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• Card deck and sparse matrix interview questions

  - by MrDatabase

  I just had a technical phone screen w/ a start-up. Here's the technical questions I was asked ... and my answers. What do think of these answers? Feel free to post better answers :-) Question 1: how would you represent a standard 52 card deck in (basically any language)? How would you shuffle the deck? Answer: use an array containing a "Card" struct or class. Each instance of card has some unique identifier... either it's position in the array or a unique integer member variable in the range [0, 51]. Shuffle the cards by traversing the array once from index zero to index 51. Randomly swap ith card with "another card" (I didn't remember how this shuffle algorithm works exactly). Watch out for using the same probability for each card... that's a gotcha in this algorithm. I mentioned the algorithm is from Programming Pearls. Question 2: how to represent a large sparse matrix? the matrix can be very large... like 1000x1000... but only a relatively small number (~20) of the entries are non-zero. Answer: condense the array into a list of the non-zero entries. for a given entry (i,j) in the array... "map" (i,j) to a single integer k... then use k as a key into a dictionary or hashtable. For the 1000x1000 sparse array map (i,j) to k using something like f(i, j) = i + j * 1001. 1001 is just one plus the maximum of all i and j. I didn't recall exactly how this mapping worked... but the interviewer got the idea (I think). Are these good answers? I'm wondering because after I finished the second question the interviewer said the dreaded "well that's all the questions I have for now." Cheers!

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• Salt River Project Identifies US$500,000 in Cost Reduction Opportunities Through Unified IT Portfolio Management

  - by Melissa Centurio Lopes

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Salt River Project (SRP) includes two entities serving the Phoenix area: the Salt River Project Agricultural Improvement and Power District and the Salt River Valley Water Users’ Association. The SRP district operates various power plants and generating stations to provide electricity to nearly 956,000 retail customers. The SRP association maintains an extensive system of reservoirs, wells, and irrigation laterals to deliver nearly 1 million acre-feet of water annually. Salt River Project implemented Oracle’s Primavera Portfolio Management to unify management of its extensive IT portfolio, including essential utility systems, like work and asset management, as well as programming frameworks and development tools. With the system, SRP discovered almost US$500,000 in cost-reduction opportunities by identifying redundant or low use software, including 150 applications that are close to being unsupported. The company retired 10 applications in the last year and upgraded 34 systems. SRP also identified preferred technologies and ensured that more than 90% of applications are based on standard technologies—reducing procurement costs, simplifying maintenance support, and lowering total cost of ownership. Solutions: Provided approximately 70 users in the IT support group with detailed insight into the product lifecycle of each piece of IT infrastructure and software in the entire portfolio Discovered almost US$500,000 in cost reduction opportunities by identifying redundant or low use software that could be eliminated or migrated to alternative solutions Identified approximately 150 applications that are close to being unsupported and prioritized them to begin modernization Click here to view more Oracle Primavera Portfolio Management solutions for SRP. Why Oracle Salt River Project chose Oracle’s Primavera Portfolio Management after evaluating it against four other solutions. “Oracle’s Primavera Portfolio Management offered the most functionality to support our diverse needs,” said Eileen Ahles, IT portfolio manager, Salt River Project. Read the complete customer success story Access a list of all Primavera customer success stories

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• Getting Started with Kinect for Windows.

  - by Vishal

  Hello folks,      Recently I got involved in a project for building a demo application for one of our customers with Kinect for Windows. Yes, something similar what Tom Cruise did in the movie Minority Report. Waving arms, moving stuff around, swipes, speech recognition, manipulating computer screens without even touching it. Pretty cool!!! The idea in the movie showed us how technology would be after 50 years from that day.   Minority Report Movie clip.           Well, that 50 years of time frame got squeezed and recently on Feb 1st 2012, Microsoft released the official Kinect for Windows SDK. That’s just 10 years from the movie release. Although, the product is in it early stages but with developer creativity and continuously improving hardware, those features shown in the movie are not very far away from becoming a reality. Soon after releasing the SDK, Microsoft again announced in March the release of its new Kinect for Windows SDK version 1.5 which is coming out in sometime May. More history about Kinect. Anyways, so for a newbie with Kinect, where would you start. Here is what I would suggest you can do. Watch the Kinect for Windows Quick start Series by Den Fernandez. Download the Kinect for Windows SDK and start playing around with the demos in it. It also comes with some basic Kinect documentation. Coding4Fun Kinect Projects | Lot many more videos and open sources projects information. Kinect for Windows Session at Techdays NL demo by Jesus Rodriguez. Book: Beginning Kinect Programming with the Microsoft Kinect SDK.  | I did go through few of the chapters in this book and based on that, it does talk deeply about core Kinect concepts but in very easy to understand way. I would definitely suggest this book for any Kinect developers. I liked the way it explained the Gestures recognition in Chapter 6. Buy your Kinect device from either Amazon or NewEgg. You will get it cheaper then buying it from Microsoft Store. Personally, I love Newegg.com as I never had any order related or shipping issues with them. I always hate developing UI application but well, you would need to get your hands dirty with WPF too in order to work with Kinect. So get started with WPF concepts too. I will keep adding stuff to the list once I come across them but so far the above list would definitely get you started building your first Kinect apps. Till then Happy Kinecting…!!!!! Thanks, Vishal Mody

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• Using lookahead assertions in regular expressions

  - by Greg Jackson

  I use regular expressions on a daily basis, as my daily work is 90% in Perl (legacy codebase, but that's a different issue). Despite this, I still find lookahead and lookbehind to be terribly confusing and often unreadable. Right now, if I were to get a code review with a lookahead or lookbehind, I would immediately send it back to see if the problem can be solved by using multiple regular expressions or a different approach. The following are the main reasons I tend not to like them: They can be terribly unreadable. Lookahead assertions, for example, start from the beginning of the string no matter where they are placed. That, among other things, can cause some very "interesting" and non-obvious behaviors. It used to be the case that many languages didn't support lookahead/lookbehind (or supported them as "experimental features"). This isn't the case quite as much, but there's still always the question as to how well it's supported. Quite frankly, they feel like a dirty hack. Regexps often already are, but they can also be quite elegant, and have gained widespread acceptance. I've gotten by without any need for them at all... sometimes I think that they're extraneous. Now, I'll freely admit that especially the last two reasons aren't really good ones, but I felt that I should enumerate what goes through my mind when I see one. I'm more than willing to change my mind about them, but I feel that they violate some of my core tenets of programming, including: Code should be as readable as possible without sacrificing functionality -- this may include doing something in a less efficient, but clearer was as long as the difference is negligible or unimportant to the application as a whole. Code should be maintainable -- if another programmer comes along to fix my code, non-obvious behavior can hide bugs or make functional code appear buggy (see readability) "The right tool for the right job" -- I'm sure you can come up with contrived examples that could use lookahead, but I've never come across something that really needs them in my real-world development work. Is there anything that they're really the best tool for, as opposed to, say, multiple regexps (or, alternatively, are they the best tool for most cases they're used for today). My question is this: Is it good practice to use lookahead/lookbehind in regular expressions, or are they simply a hack that have found their way into modern production code? I'd be perfectly happy to be convinced that I'm wrong about this, and simple examples are useful for examples or illustration, but by themselves, won't be enough to convince me.

