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November 28

Dropbox help, only showing file is uploading...

What does that mean and how do I solve it? I want to download this file: https://www.dropbox.com/s/eepj17aloevnvx8/Rigged%20YoloYoshi.object?dl=0 But it won't get past File is uploading... screen. -DaSuperYoshi — Preceding unsigned comment added by 78.70.50.122 (talk) 22:13, 28 November 2015 (UTC)[reply]

November 30

Removing a VPN setup on Windows 7 Pro

I'm trying to "sanitize" a Windows 7 Professional notebook, prior to donation to a charity. It has a corporate VPN setup on it, but I can't find a way to delete it. I cannot do a complete format and reinstall that would have resulted in a "clean" setup on this pc due to licencing issues, so I need a way to delete the VPN setup specifically. Roger (Dodger67) (talk) 13:15, 30 November 2015 (UTC)[reply]

Some googling gave me a few promising-looking links, including this and this - the key point seems to be that you need to delete the appropriate Network Adapter, and you probably have to be logged in with Admin rights. AndrewWTaylor (talk) 14:38, 30 November 2015 (UTC)[reply]

Are you sure you can't do a factory reset? I think on most PCs you don't even need the Windows license key for that. If you really can't, you might want to ask the charity what they expect from donated computers. It's possible they might just wipe them all themselves and do fresh Windows installs, due to concerns about private data left on donated systems. --71.119.131.184 (talk) 21:29, 30 November 2015 (UTC)[reply]

December 1

Setting write protection for only part of an SD card

Anyone know if the write-protection circuitry of SD cards allows for protecting only part of the memory? I'm not talking about the notch. — Melab±1 ☎ 01:25, 1 December 2015 (UTC)[reply]

It depends on what exactly you mean. As I just learned from the article, every SD card actually has a portion of its memory "hidden" to the outside world, available for DRM content. But, if you mean a user-controllable functionality that allows you to mark parts of the card read-only, hypothetically it would be possible, but I don't believe such a thing is supported in the SD standard. The whole-card write-protection is actually not implemented in the card itself. A write-protected card simply tells host devices that it's write-protected, and it's up to the host device to obey this or not. To implement some kind of user-controlled "selective write-protect" you'd have to modify an SD card yourself by flashing the controller with custom firmware, or cracking it open and physically replacing the controller chip. And actually implementing such a feature in the firmware would be difficult. Flash memory controllers do all kinds of complex gymnastics under the hood for wear leveling and other purposes. The physical location of data in the memory can change every time there's a write. SD cards and similar devices like USB flash drives are designed as black boxes; it's not intended for users of the card to know or care about the internal memory layout. --71.119.131.184 (talk) 02:16, 1 December 2015 (UTC)[reply]

The SD card's controller does support write-protection. — Melab±1 ☎ 21:50, 1 December 2015 (UTC)[reply]

Where is the Linux clipboard?

Clipboard_(computing)#X_Window_System is not very clear here. It might even be that this article needs some improvement. In what file exactly is the clipboard content stored? If the xclip tool is installed, would xclip save information to a different location? --Scicurious (talk) 13:20, 1 December 2015 (UTC)[reply]

The clipboard content is not stored in a file. It is held dynamically in memory by the X server. Looie496 (talk) 13:49, 1 December 2015 (UTC)[reply]

And how do programs refer to this information, when we copy-and-paste among them? Or all those clipboard tools, how to they access it? Be it in memory or not, Isn't there a file to be accessed? After all, in Linux, everything is supposed to be a file.--Scicurious (talk) 18:01, 1 December 2015 (UTC)[reply]

Your clipboard might be managed by your X server, or by some other system (like your Desktop Manager). For example, if you use Gnome, your clipboard is the GtkClipboard, a data structure that is designed to hold "data shared between different processes or between different widgets in the same process." Your clipboard will be incarnated differently if you use a different desktop manager or User Interface software.

The block of data that is your clipboard is shared memory, implemented by the user interface software and backed by a lower-level Linux data type; and neither of those things usually exist as a file. Some variants of *nix will allow you to open a file handle to such a shared memory abstraction, but that's an unusual way to access the resource.

"Everything" is not a file: when people say everything is a file, they usually mean everything from a specific set of things - things like directories, sockets, and pipes, as documented in this general overview of the Linux file system. Many other computer resources exist that are not files: memory is not a file; the power manager is not a file; certain types of special-purpose I/O are not files. If you wish to present these resources as ordinary files, you can (sometimes) wrap them inside a file handle (provided that you have privileges to access these resources); but there are plenty of cases where that does not make sense. For example, do you want Linux ACPI interfaces to be accessed in a file-like way? What does it mean to fopen the processor P-states? You could abstract that kind of operation, but a different paradigm already exists to read, modify, and protect those resources.

If you really want to pursue the "everything - no really, everything - is a file" paradigm and chase down that rabbit hole - Linux isn't the right choice for you. You might want to read about Plan 9 file servers - part of the Plan 9 from Bell Labs system. Plan 9 is installable; it is mostly functional; but it is not Linux. You might find that the "abstract entity" called a "file" in Plan 9 is not at all like what you think of when you use a more conventional operating system's file API.

Nimur (talk) 19:13, 1 December 2015 (UTC)[reply]

The short answer is that Linux doesn't have a clipboard. Linux is a kernel. This is sometimes given as a glib answer when it's not really relevant, but here it is. Whatever clipboard you have available is determined by whatever software you're using copy-and-paste in. The X Window System makes three different "clipboards" available to software. Each program is free to pick which one, or none, to use. Some programs like emacs and vim have their own "kill"/"yank" buffers that don't interface with GUI clipboards at all (because they're primarily designed to run in terminals). And you might not even be using X; there are alternatives like running programs directly in a framebuffer, and Wayland is intended as a replacement for X. Android uses the Linux kernel but doesn't use X or Wayland, so I don't even know what it does. This mess is a longtime pain point in FLOSS GUIs; Freedesktop.org has tried to get developers to commit to seamless clipboard use between programs, but as anyone familiar with the FLOSS world knows, it's like herding cats. --71.119.131.184 (talk) 20:21, 1 December 2015 (UTC)[reply]

Still, now that Scicurious mentions it, it is interesting that content which other systems would describe as "on the clipboard" isn't available through a filename under /dev or /proc. At least, as far as I know it isn't. --76.69.45.64 (talk) 21:38, 2 December 2015 (UTC)[reply]

That feature isn't in Linux. It is available in other systems: for example, Plan 9, publishes program memory as a file in procfs. You can use procfs /proc/n/mem to get to the memory image of your clipboard server (whether it is owned by your desktop UI program, by your X server, or by a dedicated daemon).

If you added this feature to Linux, replacing of all the parts of Linux that get in the way, eventually you'd have some other operating system. Some incarnations of such an operating system do already exist.

Nimur (talk) 23:31, 2 December 2015 (UTC)[reply]

Did you read the procfs article, which tells you it's existed since V8 Unix, and is part of the Linux kernel? But anyway, procfs doesn't include any specific clipboard function. It just gives you access to a process's memory. You can get any data you want out of it, if you're prepared to dissect the memory dump. The point I was trying to get across above is that the Linux kernel contains no clipboard. A "clipboard" is part of the desktop metaphor and is implemented in GUIs people run on top of Linux. You could propose that the kernel add a clipboard functionality that it makes available to processes, but it would probably be rejected as something that belongs in userspace. --71.119.131.184 (talk) 00:49, 3 December 2015 (UTC)[reply]

December 2

Neural Nets, FOL, and Set Theory

I've been doing some readings in evolutionary psychology (EP) lately and one thing keeps nagging at me. If we accept the idea that the human mind uses rules of inference and has ontologies (relations between sets, subsets, part-of and other relations) to represent domains and knowledge then a natural question is how can such formalisms be represented in neural networks? The EP stuff I've been reading is filled with examples of various rules that are hypothesized to be part of the modular structure of the human mind as well as ontologies to represent things like kinds of animals, physical objects, social hierarchies, etc.

