Wikipedia:Reference desk/Archives/Computing/2015 October 10

= October 10 =

Shockwave Flash
Shockwave Flash keeps crashing on my computer. I've downloaded new copies from the Adobe site, but it keeps doing the same thing: failing. Any advice? Thanks, Halcatalyst (talk) 03:23, 10 October 2015 (UTC)
 * Here is some famous advice: Thoughts on Flash. "Flash is no longer necessary to watch video or consume any kind of web content."  Uninstall it.  Avoid websites that depend on it.  You may be surprised to discover that almost all modern websites, including the ones that offer multimedia and video experiences, do not require Flash.
 * Nimur (talk) 06:01, 10 October 2015 (UTC)
 * In other words, you don't know how to fix his problem? They're trying to view a Flash movie and your suggestion won't allow them to watch it. You claim that they don't need it, but they obviously do need it to watch the movie in question. If you don't have anything meaningful to say, consider not participating in the conversation. Steve Jobs was an advertising and branding guru who excelled at stealing other people's ideas. He was not an expert in Flash by any means and the many inaccuracies in the page you linked to are a reflection of that.&mdash;Best Dog Ever (talk)
 * Well, you are free to draw your own conclusion. I strongly feel that Thoughts on Flash is good advice, which is what the original question sought.  "We also know first hand that Flash is the number one reason Macs crash."  That public statement was validated using detailed engineering analysis of factual data, conducted by a company that cares about improving quality and customer experience.  It is not an exaggeration to say that statisically, the single most serious way a user damages their own computer is by choosing to install Flash.  Installing and using the Flash software causes more Mac system crashes than any other type of malware, defective software, or any hardware problem.  These are the facts.  Executives of large, publically-traded corporations do not make such statements in a vacuum: the entire article was informed by a lot of research and thought.
 * Most importantly, in the five years that have intervened since that published statement, the multimedia ecosystem has shifted away from Flash even further. Which website or content is the OP trying to access?  Has the OP verified that Flash is actually required to access that content?  There is a very high probability that once Flash is uninstalled, the very same web content will be delivered to the user's web browser using a newer, more reliable technology.  In this particular instance, the best solution to the OP's problem is actually to avoid the broken software.
 * If you do wish to continue using Flash, you should file a bug report to Adobe to track each crash. Here is Adobe's aptly named "wish request" website for reporting bugs.  If you are lucky, your Flash Bug Report will be treated as a top-priority issue and may be resolved within a few years, provided that Adobe remembers to actually include the fix when they ship their product update.
 * Nimur (talk) 15:18, 10 October 2015 (UTC)
 * Fist, he wrote that in 2010. Today, all of the major browsers except Firefox run each browser tab in a separate process. (And the next release of Firefox will, too.) So, even if a poorly-written Flash movie locks up the plugin, the parent browser process should continue to work. Further, if the entire Mac OS operating system "crashes" (i.e., has a kernel panic) because of a browser plugin, then that is really an indictment of the stability of the Mac OS. I use Windows and Linux and I have never seen this happen in those operating systems. Further, in terms of crashes, you could say the same things about other Web technologies like JavaScript and even static images. I have seen Web pages lock up because of poorly-written JavaScript and even HTML tags. I have to use the Flash player every day on certain sites I visit. I'm not even sure if what he said was true in 2010 because his own company's QuickTime plugin along with the Java plugin had far more issues than Flash, but it definitely shouldn't be an issue today.&mdash;Best Dog Ever (talk) 22:10, 10 October 2015 (UTC)
 * I would fall in between in this debate, personally I've found Flash can often cause problems, particularly advertisements using Flash, but I also agree JavaScript and other aspects of poorly written websites can be problematic. Flash is also a common security risk, although I do agree it should be exceedingly rare that it will crash the entire operating system, not least because the biggest risk is from more professional criminals threats who want to use the security flaws to their advantage, not cause OS crashes (well unless they need that to do whatever they want to do). I do agree that Nimur is overestimating how easy it is to get away with Flash though. While it's true many websites now have HTML5 video, many do not. In fact, just today I found out Periscope still requires Flash for their website. Evidentally (and a test seems to confirm this is correct), so does Meerkat. Both of these services were highly targeted at mobile users, so I presume this is partially because they expect mobile users to use their apps, and the website streaming was more of a secondary consideration but it still illustrate the limitations. Edit: Affecting desktop users who would prefer not to use Flash who often won't have an easy way to use a standalone app even if they wanted to, since the Windows app store is still fairly moribund so even that crossover often doesn't help. But also mobile users who just want to stream and can't be bothered with installing their thousandth app because everyone wants you to use their app. So I'm not saying I like the current Flash situation, which includes Adobe giving up on Flash even for Android. And in case you're wondering, the reason I found out about Periscope wasn't because I was looking to watch some random lifecaster, but for what I think may have been the only live broadcast (including broadcast TV) of a NZ police media conference .  