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• Explanation of the definition of interface inheritance as described in GoF book

  - by Geek

  I am reading the first chapter of the Gof book. Section 1.6 discusses about class vs interface inheritance: Class versus Interface Inheritance It's important to understand the difference between an object's class and its type. An object's class defines how the object is implemented.The class defines the object's internal state and the implementation of its operations.In contrast,an object's type only refers to its interface--the set of requests on which it can respond. An object can have many types, and objects of different classes can have the same type. Of course, there's a close relationship between class and type. Because a class defines the operations an object can perform, it also defines the object's type . When we say that an object is an instance of a class, we imply that the object supports the interface defined by the class. Languages like c++ and Eiffel use classes to specify both an object's type and its implementation. Smalltalk programs do not declare the types of variables; consequently,the compiler does not check that the types of objects assigned to a variable are subtypes of the variable's type. Sending a message requires checking that the class of the receiver implements the message, but it doesn't require checking that the receiver is an instance of a particular class. It's also important to understand the difference between class inheritance and interface inheritance (or subtyping). Class inheritance defines an object's implementation in terms of another object's implementation. In short, it's a mechanism for code and representation sharing. In contrast,interface inheritance(or subtyping) describes when an object can be used in place of another. I am familiar with the Java and JavaScript programming language and not really familiar with either C++ or Smalltalk or Eiffel as mentioned here. So I am trying to map the concepts discussed here to Java's way of doing classes, inheritance and interfaces. This is how I think of of these concepts in Java: In Java a class is always a blueprint for the objects it produces and what interface(as in "set of all possible requests that the object can respond to") an object of that class possess is defined during compilation stage only because the class of the object would have implemented those interfaces. The requests that an object of that class can respond to is the set of all the methods that are in the class(including those implemented for the interfaces that this class implements). My specific questions are: Am I right in saying that Java's way is more similar to C++ as described in the third paragraph. I do not understand what is meant by interface inheritance in the last paragraph. In Java interface inheritance is one interface extending from another interface. But I think the word interface has some other overloaded meaning here. Can some one provide an example in Java of what is meant by interface inheritance here so that I understand it better?

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• The Faces in the Crowdsourcing

  - by Applications User Experience

  By Jeff Sauro, Principal Usability Engineer, Oracle Imagine having access to a global workforce of hundreds of thousands of people who can perform tasks or provide feedback on a design quickly and almost immediately. Distributing simple tasks not easily done by computers to the masses is called "crowdsourcing" and until recently was an interesting concept, but due to practical constraints wasn't used often. Enter Amazon.com. For five years, Amazon has hosted a service called Mechanical Turk, which provides an easy interface to the crowds. The service has almost half a million registered, global users performing a quarter of a million human intelligence tasks (HITs). HITs are submitted by individuals and companies in the U.S. and pay from $.01 for simple tasks (such as determining if a picture is offensive) to several dollars (for tasks like transcribing audio). What do we know about the people who toil away in this digital crowd? Can we rely on the work done in this anonymous marketplace? A rendering of the actual Mechanical Turk (from Wikipedia) Knowing who is behind Amazon's Mechanical Turk is fitting, considering the history of the actual Mechanical Turk. In the late 1800's, a mechanical chess-playing machine awed crowds as it beat master chess players in what was thought to be a mechanical miracle. It turned out that the creator, Wolfgang von Kempelen, had a small person (also a chess master) hiding inside the machine operating the arms to provide the illusion of automation. The field of human computer interaction (HCI) is quite familiar with gathering user input and incorporating it into all stages of the design process. It makes sense then that Mechanical Turk was a popular discussion topic at the recent Computer Human Interaction usability conference sponsored by the Association for Computing Machinery in Atlanta. It is already being used as a source for input on Web sites (for example, Feedbackarmy.com) and behavioral research studies. Two papers shed some light on the faces in this crowd. One paper tells us about the shifting demographics from mostly stay-at-home moms to young men in India. The second paper discusses the reliability and quality of work from the workers. Just who exactly would spend time doing tasks for pennies? In "Who are the crowdworkers?" University of California researchers Ross, Silberman, Zaldivar and Tomlinson conducted a survey of Mechanical Turk worker demographics and compared it to a similar survey done two years before. The initial survey reported workers consisting largely of young, well-educated women living in the U.S. with annual household incomes above $40,000. The more recent survey reveals a shift in demographics largely driven by an influx of workers from India. Indian workers went from 5% to over 30% of the crowd, and this block is largely male (two-thirds) with a higher average education than U.S. workers, and 64% report an annual income of less than $10,000 (keeping in mind $1 has a lot more purchasing power in India). This shifting demographic certainly has implications as language and culture can play critical roles in the outcome of HITs. Of course, the demographic data came from paying Turkers $.10 to fill out a survey, so there is some question about both a self-selection bias (characteristics which cause Turks to take this survey may be unrepresentative of the larger population), not to mention whether we can really trust the data we get from the crowd. Crowds can perform tasks or provide feedback on a design quickly and almost immediately for usability testing. (Photo attributed to victoriapeckham Flikr While having immediate access to a global workforce is nice, one major problem with Mechanical Turk is the incentive structure. Individuals and companies that deploy HITs want quality responses for a low price. Workers, on the other hand, want to complete the task and get paid as quickly as possible, so that they can get on to the next task. Since many HITs on Mechanical Turk are surveys, how valid and reliable are these results? How do we know whether workers are just rushing through the multiple-choice responses haphazardly answering? In "Are your participants gaming the system?" researchers at Carnegie Mellon (Downs, Holbrook, Sheng and Cranor) set up an experiment to find out what percentage of their workers were just in it for the money. The authors set up a 30-minute HIT (one of the more lengthy ones for Mechanical Turk) and offered a very high $4 to those who qualified and $.20 to those who did not. As part of the HIT, workers were asked to read an email and respond to two questions that determined whether workers were likely rushing through the HIT and not answering conscientiously. One question was simple and took little effort, while the second question required a bit more work to find the answer. Workers were led to believe other factors than these two questions were the qualifying aspect of the HIT. Of the 2000 participants, roughly 1200 (or 61%) answered both questions correctly. Eighty-eight percent answered the easy question correctly, and 64% answered the difficult question correctly. In other words, about 12% of the crowd were gaming the system, not paying enough attention to the question or making careless errors. Up to about 40% won't put in more than a modest effort to get paid for a HIT. Young men and those that considered themselves in the financial industry tended to be the most likely to try to game the system. There wasn't a breakdown by country, but given the demographic information from the first article, we could infer that many of these young men come from India, which makes language and other cultural differences a factor. These articles raise questions about the role of crowdsourcing as a means for getting quick user input at low cost. While compensating users for their time is nothing new, the incentive structure and anonymity of Mechanical Turk raises some interesting questions. How complex of a task can we ask of the crowd, and how much should these workers be paid? Can we rely on the information we get from these professional users, and if so, how can we best incorporate it into designing more usable products? Traditional usability testing will still play a central role in enterprise software. Crowdsourcing doesn't replace testing; instead, it makes certain parts of gathering user feedback easier. One can turn to the crowd for simple tasks that don't require specialized skills and get a lot of data fast. As more studies are conducted on Mechanical Turk, I suspect we will see crowdsourcing playing an increasing role in human computer interaction and enterprise computing. References: Downs, J. S., Holbrook, M. B., Sheng, S., and Cranor, L. F. 2010. Are your participants gaming the system?: screening mechanical turk workers. In Proceedings of the 28th international Conference on Human Factors in Computing Systems (Atlanta, Georgia, USA, April 10 - 15, 2010). CHI '10. ACM, New York, NY, 2399-2402. Link: http://doi.acm.org/10.1145/1753326.1753688 Ross, J., Irani, L., Silberman, M. S., Zaldivar, A., and Tomlinson, B. 2010. Who are the crowdworkers?: shifting demographics in mechanical turk. In Proceedings of the 28th of the international Conference Extended Abstracts on Human Factors in Computing Systems (Atlanta, Georgia, USA, April 10 - 15, 2010). CHI EA '10. ACM, New York, NY, 2863-2872. Link: http://doi.acm.org/10.1145/1753846.1753873

