Wikipedia:Reference desk/Archives/Computing/2007 March 31

Welcome to the Wikipedia Computing Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

March 31

Sharing /home between two linux installations

Someone on the Ubuntu forum said that it is inadvisable to share the /home partition between two different Linux installs because this directory is used for program settings and can cause conflicts if programs on both installs are editing the same files. Is this the case? Will I really need to split my /home partition in two peices to have two installs on the same machine? --Seans Potato Business 01:58, 31 March 2007 (UTC)

Some applications do nasty things, and install libraries in the user directories. If your /home only has documents and no binaries or settings, you should be fine, but everyonce and a while, you might run into a hidden file or other weirdness. I think that Mozilla is an example of one of these applications, but I dont see any specific problems, since the plugins are mostly non-speficic, but I ran into a problem, with a flash install and a ubuntu/fedora mix. Flash installed and ran perfectly under fedora, but would not work under ubuntu. Deleting the application, and installing it under ubuntu, and then getting flash to work under that, then switching back to fedora fixed it, but it was a real head scratcher. It was all a hack to get real audio to work, from a radio station that had their real media front end driven by flash. Worse thing is an application has a user component that might crash upon booting, but you should keep your linux installs handy. ( Hint: I use gentoo/old redhat/ and didnt get the same problem ). Artoftransformation 03:40, 31 March 2007 (UTC)

For just file storage, it won't be a problem, but sharing config files for the same user might be tricky. —The preceding unsigned comment was added by 58.163.152.116 (talk) 05:47, 1 April 2007 (UTC).

You can always have different home directories(per distro) within the same /home partition. You could even have your rc scripts rename dotfiles/whatever as needed. I personally would share the home partition and only put out fires when/if problems happen. Most of the time you will be running similar programs in different distros, so they should usually handle user config files written under a different distro without problem. Obviously YMMV so look in your home directories and find out what's important. -- Diletante 16:34, 1 April 2007 (UTC)

object oeriented programming

what is object oriented programming in C++ ?203.145.188.131 02:01, 31 March 2007 (UTC)

Confusing. :-) StuRat 20:49, 2 April 2007 (UTC)

The articles on Object-oriented programming and C++ explain it. -- Diletante 02:19, 31 March 2007 (UTC)

Torpark

Just to clarify, if I use Torpark, I know outside people can't see what I'm accessing, but can my systems administrator who controls my router? 82.34.242.138 02:17, 31 March 2007 (UTC)

Your admin would be able see the encypted traffic to the tor onion routers address, but he could not be able to tell what specific addresses you were accessing through those routers. So, no. —Mitaphane _?|! 02:45, 31 March 2007 (UTC)

If you need encryption, use SSH. Splintercellguy 23:07, 31 March 2007 (UTC)

Or just use Torpark, which he is doing. Why would you use both? --Oskar 13:42, 1 April 2007 (UTC)

Which is faster? Internal PATA or External Firewire 800?

I'm considering upgrading my Mac's hard drives. I was curious which hard drives are faster (all things being equal): Internal P-ATA or external Firewire 800? FW800 seems like it would have the overhead of the FW800 bridge, while P-ATA is well, parallel. --72.202.150.92 02:54, 31 March 2007 (UTC)

It doesn't really matter as ordinary harddrives cannot saturate either of them. If you need to move it around, get a firewire one, otherwise get a PATA one. --antilived^{T | C | G} 03:52, 31 March 2007 (UTC)

Free Vector Graphics Editors

Does anybody know of any good quality free Vector Graphics editors (ones which have good tutorials would be a bonus). Ideally something of the quality of GIMP or Blender, but for vector graphics. --Kiltman67 04:33, 31 March 2007 (UTC)

Inkscape. Easy to use, produces SVGs (the standard open vector format; Wikipedia and other Wikimedia sites support them natively, as do Firefox and other browsers to an extent), and so forth. -- Consumed Crustacean (talk) 04:42, 31 March 2007 (UTC)

Xara Xtreme is another one, though I haven't used it. I'm an Inkscape fan myself. We also have an article on comparison of vector graphics editors. --24.147.86.187 00:04, 1 April 2007 (UTC)

Trialware

How can you have the trialware forever without registering or ordering it?Dudforreal 08:17, 31 March 2007 (UTC)

Well you can't really. That's how developers make their money. In some cases the developers are kind enough to provide more than just a DEMO verion of their applications, or a limited/restricted version of their programs- instead they give you the full program in trial mode, that just stops working after a few days. Then if you decide you still need it, you buy it.

That said, there are illegal ways of overcoming the trial limitations - by reverse engineering the software, or findin an illegal registration key/serial number, or a 'cracked' copy off the net. But I must strongly advise you, if you can afford to buy the actual software legally, please do so. And even if you can't afford to, then look for a free alterntive. Rfwoolf 11:15, 31 March 2007 (UTC)

Clock on computer

How can you change the time on the computer to anything you want?––Dudforreal 08:29, 31 March 2007 (UTC)

Let's assume you're using Windows... right-click on the clock display and select adjust date/time. --Multivitamin 09:51, 31 March 2007 (UTC)

You can also edit the time in your system BIOS - with some discretion, you have to be careful about everything you do when editing the System BIOS - when your computer is booting up, there will usually be something saying "Press F2 to edit the Sytem BIOS" - on some sytems it may be pressing the DEL key. Then carefully and gingerly edit your time and date settings, before selecting "SAVE AND EXIT" - but be careful about fiddling with other settings, it could cause your computer to stop operating - if you've fiddled with something and you're unsure, simply power your computer off - or hit the reset button - or Ctrl + Alt + Delete - or select "Exit WITHOUT Saving". Rfwoolf 11:11, 31 March 2007 (UTC)

Of course, if your trialware is smart enough to keep track of "runtime hours", even this trick won't allow you to keep illegally running the trial forever.

Atlant 11:37, 2 April 2007 (UTC)

Assuming your'e using Windows though, you've got to make sure that "Sychronize with Time Server" or something akin to that message isn't check-marked. Otherwise, your clock will auto reset itself to the correct time for your time zone.Kevinwong913 01:36, 4 April 2007 (UTC)

Downloading automatically nested files

Hi. I can see the files in the folder of an Apache server. Those files are pdf files, and they are quite a lot, I would get pretty tired if I downloaded all one by one, right clicking and so in each one. Do you know any way to do this automatically? Something like, OK, download everything in this folder and its sub folders. Thanks in advance. --Taraborn 09:19, 31 March 2007 (UTC)

Just trying to help here, have you heard of an FTP application like FileZilla (freeware), where you can select all the files you want and right-click and say "Download" and it wll one by one download them for you. Rfwoolf 11:30, 31 March 2007 (UTC)

You can use a program called HTTrack web site copier. You give it your URL of the directory, and ask it to gather onelevel of files. It will then download the complete list. On Linix or unix systems or possibly windows there is wget also. GB 11:34, 31 March 2007 (UTC)

Or indeed Down Them All, which is free software (GPL'd). If all these files are on seperate pages, you'd need a web crawler. --h2g2bob 02:39, 1 April 2007 (UTC)

I always used wget as I see another mentioned (there are windows versions). You just set it to recurse, not to recurse up the directory (or off website) the retry count, and the recursion level and you're pretty well set. Wget has lots of useful parameters (taking files as input lists, etc). Root⁴(one) 15:31, 1 April 2007 (UTC)

Yeah I usually use wget too, if you need more control, like deleting local files that are not on the server lftp comes in handy. -- Diletante 16:18, 1 April 2007 (UTC)

XP Home and XP Pro

If I had a computer with legal XP home installed and working and tried to install a bootlegg version of XP Pro over it, what would happen? —The preceding unsigned comment was added by 88.110.49.118 (talk) 17:16, 31 March 2007 (UTC).

It would work fine, but probably fail Windows Genuine Advantage. Splintercellguy 18:49, 31 March 2007 (UTC)

So that means I wouldnt get the free updates etc? —The preceding unsigned comment was added by 88.110.49.118 (talk • contribs).

I remember reading that Microsoft allows critical security updates (bug fixes) to install in illegal installations, but you won't be able to upgrade software like Media Player. -- ReyBrujo 19:23, 31 March 2007 (UTC)

OK Many thanks to all respondents for that info. Now the final (killer) question: Is it worth doing???

If you have to ask, probably not. Not trying to be condescending, but Pro really doesn't add much for the average user. "The most common editions of the operating system are Windows XP Home Edition, which is targeted at home users, and Windows XP Professional, which has additional features such as support for Windows Server domains and dual processors, and is targeted at power users and business clients." In other words, if you currently have no reason yourself to want XP Pro, then no, it's not worth it. --Wirbelwindヴィルヴェルヴィント (talk) 19:43, 31 March 2007 (UTC)

My two cents are that it's a lot of hastle to do and basically voids your XP Home, which you've presumably paid for (or which came with the PC). There's no real need to, and most things which Pro can do can also be done through third party software [other than the component stuff]. For instance, remote desktop - so so so many different programs for that. JoshHolloway 19:50, 31 March 2007 (UTC)

Well thank you all so much for that advice. I got the answer I was (sort of) hoping for. Arent the reference desks volunteers helpful and knowledgable!!

How to get a UK ip address in the States

I would like to be able to be able to stream tv shows from UK websites, Channel 4, for example. However, I need to have a UK ip address to be able to do so. Being that I am in the US, this is a problem.

Is there anyway I can obtain a UK ip address, through tunelling, proxies, vpn, or something else? If you can help, it would be much appreciated.

what about finding a proxy located somewhere like london and use that? It might be slow though...Coolotter88 21:24, 31 March 2007 (UTC)

Just search for an open proxy in the UK. --h2g2bob 02:32, 1 April 2007 (UTC)

Similarly you can use tor, specify UK exit nodes in the config and if you don't care about strong anonmity you can set the number of hops down to 1 and it should work like any other proxy. (note: i have never done this) -- Diletante 16:22, 1 April 2007 (UTC)

html/css: wordwrapping so lines are equal length

So, I have have a table cell (or any other rectangular container of text). I write a long stream of text-- one that's too wide to fit on one line. The browser will word-wrap and create two lines: the top one will be as wide as possible, the bottom line will contain the remainder of the text. For most purposes, this is fine, but in some cases, it's ugly having one huge line above one tiny one.

Suppose I instead wanted the text to wrap in such a way that the top and bottom lines were roughtly of equal width. Just inserting line breaks on my own isn't possible, of course, because I don't know how wide the browser will be. Is there anyway to do this? --Wouldbewebmaster 21:31, 31 March 2007 (UTC)

I suppose you could set the property text-align:justify for each TD. However this only works for every line, except the last one. So if your table cells were only two lines of text, it would still be off. —Mitaphane _?|! 23:47, 31 March 2007 (UTC)

Trying To Run Program - should be simple

I compiled my "hello world" program, and tried to run it:

sean@linux-vqrj:~/Desktop> gcc hello.c
sean@linux-vqrj:~/Desktop> a.out
bash: a.out: command not found

Why wont it run? I'm using openSUSE 10.2 --Seans Potato Business 23:08, 31 March 2007 (UTC)

Without specifying an output executable, won't GCC default to hello.out? I think that's the problem. —Mitaphane _?|! 23:36, 31 March 2007 (UTC)

No, it defaults to a.out. However, you haven't set your path, therefore everytime you want to run a program that is in the current directory, you will have to type ./ before it. Thus, to run your program, try ./a.out -- ReyBrujo 23:41, 31 March 2007 (UTC)

Yeah, it'll either be ./a.out, or it will need chmod a+x a.out to set it to execute permissions (which it should be from gcc, so it's probably the first one). --h2g2bob 02:29, 1 April 2007 (UTC)

Correct, it should be ./a.out in bash. You're probably used to CSH or something where you just type a.out. I was confused when I first switched to bash too. --Wirbelwindヴィルヴェルヴィント (talk) 04:10, 1 April 2007 (UTC)

It's not a shell thing. It's a path thing. —The preceding unsigned comment was added by 58.163.152.116 (talk) 05:45, 1 April 2007 (UTC).

./a.out You shouldn't have to set permissions, gcc does that for you right? Well, it does for me.--71.195.124.101 04:14, 1 April 2007 (UTC)

And if it didn't set executable permissions, you wouldn't be able to run it anyway. So that is obviously not the issue. --Spoon! 09:50, 1 April 2007 (UTC)

IIRC the reason that the current directory is generally not placed in the path just because if you change directories to a directory with a trojan ls or dir command, and then attempt to execute ls, you'd possibly be executing that ls instead of ls proper. A smart guy would write his trojanized ls so that ls wouldn't even be visible to itself (at least for most uses of ls). It might even do its thing and delete itself. Therefore, its possible you'd never even know your computer was briefly hijacked! You possibly can get away with adding the current directory to the path if you reorder the path (maybe prepending "." to the path instead of of appending it, I don't recall which), but still, it is just easer, probably more secure, and more conventional to just remember to type ./foo Root⁴(one) 22:44, 2 April 2007 (UTC)