Actually that sort of app centric model seems to be fairly common, I believe two or possibly all 3 of NZ's public TV catchup services still require Flash. They have mobile apps for at least some platforms, but no HTML5 on their website. (Some other websites added HTML5 on their mobile websites but still require Flash for their non mobile ones.) I've seen a number of news websites, both NZ and elsewhere likewise still require Flash. Getting back to Meerkat and Periscope, I think another reason is because HTML5 Video isn't really designed for live streaming (see  and  for example). Apple's HTTP Live Streaming is one answer, MPEG-Dash and I think there are various ways you can probably support most browsers although it may require more than one solution. Frankly MPEG Dash seems the better solution, but Apple is refusing to support it instead only supporting HLS to the extent all apps submitted to their store need to use it, but then they also seemingly abandoned their plans to standarise HLS after 2009. Some of these are old but see   .) So live streams are one area where support tends to be more limited. Other than Meerkat & Periscope, I believe the Reserve Bank of NZ also does for their live webcasts . (Although they're also available via some other platforms so it's possible some of these don't need Flash.) Al Jazeera seems to have an alternative player, but for some reason it didn't work on either Chrome or Firefox for me . It could be the geoblock was broken. Anyway even Youtube only added HTML5 for live streaming in May this year, although to be fair, they only really started to concentrate on the service recently when they decided they wanted to compete with Twitch for live streaming computer games. Twitch likewise is still only recently started to properly support non Flash  . I think a combination of reasons has meant live streaming without Flash is probably getting a lot better both on desktops and on mobiles, see the earlier links and also    , so perhaps in 3 years or so, we'll be where we are now with live-streaming with static HTML 5 videos. BTW, a number of gaming websites also require Flash, if you're into that sort of thing.  In fact there are a number of fairly famous indie titles on Steam that use builtin Flash. (Others may have been made for Flash, but use some sort of more standalone Adobe Air environment.) Edit: I should clarify that the Steam point is obviously unrelated to whether your need Flash on the browser, instead more to point out that a number of people are still finding it an acceptable way to release a game. Although some of these Steam titles are available in some form online as Flash games outside Steam. Anecdotally, I nearly always have Flash BTW, since I don't use mobile devices anywhere as much as I used to and the only time my desktop doesn't have Flash is when I just installed a new OS or something similar and didn't bother to install Flash yet, yet even with that I still notice problems from not having Flash. (Although admitedly I do have a tendency to sometimes hunt for videos, such as finding one that isn't censored or is more complete on news websites.) If you're only using major websites perhaps you won't miss Flash, particularly if you don't care about live content. If you regularly use less major ones or happen to use one which does require Flash, you may not be so lucky, particularly if you prefer the content to be there (since it can happen at the oddest of times), and aren't the sort of person who'd just go, "well their loss". It's been over 5 years since the iPad was launched in 2010, over 7 years since the iOS app store in 2008 (App Store (iOS)), nearly 7 years since the first commercial Android device also in 2008 (Android (operating system) or HTC Dream) and nearly 4 years since Adobe confirmed they'd basically abandoned Flash in the mobile space completely  and while it's obviously a lot easier to be Flash free now, this long tail of websites which still use Flash for something, is still there. I suspect the long tail is going to be there for a long time more, not helped by the current live streaming mess, which let's not forget appears to be partially because the company that was the lifework of the person who's advice was quoted above who made a big deal about about openness; refuses to use or accept the only international standard, and also has seemingly decided to leave the system they require be mired as a somewhat regularly updated draft forever. (Nothing that unique about this of course, many companies either don't really care about openness; or claim they do, until it's something which conflicts with some goal, plan or they simply can't be bothered.) Probably the inability to agree on a video codec to use given the patent vs royalty free open source mess hasn't helped HTML5 either. Nil Einne (talk) 04:39, 13 October 2015 (UTC), edits marked as edit: at 15:42, 13 October 2015 (UTC)


