Wikipedia:Reference desk/Archives/Computing/2009 November 20

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November 20

Designing my own simple computer language

Just how difficult would it be to design my own computer language? Is there a complier-compiler available that will churn out a compiler (or preferably an interpreter) if I give it a grammar in BNF for example? I would like to design a language that can do things with blocks of text, as described in questions above. Maths etc not needed. Would it be possible to find a freeware compiler for a simple version of BASIC written in Forth, for example, and modify it to my needs? Perhaps what I want to do is something like an old-fashioned macro-preprocessor. 92.27.154.180 (talk) 00:28, 20 November 2009 (UTC)

An interpreter is generally easier than a compiler (as you don't have to generate machine code or assembly language for a specific processor). Typically you need to parse the input program; it's common to use a parser generator to take some of the effort for that (they often take a BNF grammar and produce a parser for you). Which one you choose, and how you proceed from there, depends on what language you already know well). I doubt taking an existing interpreter would be the clearest path, but your mileage may vary. -- Finlay McWalter • Talk 00:37, 20 November 2009 (UTC)

Take a look at flex lexical analyser and GNU bison. (These are free alternatives to the original lex and yacc tools). Between these two tools, designing and implementing a new computer language is a fairly modest "textbook exercise." (In fact, I believe it is a textbook exercise in Patt & Patel, the best introductory computer systems textbook I ever used). There will be some ugly details, but if your language is well-defined (e.g. can be written in Backus–Naur Form), then the rest is just a matter of how much you want to polish the product. Nimur (talk) 03:09, 20 November 2009 (UTC)

The other suggestions here are great - but just as an aside, I've developed my own languages a few times, (most recently as a teaching language), and using an interpreter is, indeed, much easier and very quick to throw together. A simple Turing-complete language, with dynamic typing and a fairly flexible syntax, isn't that hard to do. That said, I'd lean towards looking for a pre-existing language first, as the big problem will be in efficiency. It's fairly easy to throw together an interpreter, but it is relatively difficult to throw together an interpreter that runs well. :) Perhaps something like Perl will do what you want (when people mention blocks of text I think Perl, but maybe that's just me). - Bilby (talk) 12:34, 20 November 2009 (UTC)

Perhaps a Template processor or something related to it is what I am seeking. Chances are there is already a language out there that can do what I want, if I can find it. The essential thing is to be able to deal with blocks of text (such as paragraphs or even pages) rather than just lines. 78.151.128.59 (talk) 12:25, 20 November 2009 (UTC)

This looks like more of a representation problem. How would you represent pagination in normal text? Via markup or via a form-feed character? If your format is well-defined, any scripting language will do. I'm partial to Python, but AWK and Perl would serve just as well. If, on the other hand, when talking about "text" you mean a heavily formatted opaque format like MS-Word files, you are in for a lot of hurt - but that will not go away with your own language. --Stephan Schulz (talk) 12:52, 20 November 2009 (UTC)

I prefer just simple plain text files. A paragraph has a blank line (ie two carriage-returns) above and below it. A page has a page-break character above and below it. Or the start or end of the file as appropriate. I did not think AWK could deal with blocks of text, only lines? Perhaps Perl etc could do what I want, but its hidden by a lot of other stuff that I don't want to use. 78.151.128.59 (talk) 13:06, 20 November 2009 (UTC)

For GAWK you can define what constitutes a "line" by assigning a proper regexp to RS (the "record separator"), e.g. gawk 'BEGIN{RS="\n\n"}{print "Para: " FNR "\n"; print $0 "\n"}' [your input file]. For Python, you can just read the whole text and split pages on one regexp for pages, and on another for paragraphs. Of course you need to decide what you want to do if a paragraph is on two pages... --Stephan Schulz (talk) 13:25, 20 November 2009 (UTC)

If you're just writing a compiler to educate yourself, then good for you. If you're really doing it because you think it will be less effort for doing the simple things you want to do than just learning any of the many general purpose languages that can do them, you're fooling yourself. Look at Stephan's last post there: it can do everything you've described, in a line or two of code. The source code to even the simplest compilers is not a line or two. --Sean 14:49, 20 November 2009 (UTC)

Indeed. I wrote a simple C-like scripting language interpreter (PSL - a part of my PLIB library) a while back - I just checked and the compiler/interpreter came out at 5,365 lines of C++ code. You can do an awful lot of fancy text processing with 5,300 lines of code in almost any language! So, yes - designing and implementing your own language is interesting and quite instructive - but it's hardly ever productive as a way to solve a problem.

As for "compiler-compilers" - there are syntax generators (eg yacc/bison) and parser generators (eg lex/flex) - which certainly handle the parsing of the source code - but don't help much with building parse trees, generating some sort of byte-code and then interpreting that code. I've used yacc and lex many times in the past - but for PSL, I wanted to simplify the build process - so I decided to write the parser in C++ code. The parser went together very smoothely - I believe my parser was easier to generate in C++ than in yacc/lex - and it's vastly simpler and faster than a yacc/lex-generated parser. Yacc and Lex are also a pain to deal with in large projects - it's difficult to build a project with more than one yacc/lex parser for example. I honestly believe that compiler/compilers are overrated. SteveBaker (talk) 20:35, 21 November 2009 (UTC)

Google cache

Whenever Google updates it's cache of a website, does the previous version of the cache get overwritten? If not, how can a previous version of Google's cache be accessed? -- penubag  (talk) 01:08, 20 November 2009 (UTC)

I don't think you can get old versions from Google cache. Try archive.org. --Tango (talk) 11:19, 20 November 2009 (UTC)

Netbook performance

I'm really interested in this whole netbook thing, but am left with questions regarding their actual performance. Would most netbooks be able to handle running an XAMPP instance along with an IDE like PHPEdit or Netbeans and an open browser? Or would that max out the current average hardware setup available? 218.25.32.210 (talk) 02:37, 20 November 2009 (UTC)

My Lenovo IdeaPad S10e has a dual-core Intel Atom, and I have used it to run ("toy-problem"-size) parallel processing jobs, compile FORTRAN-90, operate a Java IDE (Eclipse (IDE)), as well as to compile and synthesize FPGA firmware, run 3D SolidWorks modeling, and operate a webserver. I have done some of these tasks simultaneously. The two things which seem to tax the processor are 3D rendering and Adobe Flash Player 10. The first, I accredit to the lack of much video RAM (I think up to 128MB, but shared video RAM and an Intel Mobile graphics accelerator); the latter, I attribute to Adobe Flash Player 10 being a truly horrible piece of software. Nimur (talk) 03:19, 20 November 2009 (UTC)

Toolbar disappeared

Help. My toolbar (if thats the correct name for it) has suddenly vanished - the gray bar across the top of a window that says file, edit ... tools etc. Instead there's a dark blue bar across the top with an e in lighter blue with a gold ring on it which does nothing, then a gray bar with the address, refresh and google search stuff, then another gray bar with a star which does nothing and a W. How can I get back to normal? —Preceding unsigned comment added by 98.64.88.193 (talk) 04:13, 20 November 2009 (UTC)

Which operating system? Which program is missing its toolbar? You need to provide more details to get any kind of sensible answer. Astronaut (talk) 07:33, 20 November 2009 (UTC)

Microsoft Windows XP, Media Center Edition, Version 2002, Service Pack 3. This information hasn't changed since I had my old top of the screen. The new dark blue and gray top is on all internet screens. Thanks for replying. —Preceding unsigned comment added by 98.64.88.193 (talk) 08:13, 20 November 2009 (UTC)

So Internet Explorer on Windows XP. Sounds like it has gone into full-screen mode, or some/all of the Internet Explorer toolbars have been hidden.

First try pressing F11 and see if it all comes back. If not try to right-click in the grey bar between the "star" and the "W" and see if a menu comes up with ticks next to things like "address bar" and "status bar". If that menu appears and there is no tick next to "menu bar", then click the "menu bar" option. Astronaut (talk) 09:13, 20 November 2009 (UTC)

Hi Astronaut. Thanks for writing. I tried F11 and the whole gray and blue top disappeared, so I had nothing. I tried right-clicking on each level and the only thing I got was a small box which said " Restore to smaller screen (in light gray, not useable) Move, Size, _ Minimize, X Close Alt + F4." By looking at my ADD and REMOVE PROGRAMS I saw that I have Windows Internet Explorer 8 with five updates and Microsoft .NET Framework 3.5 SP1 with 3 updates. I tried removing Explorer 8 and it gave me all kinds of warnings that many programs might not work properly if I did that. The first time I quit, but I get so much grief (for example Task Manager is terrible) that I went back and removed Explorer 8 and let the chips fall where they may. Well I got into a terrible loop as soon as I got back from restart which seemed to come from my registry so I was able to restore back to being stuck with Explorer 8. Besides, that might not even be the problem, since this blue top has only been around for a day or two and I got Explorer 8 in October. I tried removing two recent non-security updates but it didn't make any difference. Please help. —Preceding unsigned comment added by 98.77.181.227 (talk) 15:28, 20 November 2009 (UTC)