Really this question probably belongs more in general science because what I'm most interested in is the question of representation in human neurons but I thought I would start here because more is probably known about how (if?) they can be represented in computer neural nets. I have a good background in AI but its from the standpoint of expert systems, ontologies, logic, etc. I'm familiar with the basics of neural nets and neurons and synapses but just the basics. From what little I know representing things like if-then rules or sets and subsets via neural nets is not a solved problem. I seem to remember Michael Arbib talking about the importance of representing frames which I think were roughly what I would think of as a set (if you are familiar with frame based environments such as KL-One, Loom, or OWL/Protege) but its just a vague memory and it was a long time ago that I heard Arbib present some of his work and I could be remembering it wrong. My other impression is that the connectionist researchers tend to be not so interested in representing this kind of stuff but again just an impression not sure how accurate that is. Any opinions, pointers to papers, etc. would be welcome. --MadScientistX11 (talk) 02:42, 2 December 2015 (UTC)[reply]

Connectionists have been interested in that, but so far their ideas have been pretty much untestable because of limits on our ability to observe brain activity. People like David Touretzky and Paul Smolensky have worked on schemes for using neural networks to represent high-level structure -- if you go to the Parallel Distributed Processing books edited by Rumelhart and McClelland you'll find a number of chapters addressing those issues; our article on parallel distributed processing gives a few more relevant references. Looie496 (talk) 12:03, 2 December 2015 (UTC)[reply]

IPv4 and IPv6

How can one convert between IPv4 and IPv6? Are there any IPv6 addresses that cannot be converted to IPv4? GeoffreyT2000 (talk) 04:20, 2 December 2015 (UTC)[reply]

IPv4 has only 2³² possible addresses, while IPv6 has 2¹²⁸ addresses. So, there's no way most of the IPv6 addresses could be converted to IPv4, unless you want many different IPv6 addresses to convert to the same IPv4 address. On the other hand, there's no reason why every IPv4 address can't be converted to an IPv6 address, by whatever method you choose. For example, if we were to phase out IPv4, such a conversion would be in order, so every IPv4 device could keep the same address under the new system. StuRat (talk) 06:00, 2 December 2015 (UTC)[reply]

Stateless_IP/ICMP_Translation specifies that IPv4 addresses can be mapped to IPv6 address that are 46 zero double-words, followed by ffff:0000, followed by the 8 bytes of the target IPv4 address. LongHairedFop (talk) 10:39, 2 December 2015 (UTC)[reply]

Does Excel (or its accomplices) change files if you just open them without saving?

Does any program of the MS Office package change the file that you opened for viewing only? Specially in Excel, would it change a number with leading zeros like 001, 002, ..., to 1, 2, ...? Or would it insert end-of-line characters or anything else? If the user does not press the save button, is he save from any automatic change? --Denidi (talk) 14:32, 2 December 2015 (UTC)[reply]

Not a technical expert, but from personal experience in a work context: if you open an Excel file created by a particular Version of Excel using a different Version, it may change some formatting automatically. Hopefully someone else can contribute a deeper and more informed answer. {The poster formerly known as 87.81.230.195} 185.74.232.130 (talk) 14:48, 2 December 2015 (UTC)[reply]

No, if you don't explicitly save, the file on disk should not be modified. It is possible that you will see unexpected things when you look at the display, but there should not be any alteration of the file stored on disk unless you specifically "save" it. You might get a warning when you try to close the program that changes will be lost, and an offer to save before exiting, but if you decline to do so, the file should stay the same as before. Looie496 (talk) 15:08, 2 December 2015 (UTC)[reply]

Excel is a presentation tool. It takes the file and decides how to show it to you. So, it can (and almost always will) change the information. It will round off numbers. It will change fonts if you don't have the font specified in the saved file. It will convert values to dates if they look like they might be dates. However, it doesn't change the actual file on the drive. 209.149.113.52 (talk) 15:30, 2 December 2015 (UTC)[reply]

If you open the file convert it to another format, and Excel saves it, then it changes the file. The same applies to Word. --Scicurious (talk) 19:25, 2 December 2015 (UTC)[reply]

If you are opening a text format like CSV in Excel, I believe the other answers here are correct: When you open a CSV file, Excel will make educated guesses about what number formats the text is using and show you the results of those conversions, but the file will only be modified if you save.

If you are opening an Excel workbook and notice the modified date of the file change, read this: Excel changes Modified date and time when you open the workbook. For some file formats and some versions of Excel, "when you open an Excel workbook, Excel writes the name of the current user to the header of the file. This is necessary so that other users receive the "file in use" notification." --Bavi H (talk) 01:55, 3 December 2015 (UTC)[reply]

Excel does change the file just by opening it, even if you don't save. To see for yourself in Windows, right-click on the spreadsheet and choose 'Properties.' Observe the modification date. Then, open the file without changing it and then observe the modification time again while the file is open. Note that it has changed. Likewise, you can observe that the MD5 checksum of the file will change after you open it. After you close the file, the modification time will return to the previous date, but the MD5 checksum will not. This is proof that Excel changes the file even if you close it without saving it.—Best Dog Ever (talk) 02:08, 3 December 2015 (UTC)[reply]

Share my Location

Until a few days ago whenever I opened Google Maps in my browser (Firefox) the default map would be one of Birmingham (UK), where I live. However, it has now started centring the map on Edinburgh, about 300 miles to the north. I haven't been able to figure out any way to correct this, but Googling the problem suggests my assumed location is based on my IP address. I have a fixed IP address, so I used Geolocate to check it out, and that says I am in London, 100 miles in the other direction! This is mad. I've trawled through endless help files without success. Does anyone know how I can get Google maps to recognise my correct location please?--Shantavira|^{feed me} 16:36, 2 December 2015 (UTC)[reply]

An extension (particularly one designed to enhance your privacy) may have blocked the geolocation API. Try starting Firefox in safe mode (which disables all extensions) to see if the problem persists. In addition, this extension says it allows you to manually set (whether accurately or deliberately otherwise) your location; I've not used it, so I'm not in a position to vouch for it. -- Finlay McWalterᚠTalk 17:00, 2 December 2015 (UTC)[reply]

How much of the accessible information is already indexed?

Has Google, Bing or Yahoo released any stats about the amount of web-pages already indexed and web-pages that exist? --Scicurious (talk) 19:39, 2 December 2015 (UTC)[reply]

I see claims in various places that Google indexed about 30 trillion pages as of 2014 (e.g. [1]). Re total pages (including unindexed pages), Deep web (search) is the Wikipedia article, but it looks like it could use some work. There is probably no way to reliably estimate the number of unindexed pages. -- BenRG (talk) 00:52, 3 December 2015 (UTC)[reply]

Firefox vs. Evercookie

I am very much unimpressed with Evercookie being something that would continue to seem like a viable business model. Still ... I understand that it would work with something like Chrome that is sold by an evil corporation and distributed mostly by drive-by download, but what about a real browser like Firefox?

As I understand, Firefox set to delete history on close (i.e. cookies) can delete the regular cookie and the Flash cookie. If cache is included to the history fields to delete, it should resist cache cookies -- not that I really understand how those work. I'm less clear on some of the more arcane things mentioned in the Evercookie article ... and in any case not too sure about my statements above.

As a bonus: why would a regularly updated copy of Firefox be meat for Panopticlick? Specifically, what is unusual about a user agent string like "Mozilla/5.0 (Windows NT 6.3; WOW64; rv:42.0) Gecko/20100101 Firefox/42.0", and is there a way to fix it? Likewise, how can a recently downloaded Shockwave Flash plug-in be incredibly unique?

N.B. despite frequent representations to the contrary, WMF is apparently not too reluctant to use such fancy hacking to help collect better data for its friends in the NSA. See Meta:2015 Community Wishlist Survey/Moderation and admin tools. Wnt (talk) 23:25, 2 December 2015 (UTC)[reply]

December 3