 * I recommend trying a different Web browser. Different Web browsers have their own version of the Flash player. For example, if you're trying to view it using Internet Explorer, try viewing the movie in Firefox. If you're using Firefox, try IE, etc.&mdash;Best Dog Ever (talk) 08:05, 10 October 2015 (UTC)

I appreciate your technical discussion, and I did read and understand "Thoughts on Flash." However, except for that (which is something, because I enjoy learning things), I'm no farther ahead.

I don't want to use Flash. I had heard before that it sucked, but I don't know what to use in its place.

I'm using the latest version of Firefox; this is where the error messages keep appearing. Halcatalyst (talk) 23:47, 10 October 2015 (UTC)


 * Which Web page is having the issue? Can you provide us a link?&mdash;Best Dog Ever (talk) 00:09, 11 October 2015 (UTC)


 * Many, many, many. Firefox has been my main browser for a long time. I'm on the Internet a lot, in lots of different places, almost always with Firefox, and these errors occur at least once an hour. Halcatalyst (talk) 01:31, 11 October 2015 (UTC)


 * Can you please give at least one example?&mdash;Best Dog Ever (talk) 03:09, 11 October 2015 (UTC)
 * Firefox supports HTML5 video, including webm and H.264 formats. If you were using Flash to watch video, there is a very strong chance that you can watch the same video using Firefox (with no required add-ons or plugins) after uninstalling Flash.
 * Nimur (talk) 15:35, 11 October 2015 (UTC)


 * I've removed Flash and now will wait to see if the problem reoccurs. I'm optimistic that it won't. If it does, I'll start a new topic. Thank you, all. Halcatalyst (talk) 16:31, 12 October 2015 (UTC)


 * I'm running Flash without any problems, but I'd be interested in seeing whether I actually need to uninstall it to use the browser's native support, or whether it is sufficient to disable it or configure the browser to "always ask" before running the Flash add-on (which is my usual configuration). The browser is Pale Moon, but I could also test with Firefox. To that end could somebody please provide a specific example of a web page with content (eg video) that uses Flash if Flash is installed, but works without Flash if Flash is not installed. 165.225.98.89 (talk) 00:31, 13 October 2015 (UTC)
 * For example, see YouTube HTML5 Video Player. Google's servers will deliver Flash video if your browser reports Flash is installed.  If you disable Flash, or remove it, Google's servers will deliver the same video in an HTML5-compliant form.  Nimur (talk) 02:31, 13 October 2015 (UTC)
 * So far as I can see, https://www.youtube.com/html5 does not contain any video or similar material that invokes Flash (when Flash is enabled). Can I please have a specific example of a web page with content (eg video) that uses Flash if Flash is installed, but works without Flash if Flash is not installed. 165.225.98.89 (talk) 23:31, 13 October 2015 (UTC)
 * Look closer, and inspect the HTTP headers sent by your browser. You may be underestimating the ability of the server to modify the web-content that it delivers to your browser.  You may find Live Headers and Modify Headers to be useful for these kinds of investigations on the Firefox platform.  Nimur (talk) 18:47, 14 October 2015 (UTC)
 * An answer for the less technical user would be helpful. Could someone please provide a specific address for a web page that uses Flash, when Flash is installed, but does not actually require it. I don't want to "inspect the HTTP headers", I want to do a simple, non-technical demonstration, eg go to the nominated web page, see that Flash runs, then disable or uninstall Flash, go to the same web page and see the video (or whatever) work without Flash. Presumably if "almost all modern websites, including the ones that offer multimedia and video experiences, do not require Flash" it ought not be to hard for someone to provide a specific example of one. Thank-you 165.225.98.89 (talk) 23:39, 14 October 2015 (UTC)
 * https://www.youtube.com/html5 - this specific URL, in addition to nearly all other content on the YouTube webpage, including most of the videos - will use Flash, if Flash is installed; and will work without Flash, if Flash is not installed, on modern browsers (including recent versions of Mozilla Firefox). Nimur (talk) 21:53, 15 October 2015 (UTC)