Try pressing "Alt" and see if you get the menus and then follow Astronaut's instructions for checking Address bar and status bar.--TParis00ap (talk) 18:55, 20 November 2009 (UTC)

I pressed Alt and nothing happened, no difference. —Preceding unsigned comment added by 74.233.227.101 (talk) 20:02, 20 November 2009 (UTC)

Try pressing F10, then clicking View, Toolbars, Menu Bar. --Bavi H (talk) 02:12, 21 November 2009 (UTC)

The bar across the top which normally says "File Edit View Favoirtes Tools Help" is missing. There is no "View" but thanks for replying. I pressed F10, and all the other Fs - nothing happens except with F11 I gain and lose what bars I have. On the right of the "W" bar is a blank gray square which, when I click on it gives me a new blank screen on top of what I doing, and a small square between the star and the "W" which has four even smaller boxes in it which, when I click on them enables me to switch from one window to the other. When I first got Explorer 8 I could get up to seven bars across the top and the toolbar was one of the bars which I could uncheck. Therefore I think this problem might have something to do with Explorer 8. ALSO it only happens when I'm on the internet, when I'm looking at something within my PC I get the normal toolbar. —Preceding unsigned comment added by 98.77.193.59 (talk) 17:34, 21 November 2009 (UTC)

OK, now I'm a little baffled. You seem to be describing the situation similar to this image, with the menu bar missing. If that is the case, pressing F10 should make it reappear temporarily so you can choose the "view" menu. Alternatively, you could try right-clicking on one of the areas I have highlighted in this annotated image to make a pop-up menu appear, and making sure there's a tick next to "menu bar". Unfortunately, I don't have a "W" bar and have no idea what that might be.

Can produce a screenshot (press alt-print screen and paste into your favourite image editing program) of what you have now in IE8. It would be really useful to upload it to somewhere like imageshack or photobucket, and put a link here so we can all see what's up.

Failing that, you could always try repairing your Windows XP installation. To do that you will need to boot the PC from the XP installation disk (you probably got one when you bought the PC), and choose the Repair option. Astronaut (talk) 18:49, 21 November 2009 (UTC)

Ah! This image is what I mean by the pop-up menu that lets you put a tick next to "menu bar". To get this I simply right-clicked where the top left of the menu is. Astronaut (talk) 19:00, 21 November 2009 (UTC)

WOW Thanks for telling me about imageshack, it's really interesting and useful. I took a printscreen of this page as I see it and saved it by paint>edit>paste>save and here it is: this image I hope you can see it. As you can see I don't have the pink areas and all the other things which you have, and no F key makes any difference except F11 makes the whole top disappear and clicking on the square gray box gives me another, blank screen and a little box between the star and the W which I can use to switch from one of my screens to the other. —Preceding unsigned comment added by 98.77.193.59 (talk) 20:40, 21 November 2009 (UTC) Here I used the other window to switch from here to imageshack, took a printscreen and uploaded it so you could see it here. This is about all I can do now - I can't print, save, create an icon, save in favorites, have any tools etc. Here's the second page

Ummm, do you really not get the pop-up menu if you right-click in the areas I have shaded pink in this image? The missing text is also worrying - the title bar (ie. the "blue bar") should have text that is created by the website, probably something like "Wikipedia:Reference desk/Computing"; the gold star should be followed by the word "Favorites"; and the "W bar" (actually called a "tab", with the "W" icon from Wikipedia) should have the same text as the title. However, the missing text could be a feature of your choice to use the "classic windows theme" in XP. I would probably try the repair installation next. Astronaut (talk) 15:16, 22 November 2009 (UTC)

1)My Default Internet Browser is Version 810.6001.18702 What's yours? 2)I tried changing the themes to all others and the appearance to all others, the effects from all checked to all blank and the advanced within appearance from desktop to active title bar. All changes made no difference at all. 3)My operating system CD says "Only use this DVD to reinstall the operating system on a Dell PC", nothing about having an option for repairing. —Preceding unsigned comment added by 74.233.41.226 (talk) 21:59, 22 November 2009 (UTC)

Did you try to get the pop-up menu to appear?

My IE8 is 8.0.6001.18828. 810.... seems a litle suspicious to me but I do have several updates pending. The Install disk does have an option to repair, certainly on Dells - only the other week I fixed my sister's Dell Dimension and saw the repair option (her problem was much more serious and I has to reinstall XP). Here is a page from Microsoft about doing a repair install, or you can read this page with its pretty pictures showing you what to expect. read the instructions carefully - it is easy to get this wrong and have it wipe all your documents, photos, music, emails, etc. Astronaut (talk) 00:01, 23 November 2009 (UTC)

The only pop-ups I get are "Move, Size, Minimize, Maximize, X Close Alt+F4" when I right click on the top blue bar and "Cut, Copy, Delete, Open IME" when I right click on the address bar. That 810 should have read 8.0 (sorry - typo) but I'm more interested in the 18702 vs. 18828. I'm really curious - when you go to that About.com>Computer Problems Solved what place do you see Besser Computer comming from? I don't think I see the same place as you do. And I really don't think it's a matter of repairing Windows XP, that seems to be an extreemly drastic and risky measure for such a small problem. I did a registry scan recently and of course it found a zillion errors in my registry, which for free it would clean about five and for $$$$ it would clean the rest. I didn't even clean the five and deleted it but it keeps coming back. It's called Advanced Registry Optimizer. Do you know anything about it, and could it have anything to do with this? I think this is a bug in Explorer 8.

Sometimes you have to take drastic measures to fix a problem. Really, at this stage the repair installation option is probably your best bet. As a safety measure, it is a good idea to back up all your documents, photos, music, emails, etc.

While it seems to be a simple case of a missing menu bar, if you can't get the menu to appear through the methods described above then I'm out of ideas. You can poke around in the registry if you wish, but you have a much greater risk of making your PC refuse to work at all, than fixing this specific problem.

As for About.com, I very rarely use that site and cannot find the thing you mention. However, this Google search shows Besser Computer to be a computer repairers in Boca Raton, FL. I've never heard of them and they are about 4,500 miles from me. If your browser is directing you elsewhere, that is a usual sign of a malware infection.

I've never heard of it, but Advanced Registry Optimizer seems like a genuine program. Remember that the authors would prefer you buy their program, so it is in their interest to have it find lots of "problems" and then only fix a few for free. That said, I would be suspicious of anything that finds zillions of registry errors without explaining the impact of each. More so that when you decide to delete it, it keeps coming back with nagging sales messages and tenaciously hangs on in your PC despite attepmts to uninstall. Astronaut (talk) 02:52, 25 November 2009 (UTC)

C download

Hi,

I got new computer and I want to install C/C++ on it, where can I download it for free (if possible at all).--Gilisa (talk) 09:16, 20 November 2009 (UTC)

Free C/C++ Compilers and Interpreter

GCC, the GNU Compiler Collection

Your favourite search engine will probably find more. Mitch Ames (talk) 09:36, 20 November 2009 (UTC)

Are you sure you want to be programming in C or C++? Please don't take offense at this assumption I'm making, but the word usage in your post makes it sound like you're relatively new to programming. C and C++ are not at all for beginners. They're meant for interacting with the system at its deepest level. They're not easy languages to learn, and there's also a lot of other things you have to learn about before you can successfully write programs with them. If you just want to be able to dive into programming -- for example, to write a program and then run it -- a higher-level language such as Python may be a better choice.

Now, if you do plan to write C/C++ programs, you haven't said the most important thing, which is what operating system your new computer is running. I'll start with the easy one: if it's a Mac, you should get out the "Developer" CD that came with the computer and install Xcode. If it's Linux -- well, it's probably not Linux, but if it were, you'd have most of what you need set up already. If it's Windows, you can learn to use Cygwin so that you can write and compile C code using gcc and other free software, or you can use whatever Microsoft's free version of Visual C++ is. Just keep in mind that they'll probably be trying to gouge you for money later when you want to do something more complex. rspεεr (talk) 09:49, 20 November 2009 (UTC)

Under windows, there's Microsoft's own Visual Studio Express editons. Astronaut (talk) 09:53, 20 November 2009 (UTC)

rspεεr, you made a hell of assumptions based on the wording I choosed (but with good and appreciated intention). I know the difference between the two, anyway, each of both is good for my needs (which are not big and anyway, everything can be done with C can be also done with C++...). As you guessed, it's not linux -it's Windows XP and I already found what I need. Thanks to all who helped.--Gilisa (talk) 10:48, 20 November 2009 (UTC)

Technically, C and C++ are not for "interacting with the system at its deepest level". Most modern operating systems are written in C and C++, and the APIs they provide are in C and/or C++, but a fair amount of the principal core of the operating system is often written in assembly language, or in assembly language embedded in C or C++. And other than that, the dialects of C and C++ the operating system provides as an API usually has a heavy amount of system-specific extensions. Standard C and C++ abstract away a fair deal of stuff, and newcomers to the languages are usually surprised how far away from the physical machine the languages are - they tend to think that if their own personal operating system includes a C API to do something, then that feature is part of C itself. Nevertheless, out of modern production languages, C and C++ are usually as close to the physical machine as you need to go, unless you're actually developing your own operating system or your own device drivers. Programming directly in assembly language might bypass some of the code already written in the operating system or device drivers, and if that code is actually better written than your own, it might hinder the performance instead of helping it. JIP | Talk 20:52, 23 November 2009 (UTC)

OCR software that supports Japanese

Is there software (preferably free) than can take an existing image, scan it and extract the text on it - even if that text is in other languages including Japanese (it doesn't have to something fancy like translate the text into English). Astronaut (talk) 09:58, 20 November 2009 (UTC)

And your OS is . . . ? -- Hoary (talk) 10:16, 20 November 2009 (UTC)

Sorry, forgot. Windows Vista and various shades of Linux. Astronaut (talk) 10:20, 20 November 2009 (UTC)

It would seem to me Optical character recognition#OCR software combined with Optical character recognition#OCR software language support would provide a decent answer to your question. Is there any reason it did not? Nil Einne (talk) 10:30, 20 November 2009 (UTC)

Note that OCR for kanji, which has a symbol for each word, is unlikely to work well, as the probability of being able to recognize the correct symbol out of 50,000-100,000 is very low. On the other hand, recognizing katakana, where there's a symbol for each syllable, is far easier, as it reduces the list of possible symbols to around 51. StuRat (talk) 17:03, 21 November 2009 (UTC)

Bandwidth of Video

1. What is the bandwidth of the video signal from computer to the monitor? My monitor is a CRT with the connector to CPU having typical blue colour and three pin rows. I did something like (1024*768(Pixels)) * (3(RGB) * 8(bit)) * 60(fps) and got a really crazy number 1Ghz!
2. What is the name of that cable (standard used)? 59.93.13.187 (talk) 15:36, 20 November 2009 (UTC)

The cable is a VGA cable if it has three rows of pins, and the connector is a DE15. If it has a T-shape on one side, then it's a DVI cable. Bandwidth would be measured in bits/second in DVI, and is around 4Gb/s. VGA connections don't have a measured bandwidth since they are analog, but your monitor would be measured as 1024x768@60Hz. Assuming 8 bit color, the digital version of your resolution is 360Mb/s. 206.131.39.6 (talk) 17:06, 20 November 2009 (UTC)

It sounded like they said 24 bit color, in which case it would indeed be right around 1080Mb/s (or approximately 1Ghz). So, his numbers were right on the money. StuRat (talk) 18:18, 20 November 2009 (UTC)

I missed the 3*RGB that I forgot to factor into my calculations. In that case, it would be correct to say 1GHz 206.131.39.6 (talk) 18:36, 20 November 2009 (UTC)

Thanks for the clarification. Was doing a problem in information theory just after microwave and radar examination and when I saw such numbers, (rigid) waveguides came to my mind and so I thought I might ask here just to clarify. My processor is working at just 1.7GHz so how can it keep rendering at such high frame rates even with graphics card since it has to generate the data to send to the graphics card? 59.93.11.91 (talk) 15:41, 21 November 2009 (UTC)

It only sends very simplified data to the graphics processor, like "draw a white line from (x1,y1) to (x2,y2) and keep it there". The graphics processor then calculates the pixels to send in each frame, and that's where the heavy work lies. StuRat (talk) 16:48, 21 November 2009 (UTC)

EULAs

Hello, I was just wondering whether or not EULAs (End User License Agreements) are legally binding. I was having an argument about it the other day, and would like to get an answer. Thanks! Rootusercyclone (talk) 15:38, 20 November 2009 (UTC)

I just looked at Software license agreement, from which it seems that it depends upon the court jurisdiction, upon how the license is presented, and upon whether a customer needs to accept the license in some way before installing the software. Software license agreement#Shrink-wrap and click-wrap licenses includes examples of specific court cases. Tckma (talk) 16:15, 20 November 2009 (UTC)

It should be noted that EULAs and such are stupendously recent inventions (compared to the rest of contract law, which dates back to, you know, the Roman Empire), and exactly what is allowed to be put in there, what legal binding they have, and so on has yet to be properly hashed out. It's going to take courts years (maybe even decades) to properly get a grip the legal foundations of those dastardly things. Belisarius (talk) 16:06, 21 November 2009 (UTC)

Is this the long version of don't worry 'bout 'em? --Ouro (blah blah) 12:39, 22 November 2009 (UTC)

Here is an article on a recent court case involving Apple and a Hackintosh maker. --Joe^Talk_Work 00:09, 23 November 2009 (UTC)

I just read the decision. It's extremely frustrating in that it seems to assume (on pages 11–12) that Apple's EULA is valid without making that assumption explicit anywhere; it's like the judge isn't even aware of the controversy surrounding EULAs. The legal principle behind EULAs is essentially that first-sale rights don't apply to software. That would be a major expansion of the power of copyright, and there's nothing in the legal code to support it, so it's not the kind of thing that you just assume without comment. Very strange. I hope this decision will be ignored (as precedent). -- BenRG (talk) 01:59, 23 November 2009 (UTC)

Dreamweb

I am sorry for the double post but I am really desperate here, There is a game called Dreamweb that is from the mid 90's, I am desperate to play it again, I can download it, and I can install it but I canmt get it to run, there is no .exe file. Please, if any one can help me in anyway with this I would be eternally greatful Zionist —Preceding unsigned comment added by 62.172.59.90 (talk) 16:00, 20 November 2009 (UTC)

If it is from the mid-90s, it could be a DOS or Windows 3.2 file which could be .BAT or .COM file. I am not sure it'll run in later operating systems though.--TParis00ap (talk) 18:46, 20 November 2009 (UTC)

Our article, Dreamweb, may be useful. Also take a look at DosBox. Nimur (talk) 08:48, 21 November 2009 (UTC)

Tying special key on laptop to a script for closing programs

There is a button on my ASUS 5738Z which does something with the graphics card such that it uses less power. Is there some way that I can maintain this functionality while triggering some script to close programs that aren't necessary? I'm running Windows Vista. I downloaded this scancode program: http://www.brothersoft.com/scancode-download-199761.html but it does not respond to the special keys (e.g. this energy-saver key, the bluetooth-disable key etc) on my keyboard. Also, how would I write such a script in Windows (what would be the simplest way)? ----Seans Potato Business 18:37, 20 November 2009 (UTC)

I use AutoHotkey for scripting. F (talk) 04:22, 21 November 2009 (UTC)

How would you decide which programs "aren't necessary"? Astronaut (talk) 19:04, 21 November 2009 (UTC)

I will just use my own judgement: e.g. Logitech Webcam utility = not necessary. ----Seans Potato Business 16:19, 23 November 2009 (UTC)

You can manage power settings from the command prompt using the powercfg command. You'd type this code into a file in Notepad, save it with a .bat extension, copy it, right-click on the start menu, choose Explore All Users, then right-click in the Start Menu folder and choose Paste Shortcut. Then, you'd right-click on the shortcut and choose Properties, and then select a short-cut key combination. I do this to create all kinds of short cuts, like opening Internet Explorer or Outlook. Here's the code:

@echo off
powercfg /setactive "Max Battery"

As for shutting down programs, you could create another batch file. If I wanted to shut down spoolsv.exe, for example, I would type this into a file:

@echo off
taskkill /f /im spoolsv.exe

It think the taskkill command is only available in Windows Vista Business and Ultimate, though. If you're using another version, then we can use VBScript or JavaScript to automate the shutdown.--Drknkn (talk) 19:41, 21 November 2009 (UTC)

Hi; thanks for your response. I'm using Vista Home Premium. Is there a command less heavy-handed than taskkill? I would like programs to have the time needed to save data etc before closing, even if they have to prompt me to save/discard/cancel. Do VBScript/JavaScript allow such "gentle"--Seans Potato Business 16:19, 23 November 2009 (UTC) closing of programs?

Not a problem. If you remove the /f from taskkill it will ask you to save any unsaved documents, first. If you don't have that command, you can download it here: [1]. You'd then save the file into your Windows directory. You can also use VBScript, like this, but it'd be an abrupt shutdown:

strComputer = "."
Set objWMIService = GetObject("winmgmts:" _
    & "{impersonationLevel=impersonate}!\\" & strComputer & "\root\cimv2")

Set colProcessList = objWMIService.ExecQuery _
    ("Select * from Win32_Process Where Name = 'Notepad.exe'")

For Each objProcess in colProcessList
    objProcess.Terminate()
Next

To use the VBScript, you'd save the code into a file with a .vbs extension and then double-click on the file. You can replace the Notepad.exe text above with the file name for any other file you want to terminate.--Drknkn (talk) 16:54, 23 November 2009 (UTC)

With gray rectangles, the arrow keys don't work

Most library computers I use now have blue rectangles at the bottom of the screen and a green start button. Today, I was using a computer with Firefox that had gray rectangles at the bottom of the screen and a gray start button. Whenever I would use the actual down arrow, it would go right to the bottom of the page. The up arrow would return me to the top. To go anywhere on the page, I had to use the mouse and the up or down arrow on the screen, which I find annoying.Vchimpanzee · talk · contributions · 19:43, 20 November 2009 (UTC)

There are a variety of reasons why a library or public computer might override the default user interface. Take a look at our article on kiosk software. Sometimes, the intended goal is not realized very well (it sounds like the keyboard interface in your example has been tweaked with unintuitive results). Your best bet may be to contact the technical support or the computer/IT librarian directly - they have a better chance of knowing what customized interface they are using; and you might be providing helpful feedback to them about ease of use. Remember that they have many users besides you, so your convenience isn't the only consideration for them; but if your feedback is worded diplomatically, it might have an impact when they roll out the next software version. Nimur (talk) 08:16, 21 November 2009 (UTC)

Also look into using the PageUp and PageDown keys. Other users may have customized the various function keys into a manner which others (including yourself) find annoying, but PgUp and PgDn usually keep their intended function. --DaHorsesMouth (talk) 22:15, 21 November 2009 (UTC)

Keeping more digits in Excel

If you expand a cell in MS Excel and type in a really long number like 1234567890987654321, Excel will automatically round it to 1234567890987650000. That's if you're left enough space, of course; it gives it to you in scientific notation if you don't. Is there a setting to change to force Excel to keep more digits? Failing that, is there another spreadsheet-style program that would? I'm using Excel 2002 in Xp and Excel 2007 in Windows Server 2003.

The numbers are handled internally in scientific notation, and the rounding that you see is because the computer floating-point hardware has a limited number of digits of precision (see IEEE 754-2008). Arbitrary-precision arithmetic software exists, but it is slower. --Jc3s5h (talk) 21:55, 20 November 2009 (UTC)

Having to cope with Zimbabwean dollars are you? I don't know of any spreadsheet program that does what you want and I doubt there is any. There are simple calculator programs around though that will work with more digits if you just want to do something small. Perhaps if you describe the problem a little more someone might have a better solution. Dmcq (talk) 10:17, 21 November 2009 (UTC)

I was just playing around with the patterns you get when you multiply increasing larger numbers with themselves; nothing serious. I made a series of numbers in the A column that went 2, 22, 222, 2222, and so on for something like 15 iterations. Then I created a series of formulae in the B column, so that I was multiplying 2x2, 22x22, 222x222, etc. They make for an interesting pattern (no the one given) until you get far enough and the rounding comes into play. I was hoping there was a spreadsheet-style program that would allow me to go further as I wanted to see how the pattern developed (calculator programs generally only give you one answer at a time :-). When I noticed the rounding, I started just entering large numbers to see if it was an arithmetical shortcoming or just a limitation on the number of digits - obviously the latter. As I say, it was just idle curiosity. If there was a setting to change somewhere, I would do it, but there's not, so I'll move on with my life somehow :). Matt Deres (talk) 13:39, 21 November 2009 (UTC) (OP, who apparently didn't sign his question)

This is when it's nice to have a proper programming language or (even better) a real Computer algebra system around. This is a conversation I just had with my Python interpreter:

2,22,222,2222,...

>>> rows = 15
>>> a = [int("2" * n) for n in range(1,rows+1)]
>>> b = [n * n for n in a]
>>> for i in range(len(a)):
...     print a[i], b[i]
...
2 4
22 484
222 49284
2222 4937284
22222 493817284
222222 49382617284
2222222 4938270617284
22222222 493827150617284
222222222 49382715950617284
2222222222 4938271603950617284
22222222222 493827160483950617284
222222222222 49382716049283950617284
2222222222222 4938271604937283950617284
22222222222222 493827160493817283950617284
222222222222222 49382716049382617283950617284

As Jc3s5h alluded to, the issue here is that internally, computers represent large numbers in a floating point format, roughly analogous to our human scientific notation. By necessity, this means that when the numbers lose some precision and become a little fuzzy around the edges when they are very large (if you're interested in the nitty-gritty of how the numbers are stored, I recommend the article Single precision floating-point format, which has a very nice diagram and some examples). And as Jc3s5h correctly stated, if you absolutely positively need the exact number, Arbitrary-precision arithmetic is the way to go, but you either need to learn a computer language to do that, or install a Computer Algebra System (Maxima is free and does the job very nicely). Though moving on with your life sounds like a better alternative :) Belisarius (talk) 16:02, 21 November 2009 (UTC)

As a stop-gap, if you try dividing your number by say, 2, 3 and 7, and then saving both factors - for example 21*123456787654321. Then, replace uses of say A1 with A1*B1. That way, you might keep the accuracy (I'm not sure). - Jarry1250 ^{[Humorous? Discuss.]} 10:28, 21 November 2009 (UTC)

I can thoroughly recommend Python if you're doing things like this on an occasional basis. It is good for a lot of other tasks you might think of besides as well. Dmcq (talk) 18:29, 21 November 2009 (UTC)

The specific example our OP gives has 16 digits of precision - and that is (essentially) the upper limit for double-precision floating point arithmetic. That's the most precision that the computer can perform operations on using it's built-in hardware logic. To make a human analogy - doing more precision than 16 digits that requires it to do something akin to "long multiplication" and "long division" - numbers under 16 digits is something the computer can do using "mental arithmetic" alone. It's certainly possible to write software to handle much more precision (the 'bc' calculator program under Linux/UNIX can do that, for example) - but it's very slow compared to 16 'double precision' floating point. Since there are very VERY few situations in the real world that demand more than 16 digits, it's not worth slowing down the performance of a spreadsheet program to accommodate the needs of so few users. Almost all programming languages and almost all application programs have the same inherent limitations - simply because it matches the precision of the computer hardware. If you need arbitary precision arithmetic - you could install the "Cygwin" package for windows and use the cygwin command line tool to run the 'bc' calculator program:

     steve@gnosis:~> bc
     bc 1.06
     Copyright 1991-1994, 1997, 1998, 2000 Free Software Foundation, Inc.
     This is free software with ABSOLUTELY NO WARRANTY.
     For details type `warranty'.

     1234567890987654321 + 1
     1234567890987654322

Tadaaaa! SteveBaker (talk) 19:44, 21 November 2009 (UTC)

Help deleting this folder

I have a folder on my desktop called "Perforce" and I can't delete it. Every time I try it gives the message "Could not find this item. This is no longer located in C:\Users\Jeska\Desktop. Verify the items location and try again". I've restated the computer three times now, and no programs are using this folder. How can I delete it? Windows 7 btw

Help Transferring Files

I have a hard drive that was removed from a computer and I want to put the files on it onto my new computer. Does anyone know if any big electronics stores like Best Buy, would do it. Thanks in advance!

Americanfreedom (talk) 23:40, 20 November 2009 (UTC)

If you are referring to the files and only the files, there is no reason they won't. It is very trivial. Plug in the extra drive. Turn on the computer. Drag/drop the files. Turn off the computer. Remove the extra drive. However, if you want them to reinstall all the programs you had installed on the old drive, that isn't going to happen. You have to reinstall from the install disks. -- kainaw™ 23:44, 20 November 2009 (UTC)

Thanks, I tried that at home but it wouldn't plug into my computer or his. Do you know how much asking Best Buy to transfer files would run me?

Americanfreedom (talk) 17:02, 21 November 2009 (UTC)

I don't know the exact price, but it'll be somewhere between 10-20 times as expensive as it's worth. Most people know a kid/nephew/niece who's opened a computer before and installed parts. It's not that hard to do and I'm sure giving someone $50 would be a great deal for most people, but probably 1/4 the price of best buy. Short version: Best buy is WAY to expensive for something this simple, look for a more local option. Chris M. (talk) 19:05, 23 November 2009 (UTC)

You can buy an external drive case quite cheaply that has a USB socket. Unfortunately the one I have in front of me does not have any brand-name on it. 92.24.40.108 (talk) 11:11, 24 November 2009 (UTC)