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• Preview Links and Images in Google Chrome

  - by Asian Angel

  Anyone who has used the CoolPreviews extension in Firefox knows how wonderful that preview window can be. Now you can get the same kind of functionality in Chrome with the ezLinkPreview extension. Note: Extension will not work on websites containing “frame buster” code (navigation to the actual URL will occur). Before Normally if you want to have a better look at a particular webpage the only option you have is to go ahead and open it in a new tab or window. But it would certainly be nice to be able to take a quick “sneak peek” before-hand… After As soon as you have finished installing the extension everything is ready to go…just refresh any pages open prior to installation and enjoy the preview goodness. When you hover your mouse near any link you will notice a small “Preview Button” appear with the letters “EZ” inside. A closer look at the “Preview Button”. Click on the “Preview Button” to open the popup window. Now you can get a very good idea of whether the page is worth visiting or not. Here is a closer look at the popup window. Notice that you can see the URL for the webpage and access a convenient set of buttons on the right side (Open to new tab, Pin to keep overlay open, and Close). You can even resize the window as desired to best suit your needs (you can actually grab any of the four corners to resize the popup window). It is also possible to open a “preview window” inside the popup window…you can see the “Preview Button” here… If you have Chrome maximized you can enjoy using a large sized “preview window”. Now that is nice! For those who may be curious you can see that ezLinkPreview works nicely with images too. Conclusion The ezLinkPreview extension provides a quick and simple way to preview links and/or images while you are browsing. If you are looking for similar functionality in Firefox then be sure to read our article on CoolPreviews here. Links Download the ezLinkPreview extension (Google Chrome Extensions) Similar Articles Productive Geek Tips Google Image Search Quick FixSubscribe to RSS Feeds in Chrome with a Single ClickFind a Website’s Actual Location with Chrome FlagsHow to Make Google Chrome Your Default BrowserEnable Auto-Paging Goodness in Google Chrome TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 QuicklyCode Provides Cheatsheets & Other Programming Stuff Download Free MP3s from Amazon Awe inspiring, inter-galactic theme (Win 7) Case Study – How to Optimize Popular Wordpress Sites Restore Hidden Updates in Windows 7 & Vista Iceland an Insurance Job?

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• Moving users folder on Windows-7 to another partition - bad idea?

  - by Donat

  Hi, I'd like to re-submit here a question posted by Benjol on Aug 17at 5:57 "Moving users folder on Windows Vista to another partition - bad idea?" (I can't post one than one link until I earn "10 reputation" and removed my "answer" there to post my follow-up questions here). I am anxiously getting ready at long last to to carry out a clean install (using custom install option) from Vista to Windows-7 Home Premium 64bit with the free upgrade I received late October. For my Vista system I successfully set-up last Summer a multi-partitions scheme with Users and Program Data on a a different partition than the operating system (see link below, and its subsequent links in my comment for details). http://tuts4tech.net/2009/08/05/windows-7-move-the-users-and-program-files-directories-to-a-different-partition/comment-page-1/#comment-562 I was planning a similar set-up for windows 7, a little more streamlined, with OS, Program Files on C:, Users and Program Data on D:, and TV media recording on a separate partition. Reading the Question submitted by Benjol, I am second guessing too. Is moving Users and Program Data on a different partition than the default primary partition with OS and Program Files such a good idea? The couple of people I talked to at the official Microsoft Windows 7 booth at CES 2010 gave the same answer to the intention of moving the Users profile folder to another partition. In a nutshell, they all told me that they used to do this in XP and less in Vista but not anymore with Windows 7... "It is stable, after two months still no problem" I had the feeling it was a scripted answer to emphasize how Windows 7 is so stable and efficient... (Will Windows-7 system not become bugged down over the course of several months to a year or two? Only time will tell) Long story short, I share the same view than Benjol expressed with respect to being "able to backup and restore system and user data independently." I just received a 2TB usb2, eSATA external hard drive as a back-up drive, which includes NTI Shadow 4 (4.1.0.150) for back-up solution. I took note of the issue with NTUSER.DAT and I will read more about Volume Shadow Copy Service (VSS) for Windows 7. I am willing to put the effort if placing Users and Program Data on a different partition would allow to restore a fresher OS+Program image when the system gets bugged down. Questions: Is it such a bad idea? What is the "easy route" referred by Benjol in his post? Is it to just relocate folders to another partition using the Folder property tool? (It is not practical for several users and might not provide a straightforward restore process of just OS and Program Files when needed.) I am starting to learn about Windows 7 libraries. Would Windows 7 libraries be another alternative to achieve this? All this reading to decide how to organize the partition scheme for my custom system is starting to be confusing. I apologize for this lengthy Question. It is my first day here on SuperUser and I am just learning how different from a discussion thread it is. Thank you in advance for all your suggestions and comments. Donat

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• Domain Models (PHP)

  - by Calum Bulmer

  I have been programming in PHP for several years and have, in the past, adopted methods of my own to handle data within my applications. I have built my own MVC, in the past, and have a reasonable understanding of OOP within php but I know my implementation needs some serious work. In the past I have used an is-a relationship between a model and a database table. I now know after doing some research that this is not really the best way forward. As far as I understand it I should create models that don't really care about the underlying database (or whatever storage mechanism is to be used) but only care about their actions and their data. From this I have established that I can create models of lets say for example a Person an this person object could have some Children (human children) that are also Person objects held in an array (with addPerson and removePerson methods, accepting a Person object). I could then create a PersonMapper that I could use to get a Person with a specific 'id', or to save a Person. This could then lookup the relationship data in a lookup table and create the associated child objects for the Person that has been requested (if there are any) and likewise save the data in the lookup table on the save command. This is now pushing the limits to my knowledge..... What if I wanted to model a building with different levels and different rooms within those levels? What if I wanted to place some items in those rooms? Would I create a class for building, level, room and item with the following structure. building can have 1 or many level objects held in an array level can have 1 or many room objects held in an array room can have 1 or many item objects held in an array and mappers for each class with higher level mappers using the child mappers to populate the arrays (either on request of the top level object or lazy load on request) This seems to tightly couple the different objects albeit in one direction (ie. a floor does not need to be in a building but a building can have levels) Is this the correct way to go about things? Within the view I am wanting to show a building with an option to select a level and then show the level with an option to select a room etc.. but I may also want to show a tree like structure of items in the building and what level and room they are in. I hope this makes sense. I am just struggling with the concept of nesting objects within each other when the general concept of oop seems to be to separate things. If someone can help it would be really useful. Many thanks