almost duplicate file detector
On computers there is often a "duplicate file" utility that scans and deletes duplicates. Is there any such utility that scans for almost-duplicate files? Say for example two text files that are identical except for one letter. A duplicate file finder would not detect them because the are not identical. I need something that can detect files that are 99% the same. Thanks — Preceding unsigned comment added by 91.225.109.63 (talk) 10:19, 10 October 2015 (UTC)


 * I'm not sure about deleting files, but if you want to save space, maybe a file compression utility will help you. Here's the situation where I use a file compressor. If your situation is similar maybe it will help you too:


 * When I am working on a file, I often make copies of my progress in case I ever want to go back to a previous version. When I'm done with the file, I compress all the in-progress versions into a single archive. The archive utility I use is able to recognize the duplicate parts of the files and only save them once. Specifically, I use 7-Zip with the "solid block size" set to the maximum "solid" setting. This "solid block" setting tells the compressor to compress all the files together instead of compressing each file separately. You may need to make sure the file compressor you use has a "solid" setting like this.


 * --Bavi H (talk) 15:14, 10 October 2015 (UTC)

I don't want to keep the almost-duplicate files, I want to delete them. Thanks 91.225.109.63 (talk) 15:57, 10 October 2015 (UTC)

→Comparison of file comparison tools -- Hans Haase (有问题吗) 11:23, 11 October 2015 (UTC)


 * I assume you are wing Windows. In Linux, this is a command-line task. If you want to know how different two files are, you can use diff. If you want to know how similar two files are, you can use comm. You can tweak both to get exactly what you want (e.g. How many lines are in one but not the other). Then, from that output, you can do a count with wc. You can wrap that in an if less-than to find pairs of files where the count of differences is less than a set number of differences. You wrap that in find to find files and compare to other files, deleting when the if condition is true. I can understand it that someone might turn all that into a single shell script, but I don't see why anyone would waste time writing a program to do all the major tasks that are already done. 75.139.70.50 (talk) 21:37, 12 October 2015 (UTC)
 * Can you post the command and pipes to do all that? I have most unix tools on Windows but I don't know how to use them in such an advanced way. Thanks 91.225.109.63 (talk) 11:47, 13 October 2015 (UTC)


 * There is actually a clue in the other answers. If you have a good compression algorithm compressing files pairwise would give much better compression for near-duplicates.  You could then rank the pairs and decide which to delete.
 * But really the question is open ended. If you are looking for files that "differ by one (or n) characters"  say "x" replaced by "y" then the place to start is files of the same length.
 * However consider "xxxxxxxxx" and "xxxxxxxxxxxxxxxxxxxxxxxxxxxx"  arguably these are very similar (1 million "x"s and 1,000,100 "x"s could be considered "more similar" or "less similar")  would you want to keep one or both?
 * All the best: Rich Farmbrough, 17:25, 13 October 2015 (UTC).

Does the US government use any computer made abroad?
The ISS uses Lenovo ThinkPads, aren't these made in China? Are there other computers made abroad and used by the US gov, for essential or non-essential tasks? --YX-1000A (talk) 17:20, 10 October 2015 (UTC)
 * The short answer is "yes," and the long answer is that policy for procurement of commercial products (like computers and computer software) is very complex for a massive institution like the United States Government. You can start by reading acquisition.gov, a website managed by the General Services Administration of the Federal Government.  That website helps government employees, particularly Contracting Officers, navigate the Federal Acquisition Regulations, a part of the Code of Federal Regulations that define rules for Government purchases.  Among the many factors to consider are concepts like "full and open competition," which is sometimes but not always mandatory; those regulations mean that a foreign vendor may or may not bid for a specific procurement contract.  To confound the issue, it is difficult to define "Made in the USA" for a complex technology product like a computer.
 * You can see our main article, Government procurement in the United States, for additional information.
 * You can also see what the Federal Trade Commission has to say about "Made in USA" at Complying with the Made in USA Standard. Several of their examples relate what is and what is not acceptable with respect to claiming a "computer" is "Made in USA" or "Assembled in USA."  Generally, computers sold in the United States do not need to disclose anything about where they are made, because American Federal regulations mandating "must disclose" product origin generally only apply to automobiles and textile, wool, and fur products.  (There is some debate regarding Country of Origin Labeling for agricultural products - some Federal laws mandate COOL labeling, while other rulings by Department of Justice refer to treaties that mandate non-labeling.)  In summary: some government procurement contracts may mandate preferential treatment for American computers; others may mandate non-discrimination against any bidder based on the product's country of origin.
 * If you think these confusing regulations gets any simpler in the case of Department of Defense acqusitions: think again. Here's the Defense Procurement Agency website on International Contractors.  Perhaps more than any other Federal agency, DoD has to conduct significant operations - and therefore, must procure significant materiel - outside of the borders of the United States.  Add the extra complexity of International Traffic in Arms Regulation, and added requirements for security and accountability, and what you have is a very solid, guaranteed future-career-path for military lawyers and procurement officers.
 * Nimur (talk) 17:40, 10 October 2015 (UTC)
 * Nimur, apologies if I'm misreading, but your answer seems directed to a question about economics and nationalism ("are we supporting American jobs?"). My take on the OP's question is that it's more security-related ("has the Chinese government added malicious logic at the hardware or firmware level?").  --Trovatore (talk) 18:06, 10 October 2015 (UTC)
 * I understand that such a concern would obviously exist. My understanding of the procurement policy is that questions about supplier integrity are independent from questions about supplier's nation of origin (if for no other reason, because such a concern about nation of origin would be discriminatory, and if a Federal employee acted on such discrimination, their action might be illegal).
 * In other words, "did they put malware in our product?" is legally a distinct question, and must normally be handled in complete isolation from the secondary question, "are they from China?"
 * Nimur (talk) 18:09, 10 October 2015 (UTC)
 * So far I understood that it's OK to discriminate a product or service for its origin. That would be a completely scenario of discriminating against a job seeker. Shouldn't the US gov or any other US company be allowed to avoid buying goods from China, or from a company located on a tax haven, or from a country which could hang sanctions against the US? You could prefer to buy a German car instead of a Korean car for quite good reasons (maybe, since the VW scam, not anymore, but you get the idea). Jubilujj 2015 (talk) 18:38, 10 October 2015 (UTC)
 * No... the United States is a member of the World Trade Organization and a signatory of several treaties exactly relating to this type of thing. In other words, these agreements guarantee that for the most part, our government will not discriminate for or against a product or service  based on its country of origin.  There are a very small number of exceptions, but that is the broad policy.  Nimur (talk) 19:12, 10 October 2015 (UTC)
 * For more reading on this topic, see also: Buy American Act legislation, from 1933, and its complex relationship to newer trade agreements, including the Agreement on Government Procurement (1996, revised 2014).
 * Among the informative articles I have found is The Berry Amendment: Requiring Defense Procurement to Come from Domestic Sources, published by the Congressional Research Service and hosted at the website of the Federation of American Scientists.
 * By some, where DOD purchases its berets is viewed as a relatively minor matter, when compared to where it purchases its electronics; specialty metals; and other hardware used for logistics support, communications, and weapons modernization. However, to others small businesses’ loss of such a contract to foreign sources can be seen as unacceptable.
 * This report does a fantastic job explaining how all of these trade policies interconnect.
 * Although foreign sourcing of materiel may constitute a security risk, many economists believe that economic protectionism constitutes an even bigger security risk: "When goods cannot cross borders, armies will." It is not clear which school of thought is actually correct, especially as we enter this era of prolific global trade driven by cheap transportation and sophisticated technological goods.
 * Nimur (talk) 17:31, 11 October 2015 (UTC)

OP fear of "outsourced skynet" doomsday scenerio shown in black ops 2, made real by xiaomei device. Use peerblock, do not look at blinding flash, stock up on antipsychoticsMahfuzur rahman shourov (talk) 15:50, 15 October 2015 (UTC)