Wikipedia:Reference desk/Computing

Welcome to the computing section
of the Wikipedia reference desk.

skip to bottom

Select a section:

• Computing
• Entertainment
• Humanities
• Language
• Mathematics
• Science
• Miscellaneous
• Archives

Want a faster answer?

Main page: Help searching Wikipedia

   

How can I get my question answered?

• Select the section of the desk that best fits the general topic of your question (see the navigation column to the right).
• Post your question to only one section, providing a short header that gives the topic of your question.
• Type '~~~~' (that is, four tilde characters) at the end – this signs and dates your contribution so we know who wrote what and when.
• Don't post personal contact information – it will be removed. Any answers will be provided here.
• Please be as specific as possible, and include all relevant context – the usefulness of answers may depend on the context.
• Note:
  • We don't answer (and may remove) questions that require medical diagnosis or legal advice.
  • We don't answer requests for opinions, predictions or debate.
  • We don't do your homework for you, though we'll help you past the stuck point.
  • We don't conduct original research or provide a free source of ideas, but we'll help you find information you need.

Ready? Ask a new question!

How do I answer a question?

Main page: Wikipedia:Reference desk/Guidelines

• The best answers address the question directly, and back up facts with wikilinks and links to sources. Do not edit others' comments and do not give any medical or legal advice.

See also:

• Teahouse
• Help desk
• Village pump
• Help manual

April 16

Microsoft Surface Tablets Pro 4 and the Book question

Hi there. I feel I need a tablet computer although I have a vague idea if they can do what I need. I know you can take a pen and write on the screen or paint a picture. That is fine but it is not what I need. I need to draw complicated 3-D images but not usual architectural designs like industrial building. I need to draw 3-D geometric figures like a globe with parallels and meridians. I would prefer if the tablet had those preinstalled with various parameters subject to change with an option of changing the viewing angle, etc. I also want it to have programming capabilities (C/C++ for instance) that would allow me to make graphics of some special functions and store the result in a file. I want this file to be compatible with some Linux applications, e.g gnuplot. I also want it to correct my input, e.g. if I drew an imperfect cube the tablet would make all lines connected and straight.

I googled for user manuals but could not find any. There is a user guide but that is very small, 33 pages. It does not really describe what it can do. Any help in understanding the surface hardware will be appreciated. Or alternatively perhaps there are other advanced systems out there, please advise. Thanks --AboutFace 22 (talk) 17:56, 16 April 2016 (UTC)

Re: "I also want it to correct my input, e.g. if I drew an imperfect cube the tablet would make all lines connected and straight". In 2D this is called grid snapping, but I don't know how it could work in 3D, because there's no way to specify the depth of each point you hand draw. You'd need some other input device to control the depth of the points you draw. StuRat (talk) 18:11, 16 April 2016 (UTC)

Thank you StuRat. This feature not that important actually. I understand the problem. I want to find a comprehensive user manual and none is available.--AboutFace 22 (talk) 00:18, 17 April 2016 (UTC)

Is it a requirement that it run on a tablet? It sounds like you're describing something like Sketchup. CodeTalker (talk) 00:53, 17 April 2016 (UTC)

Are you confusing a Tablet computer with a Graphics tablet (and appropriate software running on any computer)? Dbfirs 08:12, 17 April 2016 (UTC)

Thank you for pointers. I may be somewhat confused, that's true. .--AboutFace 22 (talk) 00:18, 18 April 2016 (UTC)

April 17

SearchFaster - another piece of malware

Hello. While working with GnuPlot I did some search and inadvertently downloaded so called SearhFaster. Only an hour later I realized what the sucker it is. It misplaced the Google search completely and in the address window I can see this link:

h ttp://search2.searchinfast.com/?uid=9bfa1dd9-636c-49e7-b5e2-8195721628a1&uc=20160416&ap=appfocus5&source=search-bb8&page=homepage&implementation_id=dm_0.2.1

The search itself gives me totally different results. Instead of some academic stuff I get commercials: buy this, buy that. The download was misleading and I don't know how to get rid of it. My OS is Ubuntu 14.04. The search through directories gives me nothing. How to get rid of this nuisance?

Thanks, --AboutFace 22 (talk) 00:25, 17 April 2016 (UTC)

I've added a space to the link to disable it. Rojomoke (talk) 06:09, 17 April 2016 (UTC)

Probably this is a browser add on, so look there. For example, if you are running Chrome try typing chrome://extensions and chrome://plugins in the address bar. --TrogWoolley (talk) 08:13, 17 April 2016 (UTC)

Thanks, my OS is Ubuntu 14.04. I managed to remove it from a list of search engines, also removed all other search engines but Google. There is a check against Google name. The default search engine is Google now, the malware still shows up in address window when I need to do the search. How can I get to add-ons for the Browser? It is Mozilla FireFox. --AboutFace 22 (talk) 17:08, 17 April 2016 (UTC)

A question somewhere between Computing to Cognitive sciences to Philosophy

Is there a difference between a "Semantic field" to a "Namespace" or the two terms generally have a similar if not identical meaning? Ben-Yeudith (talk) 05:33, 17 April 2016 (UTC)

A namespace is organized around a common name. For example, the surname of a family identifies the members of it. Or, the .gov ending identifies governmental pages. Files in a directory are all named <directory>/file

A semantic field is organized around a common meaning, even if the names are completely unrelated. For example, "chair" and "sofa" might belong to the same field "object you can seat on." --Scicurious (talk) 18:28, 17 April 2016 (UTC)

Namespace and semantic field are both blue links. I'd say that "namespace" tends to be used more in the context of artifical languages, and cam be described through formal statements and sets, etc. Semantic fields are more nebulous, and cannot be so succinctly defined. See also Controlled vocabulary and Controlled_natural_language, which are additional related concept that fit in to this milieu. SemanticMantis (talk) 14:35, 18 April 2016 (UTC)

Folder Icons & Folder Pictures

1. What's the difference between the two?  Done
2. How do I change them as a whole, also restore it back to the Original?
3. Where can I find luxurious/futuristic icons...?

Apostle (talk) 09:29, 17 April 2016 (UTC)

1) These days, an icon is just a smaller pic. (At one time, icons also used fewer colors, to avoid using up the limited color palettes available on earlier PCs, but that issue has gone away now.) However, note that just scaling down a large pic to create an icon doesn't give very good results. Instead, you want a simplified "cartoonish" version of the item, to be visually clean. StuRat (talk) 14:50, 17 April 2016 (UTC)

I have a feeling that this question is about a file browsing program that has optional pictures to replace the standard folder icon. This is common when browsing media folders. For example, in a music folder, the cover art for an album will commonly replace the standard folder icon. If that is actually what is being asked, we need to know what program you are using - at least the operating system. Otherwise, you will get a dozen answers, each specific to a program that you are not using and, therefore, will be of no use to you. 209.149.115.199 (talk) 11:50, 18 April 2016 (UTC)

I'm using Windows 7 Ultimate. I'm planning to change Folder icons all in one go, and of course, restore it to default when I'm bored... I'm not using a special software, unless you guide me with an 'open source' software. I'm aware of the picture and media glancing/viewing icon and was concerned about this mainly, cause I wondered if changing the first icon would clash with the second (media, picture icon). I couldn't find the destination of both the icons, what I found, I couldn't grasp which one was the second icon... -- Apostle (talk) 18:40, 18 April 2016 (UTC)

Scanning and archiving: standard settings

What is the most recommended settings for scanning a pile of documents and archiving them for the future?

They are basically letters, notes, and forms. No color or color not important (that is, written with a blue pen), and no pictures.

I'll use 300 dpi, but I wonder, what file format should I choose? Is there a file format that will stand the passage of time? That is, 5-10 years from now, could it be that no common tool will be able to open a file scanned today? --Scicurious (talk) 18:20, 17 April 2016 (UTC)

Sorry, but predicting the future is beyond the scope of the Reference Desk. We do not know what tools will be common in 5-10 years—let alone, more importantly, 50-100 years. --69.159.61.172 (talk) 18:33, 17 April 2016 (UTC)

I am pretty sure someone knowledgeable in archiving will have a better answer than yours. And there is no reason to suppose that 50-100 years in the future is more important than 5-10 years.--Scicurious (talk) 19:19, 17 April 2016 (UTC)

GIF was created 29 years ago and is still in use today. There's no reason to assume that it will disappear in 5 years time. You can pick any widespread format in use today (jpg, png, gif, pdf, tiff) and be reasonably confident that it will still be readable in 5, 10, or even 50 years from now. Of course, if you're trying to protect the data from a doomsday scenario where the internet has been destroyed and you'll only be able to use whatever computer parts and software you manage to salvage in the post-apocalyptic wasteland, then all bets are off. For documents where color is not important, reduce the image to black and white to save space. A 300 dpi scan of a page of text might be 1MB as a jpg, but only 100Kb as a black and white gif. The threshold operator in imagemagick works nicely for this. 61.33.191.135 (talk) 19:52, 17 April 2016 (UTC)

Word was also created 20+ years ago, but ... . Anyway, are GIF tools of today back-compatible with the GIF 29 years old?

And, some version of .pdf is not an option? Scicurious (talk) 21:03, 17 April 2016 (UTC)

(EC) PDF/A is a format designed for the purpose of long term archival. While the actual advantages in the case of scanned documents with no OCR is minimal, it may still be the best choice. In terms of compression, it will depend what precisely you want to keep. If you're just storing in black and white i.e. 1 bit as mentioned above there are better compression formats designed for this supported by PDF/A (notably JBIG2 although you'd want to avoid the lossy variant). I do wonder if 300 DPI may be a bit low if you're doing 1 bit particularly if you have very small text or some important imagery on the documents. As has been said above, while it's impossible to predict the future, 5-10 years from now don't seem like a good test for any common image format, or heck less common ones, you'd want to worry more about 50-100 years. The other commonly used alternative is TIFF although I'm not sure what forms of compression are normally used. From what I understand, PDF/A is largely replacing TIFF for scanned documents although obviously some may still prefer TIFF or other formats. Note that TIFF and PDF also support multipage files, although it's more of a standard part of PDF.

TIFF is still often used for archival of digital images from cameras (whether scanned or digital cameras), x-ray machines etc. Possibly uncompressed or with lossless compression. JPEG would be the most likely alternative whether in TIFF or by itself. Although despite it's unpopularity elsewhere, a number choose JPEG2000 for long term archival instead. (And whatever the wisdom of this choice, considering some of the big names involved, it's hard to imagine they aren't going to ensure they have a way to access their content in the future. Although it may be this software would not be something easily usable by random people bearing in mind we have no good idea what hardware and software is going to be like 50-100 years from now. Realisticly this probably applies to other common formats including GIF although the less commonly the format was used for professional archival, the greater risk that even if someone has a way, it may not be easily usable by you.)

See e.g. [1] [2] [3] [4] [5][6] [7] [8] [9] for more discussion. Note as highlighted by some of these discussions, if this is something you really care about you should look in to how you're scanning and processing your documents. Also be aware that some software may claim to produce PDF/A, but don't actually. (It's possible this is less of a problem for scanned documents, but I'm not so sure.)

Nil Einne (talk) 21:44, 17 April 2016 (UTC)

Apple iPhone autocorrect

For the first time in my life, I have a non-Nokia mobile phone, namely an iPhone 5S. It seems to have autocorrect in its text input. It displays popup suggestions sometimes when I am typing a word.

I am having trouble with these popup suggestions. I thought tapping on the popup would accept the suggestion. No, no such luck. Tapping on a suggestion makes it go away and I have to type the full word.

Furthermore, the suggestions are sometimes wrong, and when I finish typing the word, the iPhone decides it knows better than me, and accepts its own suggestion without my authorisation, causing me to delete the whole word and retype it.

So in conclusion, this autocorrect thingy looks like a good idea, but in practice seems to be more trouble than what it's worth. So, how do I actually use autocorrect? How do I accept its suggestions when they're right and ignore them when they're wrong? So far, it's been more of a hindrance than a help. JIP | Talk 20:56, 17 April 2016 (UTC)

That's Apple for you, they know better than you how something is supposed to work. Tapping the auto-correct, as you have noted, dismisses it, you can eventually learn to live with it, or you can just turn it off. I find it the perfect balance of useful enough that I don't want to turn it off (have tried a few times) and annoying enough that it frustrates me on a regular basis.. Vespine (talk) 22:38, 17 April 2016 (UTC)

Oh, something that makes it just slightly more bearable, to "accept" the suggestion, you don't tap it, you can just press "space". As SOON as the correct word appears in the suggestion, you can stop typing the word and press space, this can save you some typing when you get used to it. Vespine (talk) 22:40, 17 April 2016 (UTC)

See my sprawling text below, this is mostly true, but not entirely. It only completes on space under some circumstances, not all. (I just tested it to be sure). SemanticMantis (talk) 14:29, 18 April 2016 (UTC)

Look around for things like "iphone autocorrect hints", e.g. [10] [11]. I did that too when I got an iphone, but it was hard to find a good description, plus the details change a bit over time. So I'll type out some hints that I wish someone would have told me.

It is a bit frustrating to get used to. Assuming you have the latest iOS: When you start to type, you'll see a range of possible completions at the bottom, including the actual text you have typed (inside quotes for some reason). If you want to pick one, just tap it, and the word will get filled in, along with a space so that you can start the next word. If you don't want the suggestion, just hit space or keep typing. So far so good. However, when it's sort of more sure that you don't really mean what you've typed, then one suggestion will turn blue, and that means that when you hit space, your text will automatically get changed, even if you didn't want it to. To keep weird strings that it wants to change, like 'tleprt', you have to (at first) click on the little bit that says 'tleprt' and to override the blue automatically inserted 'teleport' option. Here's a few fun tests that show how awesome/insane/frustrating/magical the system is. Type 'tle'. You probably will see a blue "the" pop up. If you hit space, you get the "the". But if you continue 'tlepr..', eventually you might see "teleport" fill in. Now, if you delete back to tle, you will likely not see "the" as an automatic autocomplete option, because it has guessed that you do really mean something about e.g. tle, and it's trying to be adapt. So from this we learn an important aspect: this magic is context dependent. It depends not only on the current state, but also the history, so it is also path dependent! As you use the phone a bit, it will start to learn what weird words you use, and eventually stop trying to correct them. True story: my phone now sometimes suggests Necrodancer after I texted a bunch of my friends telling them how great that game was. The first few times were frustrating, but it learned quick. Another fun trick, that works best after you've had the phone for a bit. Open up a new email, then just hit the first completion suggestion, then repeat. It doesn't need any seed to start, and you'll get some interesting strings of words based on your past usage. Hope that helps :) SemanticMantis (talk) 17:07, 18 April 2016 (UTC)

April 18

Finding a website's owner

I'm sure that we have an article about the concept of a website that lists who owns what domain names, but I don't know what to call it. I figured it was "DNSR" or something of the sort, because when I try to go to a nonexistent website, my TWC Internet service sends me to http://www.dnsrsearch.com, but neither DNSR nor DNSR server exists. The site's preferences page mentions that I can opt out of the "domain landing service", but domain landing service also doesn't exist. Nyttend (talk) 01:31, 18 April 2016 (UTC)

WHOIS? --Tagishsimon (talk) 01:39, 18 April 2016 (UTC)

So it is. http://www.domaininformation.de/whois provided the information I need (in this case, the fact that http://www.gogle.com, an easy-for-me-to-make typo, is owned by the folks that operate http://www.google.com. I had no idea that WHOIS handled this kind of thing; I thought it was just for looking up the entity to whom an IP address was registered. Nyttend (talk) 01:43, 18 April 2016 (UTC)

WHOIS is used to look up the organization for whom a block of IP addresses is registered as well as look up the registrant information for a domain name. It is becoming more and more popular for domain name registrations to be private, so you can't use WHOIS to get domain name owners from that. Further, the owner of a domain name is not necessarily the owner of a website. I own many domain names that go to websites that I do not own in any way. I am paid to let the website owners use my domain names. 209.149.115.199 (talk) 11:48, 18 April 2016 (UTC)

C++ term for a trivially memcpy-able object

There's a C++ term-of-art, which is on the tip of my tongue but I can't remember. It's used to describe a class whose instances the compiler can safely copy without a copy constructor - i.e. the compiler simply emits an inline memcpy. So it's for classes with only members of elementary types without constructors (or aggregates thereof). It's an acryonym - something like SPOSH or SPOD or the like. I don't see it in Copy constructor (C++) or Object copying. Can anyone remember what the C++ folks call these things? Thanks. 87.114.241.105 (talk) 20:38, 18 April 2016 (UTC)

The abbreviation you're thinking of is probably POD, plain old data, although the technical term is "trivially copyable". See, for example, this site. Tevildo (talk) 20:47, 18 April 2016 (UTC)

Yes, indeed - PODS was clearly what I was almost remembering. Should there be a link to that in the Copy constructor (C++) article? Thanks for your help. 87.114.241.105 (talk) 22:06, 18 April 2016 (UTC)

April 19

How did the 1968 NLS system accomplish video display?

The NLS (computer system) that was used in the 1968 The Mother of All Demos connected via leased telephone lines, to ARC's SDS 940 computer 48 km away. It seems hard to find any documentation on the NLS device itself. Leased telephone lines are a real poor signal path for video signals or anything that has hard latency demands with a simultaneous need for high bitrates. So it must been generated locally. Anyone knows how this was accomplished? keep in mind that in 1968 these things were really hard to accomplish. Bytesock (talk) 02:39, 19 April 2016 (UTC)

The Wikipedia article cites this Wired article, which says "we beamed two channels of video along two microwave links up to San Francisco, bouncing them off dishes above the airport [...] we rigged up a homemade modem – 2,400 baud – to get signals from my console in San Francisco back to SRI over a leased line." So I think the phone line was only for unidirectional keyboard and mouse data. I edited the Wikipedia article to more accurately match what the Wired article says. -- BenRG (talk) 03:09, 19 April 2016 (UTC)

The article uses another link. But thanks anyway for solving the missing piece. This means the "terminal" was in essence like a keyboard-mouse-video console you connect nowadays to KVMs to setup servers etc. Essentially no computing resources at all unless the keyboard and mouse MCU counts (did they even have an MCU?). Computing were expensive then, but it still boggles my mind that it took so long before the commercial aspect got up to speed. The 1970s were about being able to drive a monitor at all. And interfacing 1 kB memories at kHz speeds with paper loading or magnetic tape storage. Btw, how the SDS 940 really accomplished the graphics output is also kind of "in the dark". It seems to resemble the Amiga copper chip somewhat from the description. And is the modem 2400 baud or bit/s? Bytesock (talk) 04:02, 19 April 2016 (UTC)

I think back then baud was synonymous with bit/s, see e.g. Baud#Relationship_to_gross_bit_rate. SemanticMantis (talk) 14:59, 19 April 2016 (UTC)

Yeah, it's almost impossible to deduce what the real speed would have been. But now I have also found one source that claim 1200 "baud" and another that claims 2400. Bytesock (talk) 15:49, 19 April 2016 (UTC)

this is also how modal editors like vi (as opposed to things like EDIT.COM and with a point and click interface) came to be. Drawing windows, menus etc, even in pseudo-graphics, much less pixel graphics, is only practical if you have direct access to the graphic card's frame buffer, but not if your display unit is connected via a slow serial line and you need elaborated control codes to do anything beside line breaks. BTW, this need not be limited to text and can be generalized to vector grpahics. This is the idea behind Unix'/Linux' X Window and Windows' GDI, which use their internal vector languages and furthermore NeWS, a windowing system which employed PostScript, today normally used in laser printers (!). And yes, terminals do have computing resources (the VT100 was built around the 8080, for example) but don't expose them, except accidentally (Datapoint 2200). The terminals thing is also why there is no distinction in Linux between graphical and "console" programs but there is one in Windows and this is decided at compile-time (a flag in the executable file tells Windows whether to open a console window for the program). It's also why Linux has a "terminal emulator" rather than a "console" to start with. What does it emulate? Why, the VT100 (or something very much like it.) Asmrulz (talk) 23:52, 19 April 2016 (UTC)

I don't think the demo had what we'd really call a bitmapped display. As Framebuffer#History notes, even research machines weren't really generating images from RAM until a year or two later. As I understand it, the demo is effectively text mode, with a mouse cursor. A character mode display of that era would be a mostly hardware based character generator system, which takes character codes (maybe ascii) from a RAM page, uses what's effectively a hardware lookup into a character ROM, and strobes that out to the analog raster. The mouse cursor is effectively a hardware sprite, where again the image is generated by hardware working off the raster sync signals, with the software just setting up the image and a few control registers - this achievable in affordable consumer grade technology by 1977's Television Interface Adaptor, so it's reasonable (but, don't get me wrong, still very impressive) for Englebart's team to a built a simple custom one in 68. -- Finlay McWalter··–·Talk 00:01, 20 April 2016 (UTC)

Point-to-point transmission of analog TV signals is effectively outside broadcasting, which the BBC was able to do over a radio connection by 1938. Their history of the efforts to live OB the 1953 coronation talks about them using a custom balanced and co-ax lines but also "ordinary telephone cables with video repeaters" - although obviously the BBC had lots of pull with the GPO (the telephone company), so surely those lines were manually patched at the exchange, and not run through a switchboard or electromechanical switch. It's easy to see how SRI, without comparable influence over Bell System, would opt for their RF solution instead. Their compositing of the camera video signal with their computer video signal would again be done electronically (i.e. in analog hardware). -- Finlay McWalter··–·Talk 00:19, 20 April 2016 (UTC)

Criminal modus operandi database ?

There are fingerprint and DNA databases, but how about one where you can search for a criminal with a similar MO, but in a different jurisdiction, perhaps even another nation. Does such a DB exist ?

I can see that there might be difficulty in categorizing and searching items, like if one profile said "victims were bound", another said "bindings are used", and another referred to "ligatures" (not to mention foreign language versions). So, it's not a trivial task. StuRat (talk) 18:57, 19 April 2016 (UTC)

"The database houses modus operandi, signature aspects, crime scene descriptions/photos, victim and suspect details, and other pertinent information." [12]. By "you" I assume you mean "a person" and not you, StuRat. You, StuRat, cannot search that FBI database unless you have access via a law enforcement agency. SemanticMantis (talk) 20:24, 19 April 2016 (UTC)

Sounds like a step in the right direction, but:

1) It makes no mention of being accessible for additions or searches in other nations.

2) It made no mention of it being accessible by attorneys. This would seem to be important if you are a defense attorney and can find a dozen other criminals in the area with the same MO as the one for which your client is charged.

3) It made no mention of being accessible by crime victims or the private investigators they hire to help to solve crimes the police can not.

4) It listed "150,000 open and closed violent crime investigations". That's only a tiny portion of the violent crimes in the US, isn't it ?

5) Nonviolent crimes might also be useful, say if an arsonist who started by setting dumpster fires has moved on to occupied structures.

6) Also, I'd like to know how the searches get past the problem of different terminology I mentioned in my first post. StuRat (talk) 20:36, 19 April 2016 (UTC)

In a UK context, I would assume that the Crimint system has some of this functionality, but I'm not about to draw attention to myself by making further enquiries! See also the UK-specific articles Police intelligence and Police National Computer. {The poster formerly known as 87.81.230.195} 185.74.232.130 (talk) 13:51, 20 April 2016 (UTC)

Virtual reality

I was watching BBC today, they were displaying something about Shakespeare play. The interesting part was it was getting done in 4D; a camera records the reality ‘’live’’ and then displays it in T.V. Of course, you have to detail the artwork of the virtual reality from beforehand, for example, create the virtual character fully in order to pupate the real person, and so on. Does anybody know what the software is called? -- Apostle (talk) 19:10, 19 April 2016 (UTC)

Is this [13] what you saw, about a game called Play the Knave? If so, it was developed at the UC Davis Modlab [14], and the official website for this VR Shakespeare is here [15]. It seems to me that much of the software would have been custom made, but also there is probably a lot of work done by open source libraries. Here [16] is a list of some of the research publications associated with the project, and that might tell you more. Finally, if you use the "contact us" button on the site, you might get a better description of the tools involved. SemanticMantis (talk) 20:23, 19 April 2016 (UTC)

Yes, its the right one. Thanks -- Apostle (talk) 18:27, 20 April 2016 (UTC)

April 20

Windows 10 updates

I have a Windows 10 computer that is wanting to install updates. It wants to restart, but I have something running that takes weeks to finish, so I don't want to restart until I'm ready. The latest I was able to schedule a restart is a week away. I used to be able to tell it to download updates but not install them until I'm ready. Is there a way to do that in Windows 10? Bubba73 ^{You talkin' to me?} 04:47, 20 April 2016 (UTC)

https://support.microsoft.com/en-us/kb/3073930

https://websetnet.com/defer-block-uninstall-windows-10-updates/

http://www.zdnet.com/article/microsoft-releases-tool-to-hide-or-block-unwanted-windows-10-updates/

http://www.pcworld.com/article/2951807/software-utilities/optional-windows-10-utility-blocks-bad-updates-from-messing-with-your-pc.html

--Guy Macon (talk) 06:35, 20 April 2016 (UTC)

You can't trust Microsoft. So you need to remove the not yet installed files so that they can't be installed and thus delay the whole affair. There has been a release of a tool that terminates the Win10 update "request", use that. In the meantime block these addresses permanently. Someone else has to tell you the details. Another simple solution that MAY work is to yank the network cable. Bytesock (talk) 07:21, 20 April 2016 (UTC)

Thanks, I'd thought about disconnecting it from the network, but I use dropbox to send files back and forth. But that might be the simpliest solution. Bubba73 ^{You talkin' to me?} 20:51, 20 April 2016 (UTC)

In that case you can block everything BUT the dropbox service in you firewall (because you one?). Anyway, the long term solution is to have a program that permanently disables the Win10 upgrade, they exist I just can't recall the url. As usual backup your own files and in this case also the system files, such that you can reinstall. Also consider the option to put the whole windows installation into a VM-sandbox and have regular image backups. Bytesock (talk) 08:43, 21 April 2016 (UTC)

You can also just go into your router and block these websites how ever long you want.

http://windowsupdate.microsoft.com

http://*.windowsupdate.microsoft.com

https://*.windowsupdate.microsoft.com

http://*.update.microsoft.com

https://*.update.microsoft.com

http://*.windowsupdate.com

http://download.windowsupdate.com

http://download.microsoft.com

http://*.download.windowsupdate.com

http://test.stats.update.microsoft.com

http://ntservicepack.microsoft.com

https://technet.microsoft.com/en-us/library/bb693717.aspx Just have to read between the lines a little on this website. They are talking about how to setup a WSUS server for a large corporation. Sierravistaitsolutions (talk) 15:30, 20 April 2016 (UTC)

using the refs code doesn't stay within the section on the reference desk, it still goes to the "bottom" of the whole page, so it's advisable not to use it. There's a special code you can use instead but I can't remember it. Vespine (talk) 06:07, 21 April 2016 (UTC)

@Vespine: It is {{Reflist-talk}} or simply {{Reflist}}. They both catch and display all refs not displayed yet, so they work anywhere you want – see examples in my sandbox. --CiaPan (talk) 10:26, 21 April 2016 (UTC)

RegEx syntax for PHP's preg functions

Because StackOverflow cannot answer this, I thought I'd ask here... Please note that the context of this question is in PHP's implementation of the preg functions.

Suppose I have a string: $s="XXXABCBCBCDXXX"; I want a regular expression that will match all of the BC substrings and return them in the matches array. I tried: /A(BC)+D/, assuming that (...)+ means "match the previous sequence multiple times". I expected to get match $matches[0]="ABCBCBCD", $matches[1]="BC", $matches[2]="BC", $matches[3]="BC". Using preg_match('/A(BC)+D/', $s, $matches);, I get $matches[0] as expected, but then I only get $matches[1]="BC". I don't get the other two matches. This is odd because $matches[0] contains all three BC values. I tried preg_match_all and got $matches[0][0]="ABCBCBCD" and $matches[1][0]="BC". Not any better. How can I get it to match BC multiple times, creating an index in the matches array for each match? 209.149.115.199 (talk) 18:08, 20 April 2016 (UTC)

April 21

Unary Operator in C

What is the output of following code?

#include <stdio.h>
void main(){
 int a=5,v;
 v=(++a)*(++a)+(++a);
 printf("%d , %d",v,a);
}

When I compiled it , I get different result according to compiler.

 In Turbo C ,I get 72,8
 In Dev c++ and Code::Blocks (Based on GNU GCC), I get 57,8
 In C4Droid I get 50,8 

Which is correct and how? Can you explain this for me? Thanks — Preceding unsigned comment added by Amrit Ghimire Ranjit (talk • contribs) 04:52, 21 April 2016 (UTC)

They are all equally correct. You shouldn't increment "a" several times within a statement. If an object is modified more than once in a statement (technically between two sequence points), behavior is undefined. Undefined means any result is allowed, including giving a random number result, crashing the program, or setting your computer on fire. 91.155.193.199 (talk) 06:43, 21 April 2016 (UTC)

To explain what's happend, the evaluation sequences are:

           v=(++a)*(++a)+(++a);
Turbo C        1  4  2  5  3      : (8 * 8) + 8 = 72
GNU C          1  3  2  5  4      : (7 * 7) + 8 = 57
C4Droid        1  2  3  5  4      : (6 * 7) + 8 = 50

The C4Droid sequence might seem the obvious way of doing it, but the other two aren't wrong, just examples of what "undefined behaviour" can mean. Tevildo (talk) 07:21, 21 April 2016 (UTC)

(ec) The expression given has undefined behavior as defined in the C standard. The C standard defines a concept called sequence points, which for the purposes of this discussion can be thought of as the start and end of the statement in question. Performing more than one update to a or accessing a elsewhere in the same expression where it is updated are both cause for considering the operation to have undefined behavior. With undefined behavior, all bets are off. There is not even a guarantee that the results make any sense at all. A google of sequence point yields much further discussion. -- Tom N talk/contrib 06:45, 21 April 2016 (UTC)

Just one clarification. A sequence point is a point in time, not a place in the program. The relevant sequence points are before and after the statement is executed. --69.159.61.172 (talk) 12:04, 21 April 2016 (UTC)

Google Cloud Messaging in China

Does Google Cloud Messaging work for endpoint devices in China? Many Google services are blocked in China, but some are not. I'd like to know whether Google Cloud Messaging is among the blocked services or not. Johnson&Johnson&Son (talk) 06:08, 21 April 2016 (UTC)