 4 February 2009 (UTC)

If you're using Linux, the ImageMagick tools will do it handily. It's not clear what you want to do, but to convert a non-gif to gif, just do:

convert image.jpg image.gif

or to create an animated gif from other images do:

convert frame1.gif frame2.gif frame3.gif animated.gif

--Sean 13:33, 4 February 2009 (UT

By "makes gifs", do you mean that you want to convert an image from something other than a GIF to a GIF -or- do you want to take a bunch of images and make an animated GIF? As mentioned nearly every time someone asks an image question, GIMP easily converts images. Just open the image and select "save as", then change the extension from jpg or bmp to gif. It also does animated GIFS. Each layer in the image is a frame in the animation. -- kainaw™ 13:33, 4 February 2009 (UTC)

I'm looking to make an animated gif from a series of images. I don't have a Linux, I'm a bit of a n00b when it comes to these things. I did try Microsoft GIF Animator but the quality of the images in the final gif was much worse than the input. How can I preserve the original quality, even if it means a bigger file size? Thanks again —Preceding unsigned comment added by 194.80.240.66 (talk) 13:37, 4 February 2009 (UTC)

The Gimp can do this. It's a bit tricky though. APL (talk) 14:05, 4 February 2009 (UTC)

ImageMagick is also available for Windows. You can get it here — Matt Eason ^{(Talk &#149; Contribs)} 14:12, 4 February 2009 (UTC)

(ec)ImageMagick works fine on Windows. Depending on the kind of images you're animating, you'll find that GIF badly restricts available colours. To begin with GIF only supports a palette of 256 colours. Worse, that palette is shared between all the frames of animation. The restricted palette means that any GIF animator program has to dither your source images down; this means that GIF animations derived from photos will generally look grainy and horrible (although animated diagrams, which have more restricted palettes, work okay). Oh MNG, wherefore art thou. Mimetic Polyalloy (talk) 14:14, 4 February 2009 (UTC)

Me again. I don't understand how to use ImageMagick, whenever I double click the program it flashes a screen of text for about a second and then closes. —Preceding unsigned comment added by 194.80.240.66 (talk) 14:25, 4 February 2009 (UTC)

You need to do it from the "command prompt". Assuming you are on windows, you press <windows>+r, type in cmd (hit enter), and then on prompt that opens you type convert <your image path here> <your new image path here ending with .gif instead whatever it was earlier>. If you are completely new to these things you want to see cd (command) to make things a bit easier.k Also I think windows cmd has tab completion even though I can't verify it right now. --194.197.235.61 (talk) 14:47, 4 February 2009 (UTC)

Yes, it does — Matt Eason ^{(Talk &#149; Contribs)} 14:59, 4 February 2009 (UTC)

I did that and it converted my jpg to gif, but it's not animated. Is there no simple gui for doing this? Ah well thanks anyway, I guess it just wasn't meant to be. —Preceding unsigned comment added by 194.80.240.66 (talk) 15:06, 4 February 2009 (UTC)

Be careful - ALL images (animated or not) look much worse in GIF than in other file formats. That's because GIF uses a 'paletted color' trick to get the file size down. There can only be 256 unique colors in a GIF image. That's fine for simple cartoony graphics with no subtle color blends - but if you put any nicely rendered or photographic material into a GIF - it will look terrible and there is absolutely nothing that anyone can do to fix that. Having said that, GIMP is a great tool for the job - just load up the individual frames of animation into layers and tell it to animate them - then save as GIF. But any loss of quality that results is just a fact of life. SteveBaker (talk) 21:04, 5 February 2009 (UTC)

Amount of dvorak users

How many dvorak users there are in the world? It might be because of my limited English, but I couldn't find anything useful with google. Other numbers than the amount of users in the world would also be helpful. (and should this question be on some other reference desk?) --194.197.235.61 (talk) 13:06, 4 February 2009 (UTC)

I can't find any current information, but did you notice that Dvorak Simplified Keyboard says "In 1984, the Dvorak layout had an estimated 100000 users"? 81.98.38.48 (talk) 19:54, 5 February 2009 (UTC)

You might also want to note that recent studies have revealed that:

1. The dvorak layout is no faster than qwerty.
2. The early promoters of dvorak cheated, lied and otherwise finagled their way into their claim to be faster.
3. The early testing done by various arms of the US government was done with faulty experimental technique and isn't worth the paper it's printed on.

Dvorak needs to "just die already" - it's a pointless waste of everyone's time. SteveBaker (talk) 20:59, 5 February 2009 (UTC)

Ok, thanks for the answers (keep posting if you still have any), especially for the 100,000 I managed to miss, even if it's not too recent/accurate. I switched to dvorak something more than half a year ago so I have to disagree with SteveBaker a little bit, my wpm rose with about 10 with accuracy near 100%, but of course that was as much due to the extra practise it took to get used to dvorak and getting an easy chance to dump my old bad qwerty habits as it was due to dvorak being somehow better than qwerty. I do have a lot less wrist pain now, but the previous point pretty much covers that too. It might be nobody should really switch if they have had years of nothing but good experience on a different layout, but the "pointless waste" piece is slightly exaggerated in my opinion. Depends on from which direction you're looking at this I guess. --194.197.235.61 (talk) 22:09, 5 February 2009 (UTC)

Where are these studies? Algebraist 22:13, 5 February 2009 (UTC)

The thing is, Qwerty is clearly less than optimal. Consider letter frequency: the 8 most frequent letters in English text are E T A O I N S H. Qwerty places 3 of the 8 on the homerow, opting for winners like j and k instead (23rd and 22nd, respectively). Dvorak, however, places all 8 on the homerow (with an unfortunate transposition of U and I). Then we can move on to bigrams: the top 8 in English text are TH ER ON AN RE HE IN ED. Qwerty places 0 of the combinations on the homerow; 4 combinations (TH AN HE ED) have 1 key on the homerow, but one combination (ED) uses the same finger. Comparatively, Dvorak places 6 of the 8 entirely on the homerow. (Incidentally, Dvorak manages a much wider "spread" for these common combinations than Qwerty, which should dispel the myth that Qwerty was chosen to separate subsequent keys for a typewriter.) So, from a purely practical efficiency perspective, Dvorak would indeed seem to be better than Qwerty. Realistically though, the performance gains probably aren't that significant compared to the cost of retraining (and certainly not anywhere near the figures Dvorak claimed). – 74  02:18, 6 February 2009 (UTC)

Implementing structures at a lower level

In programming languages, for example C, you can create your own structures using struct. However, I am interested in finding out how structures would be implemented at a lower level i.e. assembly --212.120.245.203 (talk) 15:19, 4 February 2009 (UTC)

You'd do something like having the address of the structure in a given register, and then you address the fields in the structure with a register+offset instruction (e.g. move #0x21 -> R1+8). Assembly generally has almost nothing by way of type, so such implementations are implicit in the code. That's essentially how C code that addresses structures is compiled. Incidentally if this all feels a lot like handling arrays, that's because array code works in much the same way (except that +8 is computed rather than constant). Mimetic Polyalloy (talk) 15:39, 4 February 2009 (UTC)

You need to be careful choosing that offset if you are interfacing with other than your own assembly code. I believe 99% that standard c requires only the first field of struct to be "on it's place", ie you can cast the struct pointer to the type of first field pointer and get meaningful results. More stricter rules depend on your architecture/os/compiler, google is your friend. If you are on linux go to http://www.linuxfoundation.org/en/Specifications and pick the most relevant. --194.197.235.61 (talk) 16:02, 4 February 2009 (UTC)

Most assembler languages I have seen have no "struct". A struct is just a short-cut in C language to allocate many bytes and tell the compiler how each byte should be interpreted (e.g. first few as an unsigned int, next few bytes as a pointer, etc). It is a shortcut for doing the same set of data operations every time it appears in the code. If you want to allocate several bytes and interpret them in special ways, you simply do that with individual assembly-language instructions. I would go so far as saying that any assembly-language which included complex forms like struct probably gets compiled down to a lower-level language at some point. Nimur (talk) 16:20, 4 February 2009 (UTC)

Yes, that's right (and it's the downfall of many a cleverdicky piece of C, never mind assembly). Some architectures mandate than n-size objects be on n-bit boundaries; to try to address them more finely either makes for un-compilable code (where the assembly can't be rendered into machine code, because that granularity is implicit in the instruction coding) or code that will SIGBUS. Even on architectures which do allow mis-aligned access (IA32, SPARC(kinda)) there is often a penalty of additional cycles to pay. Of course if someone is coding in assembly they don't get to be ignorant of such things (and this is one case C programmers can't ignore either). Mimetic Polyalloy (talk) 17:03, 4 February 2009 (UTC)

Many assemblers (as distinguished from assembly language) do support a "struct"-like keyword. Nasm for example has 'struc' (note: no 't'), and gas has '.struct'. The way these are declared/used is not standardized of course. -- Fullstop (talk) 22:39, 5 February 2009 (UTC)

I think you've misunderstood what I was asking. I know most assemblers don't have a struct keyword or anything that does the same thing. WHat I was asking is what something that would be implementedd in C using struct look like using assembler?

Ubuntu Question

Is there a program that will let me install Ubuntu on to a different hard drive in my computer while running Ubuntu? I am not sure that i phrased that currectly so let me explain. Lets say that i have installed Ubuntu on to a flash drive, i take that flash drive to a friends house and plug it in to his computer, he starts playing around with Ubuntu and desides that he wants me to install it on to his computer, but alas i have forgotten my CD... What i want is to be able to open a program that will go through the instalation of Ubuntu from within Ubuntu. Similar to the built in utility "Create a USB startup disk" Thank you – Elliott  16:54, 4 February 2009 (UTC)

You can put ubuntu on to a memory stick and go from there see here for details. BigDunc^Talk 17:41, 4 February 2009 (UTC)

Also see https://help.ubuntu.com/community/Installation/FromLinux. --194.197.235.61 (talk) 17:45, 4 February 2009 (UTC)

Open a terminal and type: ubiquity (that is the official Ubuntu installer), it should work... SF007 (talk) 17:50, 4 February 2009 (UTC)

Importing whole iTunes Library

hi, ok basically a few days ago i copied the iTunes library/database/whatever file onto my external HD since i have now stripped down and re added everything to my computer. I have now also re downloaded and installed iTunes, so my question is 'how do i re-add/open my previous iTunes library into iTunes, with all the right information and stuff?'. A quick look around the options revealed nothing. (I am using Windows XP). Thanks, --84.68.135.13 (talk) 17:47, 4 February 2009 (UTC)

Make sure iTunes is closed and then just copy the libraries files that you backed up in the first case (iTunes Library.itl and iTunes Music Library.xml) back to your "My Music\iTunes" folder overwriting the new ones that iTunes made when you re-installed it. I would recommend copying the files rather than moving incase there is a problem so you will still have a copy of them. After doing this just reopen iTunes. If the location of the music on the hard disk has changed (i.e. not the same drive and path) you will need to go into the iTunes options and change this to the new path. Hope this helps! ZX81 ^talk 17:59, 4 February 2009 (UTC)

Since I am going to be doing the very same thing soon, please post the results if you try this. I would love to know it works before I take the plunge. thanks and cheers, 10draftsdeep (talk) 21:11, 4 February 2009 (UTC)

As long as you copy both library files (and obviously all the music!), it will work. I've done it myself many times. Sometimes there are other temporary files in the My Music\iTunes directory so you may wish to copy them too, but only the files mentioned above are the ones that are needed. As a side note, I store my album artwork IN the MP3 files, but if you store them on the disk they'll be in subdirectories of the iTunes folder so just copy the whole folder/all files to be sure. ZX81 ^talk 21:27, 4 February 2009 (UTC)

Hacking Challenge

My professor has challenged our class to 'hack' into his laptop that just sits at the front of the room. The strange part is he's a biology professor and this has nothing to do with our class work, apparently he just challenges all of his students to do this. I am very computer literate but I don't really know where to start; I guess I'd need to find his IP address. We're on the same network so it can't be that hard. Any help with this would be great; not only would it just be cool, but I'm always looking to impress my profs! -Pete5x5 (talk) 17:58, 4 February 2009 (UTC)

While your professor is not looking, get to the laptop, (assuming he has windows) press <windows>+r and type in msg * Hacked by <your name here>. That should convince him, but won't be so easy if he's not logged in all the time. --194.197.235.61 (talk) 18:06, 4 February 2009 (UTC)

I don't know if having his IP address would be helpful, but the easiest way to get it is to send him an e-mail that links back to server of yours. (Sometimes even just looking at e-mails he has sent will have the IP address of the sending computer in the headers.) If it were me, I'd probably use the fact of my being a student as a way to get my foot in the door; try to send him an assignment or program or something that was really a custom virus or backdoor program. Of course, whether he'd actually appreciate getting his security very much compromised, despite making it an open challenge, is questionable. --140.247.254.112 (talk) 18:31, 4 February 2009 (UTC)

If you're sure you have permission... well, the obvious way that you can't help learning if you know anything about networking at all..... if his laptop is connected to the network and advertising itself on the windows network as "BioProfLappy" it's pretty obvious which is his, otherwise you're probably going to have to guess. To find his IP address run nbtstat BioProfLappy. You can run something like nmap or I guess Nessus (software) to see what services are facing the network and metasploit or an online database to find shellcode matching one of the daemons (and version).. I've never used it but I think the metasploit client thing lets you inject the shellcode automatically and handles the connect back or socket reuse.. well that gets you shell access, I guess that's what you mean by 'hack'. Just create a text file on his desktop that says "hi it's john jacob jingleheimer schmitt" or whatever your name is and you win the contest. If he's behind a software firewall or a NAT there's nothing you can do that I know of other than just intercepting his traffic, if that counts as a hack. You can sometimes do this on a wireless network by just passively listening ("promiscuous mode"). I guess if you waited for him to log into wikipedia (it still doesn't use secure login right? And anyway the login cookie's being sent in the clear) then you could show him his password and sort of win the contest. Apparently you can add http.cookie to your wireshark filters to get just HTTP requests with cookies, and then you can use one of many firefox extensions to import and use it. This can be a very educational excercise but don't get carried away and turn it into a negative experience.. .froth. (talk) 19:00, 4 February 2009 (UTC)

If it were a CS professor's assignment I'd say "have fun", but in this particular case I have to advise against the attempt. It would seem that the professor doesn't understand/realize exactly what he is suggesting, which would imply shaky consent at best. "Hacking" is probably against the code of conduct, and even if the professor accepts the results in good humor (including potential damage to his computer), the network administrators whose network you used to "attack" another computer might be significantly less understanding. – 74  19:18, 4 February 2009 (UTC)

Is it connected wirelessly? If so, it should be pretty easy to crack it by using a tool like Wireshark or Kismet. If it's a wired connection, try typing ipconfig /all inside a computer attached to the network to find your subnet mask. Then, you can try scanning all computers within the network (represented with a zero or two) with nmap or Nessus. You can also try typing net view to find his laptop. Let us know what the results of the nmap and Nessus scans are, and we'll be able to point you in the right direction. If that doesn't work, then just send him a virus inside your next assignment. ;) Just embed it into a Word document (as VBA) and use it to install Netcat.--K;;m5m k;;m5m (talk) 19:30, 4 February 2009 (UTC)

Thanks for the help. He is connected wirelessly, and I really like the idea of sending him a virus embedded in an assignment (he'd think that was clever, although I'm almost positive he'd catch it). I'll look up the software you've mentioned and hopefully the results of the scan will tell me something useful (with help deciphering, of course). I was also thinking that there's probably a way to do it using only the terminal/command prompt (I've heard of running commands on a local computer by giving yourself admin access) and that might be another thing to look into, if I could figure out how to do it. Thanks again. -Pete5x5 (talk) 20:56, 4 February 2009 (UTC)

You wrote "That just sits at the front of the room". If you have physical access to the PC, boot it with an Ophcrack CD. If the password is 14 characters or less, you're Administrator within half a minute. Then you can configure it however you like, add extra accounts etc, and later log in from the network. --NorwegianBlue ^talk 22:18, 4 February 2009 (UTC)

Try Metasploit. --wj32 ^t/c 05:05, 5 February 2009 (UTC)

You don't even need Ophcrack. Just reset the password using a bootable CD (there are plenty out there) --wj32 ^t/c 05:07, 5 February 2009 (UTC)

Yea, but there's nothing more l33t than to walk up and tell him his password. --76.167.241.45 (talk) 06:58, 5 February 2009 (UTC)

You could try humor - just email him this:

BAD NEWS:

You have just been infected with the Honor System Virus.

As it's name implies, this virus works by the honor system

please reboot your computer, delete three files at random

then forward this email to five of your friends.

Thank you.

<insert your name here>

SteveBaker (talk) 20:50, 5 February 2009 (UTC)

(Oh crap - now I've gone and infected half of the WP:RD staff...sorry - my bad!) SteveBaker (talk) 20:52, 5 February 2009 (UTC)

I'm safe: I use Linux :-) Carnildo (talk) 22:28, 5 February 2009 (UTC)

You can't delete your documents under linux? .froth. (talk) 18:25, 9 February 2009 (UTC)

Steve, Steve, Steve! You only made 1 grammatical mistake in that message - you need at least 4 per sentence, or it sounds totally unrealistic! :) - Jarry1250 ^{(t, c)} 22:00, 6 February 2009 (UTC)

Need Help with A Shell Script

Resolved

Hello wikipedians,

I've recently made the move to ubuntu, and have been loving it. One thing I miss tho, is being able to use VB Express to write my programs (I'll probably move on to C++ shortly). I need a quick fix to my programming needs tho, so I've come here lookin for help.

I have a big text file with lines consisting solely of ten digit numbers (file is close to 1gig in size). I need them "converted" into "file+path" thingy. What I mean is 1234567890 would be turned into a relative path 1\2\3\4\5\6\7\8\9\0.txt, with nothing in the actual text file (or maybe just a single space).

Thanks in Advance - PrinzPH (talk) 18:26, 4 February 2009 (UTC)

This thingy will do it: sed 's/\(.\)/\1\//g; s/$/.txt/; s/\/\././' < your_numbersfile | awk '{system("touch " $0)}'. If you regret/I misunderstood your question replace touch with rm. --194.197.235.61 (talk) 18:49, 4 February 2009 (UTC)

I thought you'd need something like 'mkdir -p path' to create the various subdirectories. Does 'touch' create the path in addition to the file? Anyway, the request seems rather odd; PrinzPH, would you be willing to elaborate on what you are trying to accomplish? – 74  19:00, 4 February 2009 (UTC)

The following Perl script will do what you want (the script above has problems). You might consider learning Bash, Perl or Python rather than C++ for VB-level tasks. C++ is *way* more difficult to get anything done with. --Sean 19:18, 4 February 2009 (UTC)

#!/usr/bin/perl -w

use File::Path;

while (<>)
{
    s/\s//g;
    my @nums = split '';
    next unless @nums == 10;
    my $filenum = pop @nums;
    my $dir = join '/', @nums;
    mkpath $dir;
    open F, "> $dir/$filenum.txt" or die $!;
    close F or die $!;
}

Oops, touch doesn't create directories. I'm sorry if there was any trouble. --194.197.235.61 (talk) 19:37, 4 February 2009 (UTC)

Thanks for the prompt responses. Btw, am I missing something? I can't seem to make out where the script sean was kind enough to give takes in input from the 'source' text file. Also, this is an experiment of mine. The text file is actually more like 2+ gigs (its the Do Not Call List), and I was considering ways of checking if a phone number was included. I was initially thinking of just using some form of database, but i thought that something like ' if exists('5/5/5/1/1/1/2/2/3/3.txt')' might have advantages. I was thinking using directories might save on disk usage too (a couple of bytes in a text file vs a 0byte directory/file). I dunno, I guess am just crazy ;) - PrinzPH (talk) 20:09, 4 February 2009 (UTC)

Sean's script reads input from stdin. Save it to a file, do chmod a+x scriptfile to give all users permissions to execute it, and then ./scriptfile < numbersfile to execute and pipe numbersfile to scripts input. --194.197.235.61 (talk) 20:29, 4 February 2009 (UTC)

(ec) The '<>' above is a little bit of Perl magic that reads input, either passed to the script via a '|' (cat foo | ./ex.pl) or from files added to the command line (./ex.pl foo). Your storage scheme will hide the disk space cost in directories (many, many directories) instead of the index file. This will be significantly less efficient for several reasons: 1.) directories will use more disk space total (file system overhead); 2.) the information will be spread out on the disk, resulting in longer access times; 3.) file systems were not intended to store information in this manner. A database makes much more sense in this case—this is a problem they were designed to solve, after all—and should provide close to optimal performance without "reinventing the wheel". – 74  20:32, 4 February 2009 (UTC)

A close-to-optimal solution to your problem would be to sort the file and then do a binary search on it:

sort do-not-call.txt > do-not-call-sorted.txt
look 5551112233 do-not-call-sorted.txt

--Sean 23:43, 4 February 2009 (UTC)

Thanks for all the feedback, I've learned from all the examples / reason you have given. I will go the database route. Thanks again! - PrinzPH (talk) 01:24, 5 February 2009 (UTC)

Keeping a hard drive in a fridge on a permanent baisis

Here's one that'll probably give you folks a laugh. I have a hard drive with frequent heat problems- ones I originally mistook for its total breakdown, but which I now understand are a transient if frequently-recurring problem. I have an ordinary mini-fridge within three feet of my computer- and, with a little experimentation, the hard drive can fit within indefinitely, with the door sealing capably around the cables and not pinching them. My question is if there's anything about this setup that could cause permanent damage to the drive- humidity within the fridge, for instance. -199.89.180.65 (talk) 20:53, 4 February 2009 (UTC)

There are hazards to over-chilling - the mechanical parts may become brittle and may actually decrease lifetime; thermal contraction may cause out-of-spec hard-drive head float distances; etc. I have never run a harddrive in a refrigerator, but I have run computers outdoors for extended periods of time in arctic winters, and as a general rule this is bad for device lifetime. Nimur (talk) 21:37, 4 February 2009 (UTC)

(ec) Overheating of the drive is probably an advanced sign of failure; I wouldn't put anything important on the drive. I don't have any experience with refrigerated disk drives, but I suspect the cold temperatures could have an adverse effect on the mechanical components, particularly during start-up. If the drive is worthless on its own then you might as well run it in the fridge (even if its lifetime is effectively reduced), just don't depend on it to store vital information. – 74  21:49, 4 February 2009 (UTC)

Why not just get a big fan and blow on it? --76.167.241.45 (talk) 05:23, 5 February 2009 (UTC)

A "mini fridge" is not that cold, is it? If you could set the temperature to, say, 10°C it might just work. I have no practical experience in this matter, though. --Andreas Rejbrand (talk) 08:45, 5 February 2009 (UTC)

...but, of course, the disk is surely designed to be operated at room temperature, so if it becomes overheated, there is a problem with it. Do not store the only copy of your latest novel on it. --Andreas Rejbrand (talk) 08:55, 5 February 2009 (UTC)

Fridges are actually very dry places - so once the drive has cooled down, humidity shouldn't be a problem. However when you take it out of the fridge, it will immediately come into contact with warm, humid air and water will condense onto it. That could possible ruin it. SteveBaker (talk) 20:31, 5 February 2009 (UTC)

You could possibly get a drop of water falling on it in a fridge, especially one with a defrost cycle. That is, frost can build up, and then melt during the defrost cycle, and drip. Normally they design a fridge not to do that, but they can screw up, of course. One drop of water could ruin a hard drive, so you might want to put something on the shelf over it, like aluminum foil, to prevent this. StuRat (talk) 21:03, 5 February 2009 (UTC)

Startup sound copyright

Are certain computer sound effects copyrighted? For example, the Windows XP start up sound, or the old Mac OS Chimes of Death sound. Would it be considered copyright infringed to used these examples in particular? --Randoman412 (talk) 23:16, 4 February 2009 (UTC)

I don't see why they shouldn't be copyrightable, but copyright law is shrouded in difficulties. What purpose did you intend to use them for? Algebraist 23:20, 4 February 2009 (UTC)

Yes, they are certainly copyrighted. I even recall reading an article once about the guy who made the Windows XP start up sound, though for the life of me I can't find it. As for infringement, that's a totally different determination—if they were, say, incidentally used in a movie that would almost certainly fall under "fair use". If you're remixing an entire sound around them, then it's a different determination. The fact that they are start up sounds (and not, say, music from a rock star) would certainly play into a court's assessment of whether it is "fair use" (nature of the work in question matters), but still, there's no blanket way to know yes or no. This is not legal advice, just a warning: could potentially be infringement, but might not be. Even a lawyer would only be able to tell you what they feel it is—only a judge would be able to really tell you one way or another (which is not a situation you want to be in). --98.217.14.211 (talk) 01:48, 5 February 2009 (UTC)

If you used the sounds on a computer they were installed on by playing the file, there would be no infringement issue. Graeme Bartlett (talk) 20:24, 5 February 2009 (UTC)

Remember that anything that CAN be copyrighted - automatically IS copyrighted. The author doesn't have to do or say anything special to make it so. Hence, for things like sounds, music, pictures, movies, software and text - your assumption should always be that it IS copyrighted unless there is something specificially saying that it's not. SteveBaker (talk) 20:28, 5 February 2009 (UTC)

Yes, you can pretty much assume that Microsoft doesn't release something under the Creative Commons ;) --BiT (talk) 13:11, 7 February 2009 (UTC)