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• Stop YouTube Videos from Automatically Playing in Chrome

  - by The Geek

  If you’ve actually used the internet before, you’ve probably come across a page with an auto-playing YouTube clip, and chances are good it was a rather annoying one. Here’s how to stop them from starting automatically in Chrome. We’ve already told you how to stop them from automatically playing if you’re a Firefox user (best answer: use Flashblock!), but now it’s time for Chrome users to get their turn. Use the Stop Autoplay for YouTube Extension The great thing about this extension is that it stops the video from playing, but it allows it to continue buffering, so when you do feel like playing the video, it’ll already be downloaded—really useful for people with slower internet connections. There’s no UI or anything fancy, just head to the extension page and click the Install button. If you want to get rid of it later, use the Tools –> Extensions menu (or you can type chrome://extensions/ into your address bar), and then click the Uninstall link for that add-on.   Download Stop Autoplay for YouTube [Google Chrome Extensions] Using FlashBlock for Chrome If you really wanted to, you could just disable Flash across the board using FlashBlock for Chrome. Once you’ve installed the extension, you won’t see any Flash elements anywhere, and you’ll have to move your mouse over them and click to enable them each time. When I installed the extension the first time, I noticed that YouTube was already in the allow list. I’m not sure if that’s the default setting or not, but you can use the icon in the address bar, or the Options from the Extensions panel to get to the settings page, and from there you can remove anything from the White List that you wouldn’t want. Another nice feature about Flash Block is that it can also block Silverlight, or you could simply uninstall or remove unnecessary Chrome plug-ins. Download FlashBlock for Chrome Similar Articles Productive Geek Tips Stop YouTube Videos from Automatically Playing in FirefoxDisable YouTube Comments while using ChromeApologies About An Awful Audio AdvertisementImprove YouTube Video Viewing in Google ChromeWatch YouTube Videos in Cinema Style in Firefox TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Follow Finder Finds You Twitter Users To Follow Combine MP3 Files Easily QuicklyCode Provides Cheatsheets & Other Programming Stuff Download Free MP3s from Amazon Awe inspiring, inter-galactic theme (Win 7) Case Study – How to Optimize Popular Wordpress Sites

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• MapRedux - PowerShell and Big Data

  - by Dittenhafer Solutions

  MapRedux – #PowerShell and #Big Data Have you been hearing about “big data”, “map reduce” and other large scale computing terms over the past couple of years and been curious to dig into more detail? Have you read some of the Apache Hadoop online documentation and unfortunately concluded that it wasn't feasible to setup a “test” hadoop environment on your machine? More recently, I have read about some of Microsoft’s work to enable Hadoop on the Azure cloud. Being a "Microsoft"-leaning technologist, I am more inclinded to be successful with experimentation when on the Windows platform. Of course, it is not that I am "religious" about one set of technologies other another, but rather more experienced. Anyway, within the past couple of weeks I have been thinking about PowerShell a bit more as the 2012 PowerShell Scripting Games approach and it occured to me that PowerShell's support for Windows Remote Management (WinRM), and some other inherent features of PowerShell might lend themselves particularly well to a simple implementation of the MapReduce framework. I fired up my PowerShell ISE and started writing just to see where it would take me. Quite simply, the ScriptBlock feature combined with the ability of Invoke-Command to create remote jobs on networked servers provides much of the plumbing of a distributed computing environment. There are some limiting factors of course. Microsoft provided some default settings which prevent PowerShell from taking over a network without administrative approval first. But even with just one adjustment, a given Windows-based machine can become a node in a MapReduce-style distributed computing environment. Ok, so enough introduction. Let's talk about the code. First, any machine that will participate as a remote "node" will need WinRM enabled for remote access, as shown below. This is not exactly practical for hundreds of intended nodes, but for one (or five) machines in a test environment it does just fine. C:> winrm quickconfig WinRM is not set up to receive requests on this machine. The following changes must be made: Set the WinRM service type to auto start. Start the WinRM service. Make these changes [y/n]? y Alternatively, you could take the approach described in the Remotely enable PSRemoting post from the TechNet forum and use PowerShell to create remote scheduled tasks that will call Enable-PSRemoting on each intended node. Invoke-MapRedux Moving on, now that you have one or more remote "nodes" enabled, you can consider the actual Map and Reduce algorithms. Consider the following snippet: $MyMrResults = Invoke-MapRedux -MapReduceItem $Mr -ComputerName $MyNodes -DataSet $dataset -Verbose Invoke-MapRedux takes an instance of a MapReduceItem which references the Map and Reduce scriptblocks, an array of computer names which are the remote nodes, and the initial data set to be processed. As simple as that, you can start working with concepts of big data and the MapReduce paradigm. Now, how did we get there? I have published the initial version of my PsMapRedux PowerShell Module on GitHub. The PsMapRedux module provides the Invoke-MapRedux function described above. Feel free to browse the underlying code and even contribute to the project! In a later post, I plan to show some of the inner workings of the module, but for now let's move on to how the Map and Reduce functions are defined. Map Both the Map and Reduce functions need to follow a prescribed prototype. The prototype for a Map function in the MapRedux module is as follows. A simple scriptblock that takes one PsObject parameter and returns a hashtable. It is important to note that the PsObject $dataset parameter is a MapRedux custom object that has a "Data" property which offers an array of data to be processed by the Map function. $aMap = { Param ( [PsObject] $dataset ) # Indicate the job is running on the remote node. Write-Host ($env:computername + "::Map"); # The hashtable to return $list = @{}; # ... Perform the mapping work and prepare the $list hashtable result with your custom PSObject... # ... The $dataset has a single 'Data' property which contains an array of data rows # which is a subset of the originally submitted data set. # Return the hashtable (Key, PSObject) Write-Output $list; } Reduce Likewise, with the Reduce function a simple prototype must be followed which takes a $key and a result $dataset from the MapRedux's partitioning function (which joins the Map results by key). Again, the $dataset is a MapRedux custom object that has a "Data" property as described in the Map section. $aReduce = { Param ( [object] $key, [PSObject] $dataset ) Write-Host ($env:computername + "::Reduce - Count: " + $dataset.Data.Count) # The hashtable to return $redux = @{}; # Return Write-Output $redux; } All Together Now When everything is put together in a short example script, you implement your Map and Reduce functions, query for some starting data, build the MapReduxItem via New-MapReduxItem and call Invoke-MapRedux to get the process started: # Import the MapRedux and SQL Server providers Import-Module "MapRedux" Import-Module “sqlps” -DisableNameChecking # Query the database for a dataset Set-Location SQLSERVER:\sql\dbserver1\default\databases\myDb $query = "SELECT MyKey, Date, Value1 FROM BigData ORDER BY MyKey"; Write-Host "Query: $query" $dataset = Invoke-SqlCmd -query $query # Build the Map function $MyMap = { Param ( [PsObject] $dataset ) Write-Host ($env:computername + "::Map"); $list = @{}; foreach($row in $dataset.Data) { # Write-Host ("Key: " + $row.MyKey.ToString()); if($list.ContainsKey($row.MyKey) -eq $true) { $s = $list.Item($row.MyKey); $s.Sum += $row.Value1; $s.Count++; } else { $s = New-Object PSObject; $s | Add-Member -Type NoteProperty -Name MyKey -Value $row.MyKey; $s | Add-Member -type NoteProperty -Name Sum -Value $row.Value1; $list.Add($row.MyKey, $s); } } Write-Output $list; } $MyReduce = { Param ( [object] $key, [PSObject] $dataset ) Write-Host ($env:computername + "::Reduce - Count: " + $dataset.Data.Count) $redux = @{}; $count = 0; foreach($s in $dataset.Data) { $sum += $s.Sum; $count += 1; } # Reduce $redux.Add($s.MyKey, $sum / $count); # Return Write-Output $redux; } # Create the item data $Mr = New-MapReduxItem "My Test MapReduce Job" $MyMap $MyReduce # Array of processing nodes... $MyNodes = ("node1", "node2", "node3", "node4", "localhost") # Run the Map Reduce routine... $MyMrResults = Invoke-MapRedux -MapReduceItem $Mr -ComputerName $MyNodes -DataSet $dataset -Verbose # Show the results Set-Location C:\ $MyMrResults | Out-GridView Conclusion I hope you have seen through this article that PowerShell has a significant infrastructure available for distributed computing. While it does take some code to expose a MapReduce-style framework, much of the work is already done and PowerShell could prove to be the the easiest platform to develop and run big data jobs in your corporate data center, potentially in the Azure cloud, or certainly as an academic excerise at home or school. Follow me on Twitter to stay up to date on the continuing progress of my Powershell MapRedux module, and thanks for reading! Daniel

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• Strange rendering in XNA/Monogame

  - by Gerhman

  I am trying to render G-Code generated for a 3d-printer as the printed product by reading the file as line segments and the drawing cylinders with the diameter of the filament around the segment. I think I have managed to do this part right because the vertex I am sending to the graphics device appear to have been processed correctly. My problem I think lies somewhere in the rendering. What basically happens is that when I start rotating my model in the X or Y axis then it renders perfectly for half of the rotation but then for the other half it has this weird effect where you start seeing through the outer filament into some of the shapes inside. This effect is the strongest with X rotations though. Here is a picture of the part of the rotation that looks correct: And here is one that looks horrible: I am still quite new to XNA and/Monogame and 3d programming as a whole. I have no idea what could possibly be causing this and even less of an idea of what this type of behavior is called. I am guessing this has something to do with rendering so have added the code for that part: protected override void Draw(GameTime gameTime) { GraphicsDevice.Clear(Color.Black); basicEffect.World = world; basicEffect.View = view; basicEffect.Projection = projection; basicEffect.VertexColorEnabled = true; basicEffect.EnableDefaultLighting(); GraphicsDevice.SetVertexBuffer(vertexBuffer); RasterizerState rasterizerState = new RasterizerState(); rasterizerState.CullMode = CullMode.CullClockwiseFace; rasterizerState.ScissorTestEnable = true; GraphicsDevice.RasterizerState = rasterizerState; foreach (EffectPass pass in basicEffect.CurrentTechnique.Passes) { pass.Apply(); GraphicsDevice.DrawPrimitives(PrimitiveType.TriangleList, 0, vertexBuffer.VertexCount); } base.Draw(gameTime); } I don't know if it could be because I am shading something that does not really have a texture. I am using this custom vertex declaration I found on some tutorial that allows me to store a vertex with a position, color and normal: public struct VertexPositionColorNormal { public Vector3 Position; public Color Color; public Vector3 Normal; public readonly static VertexDeclaration VertexDeclaration = new VertexDeclaration ( new VertexElement(0, VertexElementFormat.Vector3, VertexElementUsage.Position, 0), new VertexElement(sizeof(float) * 3, VertexElementFormat.Color, VertexElementUsage.Color, 0), new VertexElement(sizeof(float) * 3 + 4, VertexElementFormat.Vector3, VertexElementUsage.Normal, 0) ); } If any of you have ever seen this type of thing please help. Also, if you think that the problem might lay somewhere else in my code then please just request what part you would like to see in the comments section.

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• What can a Service do on Windows?

  - by Akemi Iwaya

  If you open up Task Manager or Process Explorer on your system, you will see many services running. But how much of an impact can a service have on your system, especially if it is ‘corrupted’ by malware? Today’s SuperUser Q&A post has the answers to a curious reader’s questions. Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites. The Question SuperUser reader Forivin wants to know how much impact a service can have on a Windows system, especially if it is ‘corrupted’ by malware: What kind malware/spyware could someone put into a service that does not have its own process on Windows? I mean services that use svchost.exe for example, like this: Could a service spy on my keyboard input? Take screenshots? Send and/or receive data over the internet? Infect other processes or files? Delete files? Kill processes? How much impact could a service have on a Windows installation? Are there any limits to what a malware ‘corrupted’ service could do? The Answer SuperUser contributor Keltari has the answer for us: What is a service? A service is an application, no more, no less. The advantage is that a service can run without a user session. This allows things like databases, backups, the ability to login, etc. to run when needed and without a user logged in. What is svchost? According to Microsoft: “svchost.exe is a generic host process name for services that run from dynamic-link libraries”. Could we have that in English please? Some time ago, Microsoft started moving all of the functionality from internal Windows services into .dll files instead of .exe files. From a programming perspective, this makes more sense for reusability…but the problem is that you can not launch a .dll file directly from Windows, it has to be loaded up from a running executable (exe). Thus the svchost.exe process was born. So, essentially a service which uses svchost is just calling a .dll and can do pretty much anything with the right credentials and/or permissions. If I remember correctly, there are viruses and other malware that do hide behind the svchost process, or name the executable svchost.exe to avoid detection. Have something to add to the explanation? Sound off in the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.

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• How do software projects go over budget and under-deliver?

  - by Carlos

  I've come across this story quite a few times here in the UK: NHS Computer System Summary: We're spunking £12 Billion on some health software with barely anything working. I was sitting the office discussing this with my colleagues, and we had a little think about. From what I can see, all the NHS needs is a database + middle tier of drugs/hospitals/patients/prescriptions objects, and various GUIs for doctors and nurses to look at. You'd also need to think about security and scalability. And you'd need to sit around a hospital/pharmacy/GPs office for a bit to figure out what they need. But, all told, I'd say I could knock together something with that kind of structure in a couple of days, and maybe throw in a month or two to make it work in scale. * If I had a few million quid, I could probably hire some really excellent designers to make a maintainable codebase, and also buy appropriate hardware to run the system on. I hate to trivialize something that seems to have caused to much trouble, but to me it looks like just a big distributed CRUD + UI system. So how on earth did this project bloat to £12B without producing much useful software? As I don't think the software sounds so complicated, I can only imagine that something about how it was organised caused this mess. Is it outsourcing that's the problem? Is it not getting the software designers to understand the medical business that caused it? What are your experiences with projects gone over budget, under delivered? What are best practices for large projects? Have you ever worked on such a project? EDIT *This bit seemed to get a lot of attention. What I mean is I could probably do this for say, 30 users, spending a few tens of thousands of pounds. I'm not including stuff I don't know about the medical industry and government, but I think most people who've been around programming are familiar with that kind of database/front end kind of design. My point is the NHS project looks like a BIG version of this, with bells and whistles, notably security. But surely a budget millions of times larger than mine could provide this?

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• Evaluating Scrum - is it okay to have people with multiple roles in a Scrum team?

  - by Wayne M

  I'm evaluating some Agile-style methodologies for possible introduction to my team. With Scrum, is it allowable to have the same person perform multiple roles? We have a small team of four developers and a web designer; we don't really have a lead (I fulfill this role), QA testers or business analysts, and all of our development tasks come from the CIO. Automated testing is seen as a total waste of time, and everything focuses on speed and not quality. What will happen is the CIO will come up with a development task (whether a feature or a bug) and give it to a developer (not to the whole team, to an individual, often in private or out of the blue) who is then expected to get it completed. The CIO doesn't gather requirements beyond the initial idea (and this has bitten us before as we'll implement something only to find out that none of the end users can use the feature, because they weren't consulted or even informed about it before we developed it, and in a panic we'll be told to revert the change) but requires say in/approval of everything that we do. First things first, is a Scrum style something to consider to introduce some standards and practices? From reading, Scrum seems to rely on a bit more trust and communication and focuses more on project management than on development, which is something we are completely devoid of as we don't have any semblance of project management at present. Second, if it can work is it unreasonable for someone, let's say myself, to act as both ScrumMaster and a developer? Or for a developer to also be the Product Owner (although chances are this will be the CIO, who isn't a developer)? I realize the Scrum Master and the Product Owner should be different people but at the same time I don't think we have anyone who has the qualities of a Product Owner (chances are it would turn into a "I need all these stories, I don't care how but get it done" type of deal and/or any freeze would be unfrozen on a whim). It seems to me that I might need to pick and choose pieces of Scrum/XP/Lean to compensate for how things are done currently, as it's highly unlikely that the mentality can be changed; for instance Pair Programming would never fly (seen as a waste, you get half the tasks done if you need two people for everything), TDD would be a hard sell, but short cycles would be welcomed.

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• Is there any good hosting for asp.net and MySQL

  - by HAJJAJ

  HI every one ,I have account with one of the hosting company, and i did my project in asp.net and I used MySQL for the database. the hosting company is not giving me the full privileges to create new user or to create new stored procedure!!! this is what they said for me: Due to the shared nature of our environment we had to make some modifications to your procedure (namely the definer). We also had to review your procedure to determine if it would be compatible with our environment. While your procedures will work (via phpMyAdmin or some other interface), it is unlikely they will be accessible via the Connector/.NET (ADO.NET) that your application is likely using. This is due to a security restriction with how that connector works in shared environments. http://dev.mysql.com/doc/refman/5.0/en/connector-net-programming-stored.html "Note When you call a stored procedure, the command object makes an additional SELECT call to determine the parameters of the stored procedure. You must ensure that the user calling the procedure has the SELECT privilege on the mysql.proc table to enable them to verify the parameters. Failure to do this will result in an error when calling the procedure." Unfortunately, giving read privileges on the mysql.proc table will give you access to the data of our other customers and that is not an acceptable risk. If your application can only work using stored procedures, then MSSQL will probably be the better option for your site. I apologize for the inconvenience and the wait to have this ticket completed. So is there any good hosting that any body already used it to publish his asp.net and mysql project ??? this is one of my stored procedure and i think it's sample and it will not harm any other uses!!: -- -------------------------------------------------------------------------------- -- Routine DDL -- Note: comments before and after the routine body will not be stored by the server -- -------------------------------------------------------------------------------- DELIMITER $$ CREATE DEFINER=`root`@`localhost` PROCEDURE `SpcategoriesRead`( IN PaRactioncode VARCHAR(5), IN PaRCatID BIGINT, IN PaRSearchText TEXT ) BEGIN -- CREATING TEMPORARY TABLE TO SAVE DATA FROM THE ACTIONCODE SELECTS -- DROP TEMPORARY TABLE IF EXISTS TEMP; CREATE temporary table tmp ( CatID BIGINT primary key not null, CatTitle TEXT, CatDescription TEXT, CatTitleAr TEXT, CatDescriptionAr TEXT, PictureID BIGINT, Published BOOLEAN, DisplayOrder BIGINT, CreatedOn DATE ); IF PaRactioncode = 1 THEN -- Retrive all DATA from the database -- INSERT INTO tmp SELECT CatID,CatTitle,CatDescription,CatTitleAr,CatDescriptionAr,PictureID,Published,DisplayOrder,CreatedOn FROM tbcategories; ELSEIF PaRactioncode = 2 THEN -- Retrive all from the database By ID -- INSERT INTO tmp SELECT CatID,CatTitle,CatDescription,CatTitleAr,CatDescriptionAr,PictureID,Published,DisplayOrder,CreatedOn FROM tbcategories WHERE CatID=PaRCatID; ELSEIF PaRactioncode = 3 THEN -- NOSET YET -- INSERT INTO tmp SELECT CatID,CatTitle,CatDescription,CatTitleAr,CatDescriptionAr,PictureID,Published,DisplayOrder,CreatedOn FROM tbcategories WHERE Published=1 ORDER BY DisplayOrder; END IF; IF PaRSearchText IS NOT NULL THEN set PaRSearchText=concat('%', PaRSearchText ,'%'); SELECT CatID,CatTitle,CatDescription,CatTitleAr,CatDescriptionAr,PictureID,Published,DisplayOrder,CreatedOn FROM tmp WHERE Concat(CatTitle, CatDescription, CatTitleAr, CatDescriptionAr) LIKE PaRSearchText; ELSE SELECT CatID,CatTitle,CatDescription,CatTitleAr,CatDescriptionAr,PictureID,Published,DisplayOrder,CreatedOn FROM tmp; END IF; DROP TEMPORARY TABLE IF EXISTS tmp; END

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• How do I import my first sprites?

  - by steven_desu

  Continuing from this question (new question - now unrelated) So I have a thorough background in programming already (algorithms, math, logic, graphing problems, etc.) however I've never attempted to code a game before. In fact, I've never had anything more than minimal input from a user during the execution of a program. Generally input was given from a file or passed through console, all necessary functions were performed, then the program terminated with an output. I decided to try and get in on the world of game development. From several posts I've seen around gamedev.stackexchange.com XNA seems to be a favorite, and it was recommended to me when I asked where to start. I've downloaded and installed Visual Studio 2010 along with the XNA Framework and now I can't seem to get moving in the right direction. I started out looking on Google for "xna game studio tutorial", "xna game development beginners", "my first xna game", etc. I found lots of crap. The official "Introduction to Game Studio 4.0" gave me this (plus my own train of thought happily pasted on top thanks to MSPaint): http://tinypic.com/r/2w1sgvq/7 The "Get Additional Help" link (my best guess, since there was no "Continue" or "Next" link) lead me to this page: http://tinypic.com/r/2qa0dgx/7 I tried every page. The forum was the only thing that seemed helpful, however searching for "beginner", "newbie", "getting started", "first project", and similar on the forums turned up many threads with specific questions that are a bit above my level ("beginner to collision detection", for instance) Disappointed I returned to the XNA Game Studio home page. Surely their own website would have some introduction, tutorial, or at least a useful link to a community. EVERYTHING on their website was about coding Windows Phone 7.... Everything. http://tinypic.com/r/10eit8i/7 http://tinypic.com/r/120m9gl/7 Giving up on any official documentation after a while, I went back to Google. I managed to locate www.xnadevelopment.com. The website is built around XNA Game Studio 3.0, but how different can 3.0 be from 4.0?.... Apparently different enough. http://tinypic.com/r/5d8mk9/7 http://tinypic.com/r/25hflli/7 Figuring that this was the correct folder, I right-clicked.... http://tinypic.com/r/24o94yu/7 Hmm... maybe by "Add Content Reference" they mean "Add a reference to an existing file (content)"? Let's try it (after all- it's my only option) http://tinypic.com/r/2417eqt/7 At this point I gave up. I'm back. My original goal in my last question was to create a keyboard-navigable 3D world (no physics necessary, no logic or real game necessary). After my recent failures my goal has been revised. I want to display an image on the screen. Hopefully in time I'll be able to move it with the keyboard.

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• Introducing Agile development after traditional project inception

  - by Riggy

  About a year and a half ago, I entered a workplace that claimed to do Agile development. What I learned was that this place has adopted several agile practices (such as daily standups, sprint plannings and sprint reviews) but none of the principles (just in time / just good enough mentality, exposing failure early, rich communication). I've now been tasked with making the team more agile and I've been assured that I have complete buy-in from the devs and the business team. As a pilot program, they've given me a project that just completed 15 months of requirements gathering, has a 110 page Analysis & Design document (to be considered as "written in stone"), and where I have no access to the end users (only to the committee made up of the users' managers who won't actually be using the product). I started small, giving them a list of expected deliverables for the first 5 sprints (leaving the future sprints undefined), a list of goals for the first sprint, and I dissected the A&D doc to get enough user stories to meet the first sprint's goals. Since then, they've asked why we don't have all the requirements for all the sprints, why I haven't started working on stuff for the third sprint (which they consider more important but is based off of the deliverables of the first 2 sprints) and are pressing for even more documentation that my entire IT team considers busy-work or un-related to us (such as writing the user manual up-front, documenting all the data fields from all the sprints up front, and more "up-front" work). This has been pretty rough for me as a new project manager, but there are improvements I have effectively implemented such as scrumban for story management, pair programming, and having the business give us customer acceptance tests up front (as part of the requirements documentation). So my questions are: What can I do to more effectively introduce change to a resistant business? Are there other practices that I can introduce on the IT side to help show the business the benefits of agile? The burden of documentation is strangling us - the business still sees it as a risk management strategy instead of as a risk. What can we do to alleviate their documentation concerns and demands (specifically the quantity of documentation and their need for all of it up front)? We are in a separate building from our business, about 3 blocks away and they refuse to have their people on the project co-habitate b/c that person "won't be able to work on their other projects while they're at our building." They expect us to always go over there and to bundle our questions so that we can ask them all at once and not waste that person's time with "constant interruptions." What can we do to get richer communication from them? Any additional advice would also be appreciated. Thanks!

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• DBA Best Practices - A Blog Series: Episode 1 - Backups

  - by Argenis

    This blog post is part of the DBA Best Practices series, on which various topics of concern for daily database operations are discussed. Your feedback and comments are very much welcome, so please drop by the comments section and be sure to leave your thoughts on the subject. Morning Coffee When I was a DBA, the first thing I did when I sat down at my desk at work was checking that all backups had completed successfully. It really was more of a ritual, since I had a dual system in place to check for backup completion: 1) the scheduled agent jobs to back up the databases were set to alert the NOC in failure, and 2) I had a script run from a central server every so often to check for any backup failures. Why the redundancy, you might ask. Well, for one I was once bitten by the fact that database mail doesn't work 100% of the time. Potential causes for failure include issues on the SMTP box that relays your server email, firewall problems, DNS issues, etc. And so to be sure that my backups completed fine, I needed to rely on a mechanism other than having the servers do the taking - I needed to interrogate the servers and ask each one if an issue had occurred. This is why I had a script run every so often. Some of you might have monitoring tools in place like Microsoft System Center Operations Manager (SCOM) or similar 3rd party products that would track all these things for you. But at that moment, we had no resort but to write our own Powershell scripts to do it. Now it goes without saying that if you don't have backups in place, you might as well find another career. Your most sacred job as a DBA is to protect the data from a disaster, and only properly safeguarded backups can offer you peace of mind here. "But, we have a cluster...we don't need backups" Sadly I've heard this line more than I would have liked to. You need to understand that a cluster is comprised of shared storage, and that is precisely your single point of failure. A cluster will protect you from an issue at the Operating System level, and also under an outage of any SQL-related service or dependent devices. But it will most definitely NOT protect you against corruption, nor will it protect you against somebody deleting data from a table - accidentally or otherwise. Backup, fine. How often do I take a backup? The answer to this is something you will hear frequently when working with databases: it depends. What does it depend on? For one, you need to understand how much data your business is willing to lose. This is what's called Recovery Point Objective, or RPO. If you don't know how much data your business is willing to lose, you need to have an honest and realistic conversation about data loss expectations with your customers, internal or external. From my experience, their first answer to the question "how much data loss can you withstand?" will be "zero". In that case, you will need to explain how zero data loss is very difficult and very costly to achieve, even in today's computing environments. Do you want to go ahead and take full backups of all your databases every hour, or even every day? Probably not, because of the impact that taking a full backup can have on a system. That's what differential and transaction log backups are for. Have I answered the question of how often to take a backup? No, and I did that on purpose. You need to think about how much time you have to recover from any event that requires you to restore your databases. This is what's called Recovery Time Objective. Again, if you go ask your customer how long of an outage they can withstand, at first you will get a completely unrealistic number - and that will be your starting point for discussing a solution that is cost effective. The point that I'm trying to get across is that you need to have a plan. This plan needs to be practiced, and tested. Like a football playbook, you need to rehearse the moves you'll perform when the time comes. How often is up to you, and the objective is that you feel better about yourself and the steps you need to follow when emergency strikes. A backup is nothing more than an untested restore Backups are files. Files are prone to corruption. Put those two together and realize how you feel about those backups sitting on that network drive. When was the last time you restored any of those? Restoring your backups on another box - that, by the way, doesn't have to match the specs of your production server - will give you two things: 1) peace of mind, because now you know that your backups are good and 2) a place to offload your consistency checks with DBCC CHECKDB or any of the other DBCC commands like CHECKTABLE or CHECKCATALOG. This is a great strategy for VLDBs that cannot withstand the additional load created by the consistency checks. If you choose to offload your consistency checks to another server though, be sure to run DBCC CHECKDB WITH PHYSICALONLY on the production server, and if you're using SQL Server 2008 R2 SP1 CU4 and above, be sure to enable traceflags 2562 and/or 2549, which will speed up the PHYSICALONLY checks further - you can read more about this enhancement here. Back to the "How Often" question for a second. If you have the disk, and the network latency, and the system resources to do so, why not backup the transaction log often? As in, every 5 minutes, or even less than that? There's not much downside to doing it, as you will have to clear the log with a backup sooner than later, lest you risk running out space on your tlog, or even your drive. The one drawback to this approach is that you will have more files to deal with at restore time, and processing each file will add a bit of extra time to the entire process. But it might be worth that time knowing that you minimized the amount of data lost. Again, test your plan to make sure that it matches your particular needs. Where to back up to? Network share? Locally? SAN volume? This is another topic where everybody has a favorite choice. So, I'll stick to mentioning what I like to do and what I consider to be the best practice in this regard. I like to backup to a SAN volume, i.e., a drive that actually lives in the SAN, and can be easily attached to another server in a pinch, saving you valuable time - you wouldn't need to restore files on the network (slow) or pull out drives out a dead server (been there, done that, it’s also slow!). The key is to have a copy of those backup files made quickly, and, if at all possible, to a remote target on a different datacenter - or even the cloud. There are plenty of solutions out there that can help you put such a solution together. That right there is the first step towards a practical Disaster Recovery plan. But there's much more to DR, and that's material for a different blog post in this series.

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• How to keep balance / Unlock items / achievement rules

  - by Mark Knol

  I'm working on an engine for a game, too learn javascript and just because its fun. I'm a flashdeveloper, I know how to build websites. Now making games is a different challenge, javascript is a challenge, but I'd love to learn how to structure code and what patterns are common. I dont mind if the game ever finish, I'm mostly interested in the programming part of it. I dont have a particular endresult in mind, so I'll see where it takes me. I currently have a system where you can buy items. The items cost a specified amount of gold, silver, diamonds etc. When you have selected and bought the item, it takes time before getting rewarded. When time is over, you are getting rewarded with other properties (gold, energy, diamonds). For example, you can buy an apple for 50gold, It takes a minute, you get rewarded with 75energy. Or if you take a run, it cost 50energy, it takes 5minutes, reward is 25gold and 25silver. These definitions is what i call actions. Currently I already have a system where this already works and I can define as much actions with as much properties as I want. The definitions I have kinda looks like this: {id:101, category:544, onInit:{gold:-75}, onComplete:{energy:75}, time:2000, name:"Apple", locked: false} {id:102, category:544, onInit:{gold:-135}, onComplete:{energy:145}, time:2000, name:"Banana", locked: false} {id:106, category:302, onInit:{energy:-50, power: -25}, onComplete:{gold:100, diamonds:2}, time:10000, name:"Run", locked: false} {id:107, category:302, onInit:{energy:-70, silver: -55}, onComplete:{gold:100}, time:10000, name:"Dance", locked: false} {id:108, category:302, onInit:{energy:-230, power: -355}, onComplete:{gold:70, silver:70}, time:10000, name:"Fitness", locked: false} Now, I would love to add a system where I can lock/unlock the actions using achievement rules. Lets say, if you buy 10 apples, you unlock a new action, like bananas which cost more, and reward more. In the future I maybe want to restrict achievements and actions to levels. I am kinda stuck how to structure this. I have 2 questions: Which patterns are used to define achievements? How/where are they defined? Should it be part of the action, or should it be a separate controller? Is it a good idea to register all completed actions to it? I think I want multiple types of achievement rules, Id love to hear some ideas how to develop it. How do you create/find a good balance, so the user does not get stuck or can cheat by repeat a pattern of actions to get too much rewards. I know there is not a simple answer and i'm lacking of a good game-concept, but I wonder if anyone created such a game and how you dealed and played with it.

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• Moving from Tortoise to TFS

  - by MarkPearl

  The Past A few years ago my small software company made the jump from storing code on a shared folder to source code control. At the time we had evaluated a few of the options and settled on Tortoise SVN. The main motivation for going the SVN route was that we found a great plugin for Visual Studio that allowed us to avoid the command prompt for uploading changes (like I said we are windows programmers… command prompt bad!! ) and it was free. Up to now we have been pretty happy with SVN as it removed many of the worries that I had about how safe my code was on a shared folder and also gave us the opportunity to safely have several developers work on the same project at the same time. The only times when we have been unhappy has been when we have had SVN hell days – which pretty much occur when you are doing something out of the norm and suddenly SVN just won’t resolve conflicts or something along those lines. This happens once every 4 or 5 months and is not necessarily a problem caused directly by SVN – but a problem augmented by SVN. When you have SVN hell days you want to curse SVN! With that in mind I recently have been relooking at our source code control. I have explored using GIT and was very impressed by it and have also looked at TFS. From a source code control perspective I don’t want to get into a heated discussion on which one is better – but I do want to mention that I wear two hats in my organization – software developer & manager, and with the manager hat on I tend to sway the TFS route. So when I was given a coupon to test DiscountASP.Net Team Foundation Server Service for a year, I thought it was the perfect opportunity to try TFS in a distributed environment and also make the first step towards having an integrated development management system. Some of the things that appeal to me about DiscountASP’s offering are the following… Basic management / planning facilities like to do lists inside Visual Studio Daily backup of data on the server – we are developers, not IT managers and so the more of this I could outsource the better Distributed solution – all of us work remotely and so this was a big one as well. Registering and Setting Up with DiscountASP.NET The whole registration process was simple and intuitive. The web interface is not the most visually impressive one, but it is functional and a few seconds after I clicked the last submit button a email was sitting in my inbox giving me my control panel username and suggesting that I read the “Getting Started” article. The getting started article was easy to read and understand so no complaints there either. Next to set my dev environment to work. With a few references to the getting started article I had completed the whole setup process in a matter of minutes. Ten minutes after initiating the whole thing I was logged into VS2010 and creating my first TFS project. With the service that I signed up for, I have access for 5 users – which is sufficient for my internal needs. So from what I can tell, to set the rest of us up on the system I just need to supply them with their user credentials and url. My Concerns Resolved 1) Security So, a few concerns I had about the service. First and foremost – is it secure? I would hate for someone to get access to our code and the whole idea of putting it up on the internet is a concern for me. Turning to the Knowledge Base on the DiscountASP website this is one of the first question I can see answered. According to them it is secure. I have extracted their comment below regarding this. Our TFS hosting service is secure. We only accept HTTPS connections ensuring that any client-server data transmission is encrypted. At the network level, all of our systems are protected by multiple Juniper firewalls, Tipping Point's Intrusion Detection System (see Tipping Point's case study of our use here), and we also employ DDoS mitigation to add extra layers of security. