Wikipedia:Reference desk/Archives/Computing/2007 July 19

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July 19

Way to tell age of an AIM account?

Hey, I was asked earlier how long I've had my AIM account for, and I honestly can't remember. I seem to remember there being a date somewhere on accounts that showed you how long they had been using AIM, but I can't seem to find it. Any help with this? Or will I have to mail AOL and ask if they know? --L^augh! 02:10, 19 July 2007 (UTC)

When I check info on an AIM account in Pidgin (software), it shows me when the account was activated. -- Kainaw^(what?) 02:14, 19 July 2007 (UTC)

Ok, I had to use "get info" and put in my own username, it wasn't on the right click menu. GAIM Forevar! --L^augh! 02:20, 19 July 2007 (UTC)

do iPods know what color they are?

I just noticed that in both iTunes and the Finder, the icon for my (blue) Nano is... blue. With any other company I'd unhesitatingly assume this was just a lucky coincidence, but with Apple... well, that's just the sort of neat hack they'd actually pull.

Does anybody reading this have a different-color Nano to confirm whether its icon is blue, or the right color? —Steve Summit (talk) 04:11, 19 July 2007 (UTC)

They do. My black nano appears black. It has something to do with the serial number.

If you see the Uncyclopedia page about how to attach a 20GB SATA Hard drive to an iPod Nano it says that it can only be done on the black ones because of a different type of connection, which suggests that they have different hardware too.Mix Lord 23:27, 19 July 2007 (UTC)

In case someone doesn't know what Uncyclopedia is, take a look at its article here. --cesarb 09:51, 20 July 2007 (UTC)

Right now (well, at least, "last time I looked"), of course, the black Nanos are also the only ones with an 8GB Flash ROM; the other colors are all 4GB units.

Atlant 11:54, 20 July 2007 (UTC)

Thunderbird and IMAP

Is there an option/extension/whatever so that IMAP will not perform all its changes offline and then sync them up to the server on quitting? Or is this something fundamental to the IMAP protocol?

Yes, it's really pretty fundamental to the IMAP protocol. Thunderbird does have (now built in, used to be an extension) the capability for making a folder available offline (right-click on folder, properties, offline, select this folder for offline use. In this mode (when you're offline) you can do stuff like moving mails around and deletw them - but I've found this to be unreliable, at least once rendering a folder into a permanently broken state. Tbird isn't a great IMAP client; but I don't know of a better one. -- Finlay McWalter | Talk 10:32, 19 July 2007 (UTC)

I presume Tb maintains a connection to the IMAP server until the user quits: is it possible to convince Tb in some way to close the connection quicker? (perhaps we're going outside the scope of the refdesk here).

What I am doing is migrating across mail clients -- I want to use Tb's filtering and spam filtering and use the other client as well, but it's becoming tedious to quit and restart Tb every time some new mail arrives that needs to be filtered. Thanks for your response, regardless.

I think what you're trying to do should work already, without offlining; I've certainly had two tbird clients open on the same inbox, and when one saw new mail it ran the spam filter over it and deleted the spam - the second client saw the new mail arrive, and then saw the other client delete it. IMAP is, in essence, a (rather specialised) network filesystem protocol. If your other IMAP client isn't seeing the changes tbird does automatically, I guess it's not a very good IMAP client (hopefully one that you're migrating away from, not toward). -- Finlay McWalter | Talk 22:39, 19 July 2007 (UTC)

You might cringe. It's the IMAP backend to Lotus Notes.

I don't intend to use the Tb multiclient solution for long, just as a temporary thing.

cant use bit torrent

im not able to use bit torrent in my LAN.. how do i download movies using bit torrent..??Yohann paul 06:44, 19 July 2007 (UTC)

While we don't exactly condone copyright infringement, if that's what you're trying to do, what client are you using and what difficulties are you facing? Keep in mind that if you're behind a router you need to port forward the BT incoming port. Splintercellguy 07:18, 19 July 2007 (UTC)

No, you don't need to forward the incoming bittorrent port... It makes for faster downloads, however. --cesarb 09:40, 19 July 2007 (UTC)

Which is basically a need, but true :). Splintercellguy 09:46, 19 July 2007 (UTC)

Delete corrupt file

On an ext3 system (mounted via NFS), I have the following files...

[kainaw V_2006_03_02]$ ls -al
ls: cannot access lab.csv: Input/output error
total 12
drwxrwxr-x 3 kainaw kainaw 4096 2007-07-18 14:47 .
drwxr-xr-x 7 kainaw kainaw 4096 2007-07-19 13:30 ..
?????????? ? ?      ?         ?                ? lab.csv
drwxrwxr-x 2 kainaw kainaw 4096 2007-07-18 14:47 V_2006_03_02

Notice that the directory is the same name as the parent directory. If I cd into it and ls, I get the same results (it is the same directory inside itself). So, how do I remove the broken file (lab.csv) and then delete the directory that has itself inside itself? I've tried rm -Rf V_2006_03_02, but that obviously didnt' work. -- Kainaw^(what?) 13:54, 19 July 2007 (UTC)

What happens when you do each of these commands? --TotoBaggins 16:20, 19 July 2007 (UTC)

rm lab.csv
rmdir V_2006_03_02

I get...

[kainaw V_2006_03_02]$ rm lab.csv
rm: cannot remove 'lab.csv': Input/output error
[kainaw V_2006_03_02]$ cd ..
[kainaw V_2006_03_02]$ rmdir V_2006_03_02
rmdir: V_2006_03_02: Directory not empty
[kainaw V_2006_03_02]$ rm -Rf V_2006_03_02
rm: cannot remove 'lab.csv': Input/output error

I assume I have to delete the inode directly. -- Kainaw^(what?) 17:21, 19 July 2007 (UTC)

You'll probably need to unmount and fsck the original volume on the NFS server. You might want to try remounting the NFS share on the NFS client, in case it is a case of the NFS client getting very confused. -- JSBillings 17:57, 19 July 2007 (UTC)

Agree with the above: unless it's a confused NFS client, it's best to run a fsck on the server. On most distributions I've seen, you can create a magic file (/forcefsck IIRC) which will make fsck run on next boot. Or, if it's not the root fs, you could try unmounting it and running fsck by hand. --cesarb 18:43, 19 July 2007 (UTC)

I guess that's the best. I'll have to back it up first. It is a 30TB JBOD that has the bad file on it. So, it will take a while. -- Kainaw^(what?) 19:00, 19 July 2007 (UTC)

Ouch. Running a fsck on that much data will take a bit of time... --cesarb 19:58, 19 July 2007 (UTC)

(not an answer to your question, which does look like a corrupt inode, but a suggestion for the future) Rather than that mondo JBOD, you may find aggregating at the filesystem layer (rather than the block layer) advantageous. So you'd have a separate filesystem per physical disk, and you'd aggregate them into a single volume with UnionFS and you'd share that over NFS. The advantage is obviously that you only have to fsck one disk, not the whole kaboodle (and indeed all the other guys can be up while you're doing that, with only micro interruptions to add and remove it). This is a nice solution of the volume is essentially read-only (like a movie collection), with only occasional writes (the writer needs to write to the underlying filesystems, and needs to worry about what will fit where). -- Finlay McWalter | Talk 23:17, 19 July 2007 (UTC)

Google

What is the difference between google.co.uk and googler.co.uk? Are they the same company? Hyper Girl 14:25, 19 July 2007 (UTC)

No. Google owns google.co.uk. Jon Richardson owns googler.co.uk. It is not uncommon for people to buy names similar to popular websites in the hopes of profiting off typos. -- Kainaw^(what?) 14:37, 19 July 2007 (UTC)

vista vs xp

a friend of mine installed vista and the graphics of his comp are super.can someone make his xp lets say wallpaper or his dexktop look really cool.as in make the images sharper —Preceding unsigned comment added by 212.49.89.235 (talk • contribs)

Vista isn't making the graphics sharper. Graphics are handled by the video card (regardless of the operating system). What Vista does do is hog up a lot more memory so they can add more shadows around the fonts to make them look cleaner (instead of the pixelized look often seen in XP). You can go into the display properties of XP and add anti-aliasing to your fonts - and watch the computer slow down. As for the wallpaper, just get the image file and use it as your wallpaper in XP. -- Kainaw^(what?) 14:47, 19 July 2007 (UTC)

what is anti-aliasing?howz it done —Preceding unsigned comment added by 212.49.89.235 (talk • contribs)

This is an encyclopedia. You can type anti-aliasing into the search box and hit go to learn about what it is and how it is done. -- Kainaw^(what?) 15:00, 19 July 2007 (UTC)

The method of anti-aliasing used in Vista is called ClearType. It's also available in XP in the display properties. — Matt Eason ^{(Talk • Contribs)} 19:49, 19 July 2007 (UTC)

Problem with hibernation

Can I change the swap space for my Ubuntu 7.04 without reinstallig it again?(I have problem with hibernation.My computer does not hibernate while running Ubuntu and shows error low swap space).If yes,how?Is there any other way I could enable hibernation? —Preceding unsigned comment added by 202.68.145.230 (talk • contribs)

You can use a tool to resize the partitions to increase the swap partition size, but this can be somewhat complex. If you're using LVM, you can resize one of the logical volumes and create a new swap logical volume. It really depends on how you've got your system set up. -- JSBillings 16:10, 19 July 2007 (UTC)

What is the best way to use Python under both Windows and Cygwin?

I want to use Python on a computer with Windows and Cygwin, but I'm not sure what is the best way to do it. I can install both the Windows version of Python and the Cygwin Python package, but I will have two separate installations that may or may not behave identically. I want to use Python IDEs written for Windows for writing and debugging scripts, and have the scripts work under Cygwin in conjunction with utilities written for Unix. Any advice?

I would just install both and use the Windows one to run your IDE and the Unixy one for use with your Unixy scripts, since it would presumably be built to be expecting a Cygwin environment. Disk space is cheap. --TotoBaggins 16:24, 19 July 2007 (UTC)

Java linking FORTRAN

Hi Wikipedia Community:

I would like to migrate a program used for neutrino mass calculations in particle physics. It is written in FORTRAN, and has dozens of subroutines in many different files. I'd like to translate it to Java, which is a much more structured language.

However, I'd like to translate it just one subroutine at a time, so we can test them as we go. My plan is the following:

We place all the FORTRAN subroutines into files, compile them to objects (*.o), and place them all in a library file (*.a). Once our FORTRAN library is ready, we write the main() method of the program in Java, and we call the low-level compiled FORTRAN subroutines in the Java code. Then, we link this Java/FORTRAN hybrid and compile, generating one executable file.

I need guidance in the following: Once the FORTRAN library is ready, how can I manage to call a FORTRAN subroutine in the Java code? I believe it should be possible, since the FORTRAN library is already compiled into low-level linux code...

Thanks a lot, people!--Waldsen 16:12, 19 July 2007 (UTC)

I assumed you'd need JNI, so I googled JNI Fortran and found this. -- Kainaw^(what?) 16:23, 19 July 2007 (UTC)

I wouldn't recommend translating numerical code from Fortran to Java. Take a look at How Java’s Floating-Point Hurts Everyone Everywhere. It will also probably be slower. It would be best to keep your numerical code in Fortran (if your problem is that it isn't structured enough, perhaps you might be using an older version of Fortran), and only call it from Java. --cesarb 18:35, 19 July 2007 (UTC)

How much slower is Java? We usually have a FORTRAN code running for aproximatedly 72 hours (on a PC). How much longer would the same calculation take with Java? You say Java has problems with floating point operations, what about C++? --Waldsen 19:16, 19 July 2007 (UTC)

I have no idea how much slower Java is for numerical code. IIRC, the Fortran compiler is able to do some optimizations that the C++ (and Java) compiler cannot do (in C/C++, function parameters can alias each other, and in Fortran they cannot by default), but C++ libraries can use metaprogramming tricks (see for instance the blitz++ library) to gain extra speed. The best way to know would be to try implementing it and benchmark (and also compare the output to see if it agrees). If the new code is slower, keep the old one. You could also take a look at OpenMP to speed things up. --cesarb 19:56, 19 July 2007 (UTC)

When concerned about speed of Java, two important things: (1) always remember to use the optimizing compiler, i.e. run your program with "java -server". (2) Benchmark your application instead of trusting rumours and guesses. When benchmarking, remember "java -server". 88.112.43.205 20:33, 19 July 2007 (UTC)

21" or 22" LCD Monitor

I'm trying to find a 21" or 22" LCD Monitor with a traditional 4:3 aspect ratio, from a respectable manufacturer, for a reasonable price. I've searched Yahoo!, NexTag, PCConnection, and Staples with no success.

I will be using the monitor primarily for text (program) editing, with aging eyes, so sharpness, contrast, and brightness are more important than refresh rate. I am in the US (near Boston), and the monitor will be hooked to a machine running Windows Vista (not my choice). Matchups 17:11, 19 July 2007 (UTC)

I have two 21" monitors. They are acceptable. I just kept checking WalMart, Target, Office Depot, and Staples online every week or so until WalMart had a sale on some ($299/each about two years ago). That was dirt cheap at the time. So, there's a burnt out pixel on the top right of one display, but it was cheap. As long as you don't have to put it side-by-side with a much better monitor, you'd never know the difference. Being LCD, the contrast/sharpness beats the hell out of my old CRT monitors. -- Kainaw^(what?) 17:32, 19 July 2007 (UTC)

I'd like to emphasize that my search is specifically for a 4:3 aspect ratio. Matchups 19:30, 19 July 2007 (UTC)

Newegg's listing of 20". Higher than 20", the price goes up spectacularly - do one or two inches really matter so much? (if they do, consider buying two smaller monitors for the same price). As I've sure you've noted, widescreen monitors are much better price-wise and are vastly more popular for some reason. -Wooty [Woot?] [Spam! Spam! Wonderful spam!] 19:42, 19 July 2007 (UTC)

No, they don't matter that much, but they matter a bit and I was hoping that the price would be more in line with 21" wide or slightly more than 20" normal (the latter of which I'm about to get) and that maybe there was a good one hiding somewhere and I just couldn't find it. I guess not. Thanks. Matchups 02:04, 20 July 2007 (UTC)

Editing Linux

Okay, i have been developing in VB for a while, and started the C Family a year or so ago. I would like to now have a go with the Ubuntu soure code, and modify it a bit. Whats the best way to edit Ubuntu, as im guessing there is no GUI Program that will do it... Adamlonsdale 17:23, 19 July 2007 (UTC)

What part of Ubuntu? It isn't a "program". It is a collection of programs, wrapped up in a pretty bow and called "Ubuntu". Do you want to edit the kernel, the network drivers, KDE or Gnome, Firefox...? Whichever it is, they are almost all open source. Go to the homepage for the project and join the development team. Download the source from the CSV and have a whack at it. -- Kainaw^(what?) 17:30, 19 July 2007 (UTC)

I was thinking more of the general GUI. Then compiling it onto a CD, sort of like small edits of ubuntu, building up to a bigger one. Ill take a look! Thank Adamlonsdale 17:35, 19 July 2007 (UTC)

The GUI is controlled by X.org with either GNOME or KDE handling window management. -- Kainaw^(what?) 17:46, 19 July 2007 (UTC)

A lot of linux programmers use emacs or vim to edit their code. Eclipse is also a fairly common IDE for people who want the whole integrated environment. You'll also want GCC to (re)compile the software. -- JSBillings 17:53, 19 July 2007 (UTC)

untitled question

I have a 'homepage' in one of the many chat rooms around today, and I would like to install a media player for playback of a few favorite songs. I am being asked to provide a " url "for the songs and I'm afraid that I don't know what that it! Could you provide me with an answer please. Thank youMtnbum51 23:48, 19 July 2007 (UTC)

Next time, please create a new question instead of piggybacking on an existing one. What media player are you using, and where are the songs stored? Splintercellguy 01:40, 20 July 2007 (UTC)

First, you have a website, not a homepage in a chat room. Second, the URL is the address of the file. For Wikipedia, the URL is en.wikipedia.org. It's what you type in your address bar. You'll need to either upload the songs somewhere or, if they're already on the Internet, provide their URLs. -Wooty [Woot?] [Spam! Spam! Wonderful spam!] 02:32, 20 July 2007 (UTC)

Technically, a URL (or URI) has to include a scheme, such as http or ftp or gopher. The URL for Wikipedia would then be

http://en.wikipedia.org/

. -- JSBillings 13:51, 20 July 2007 (UTC)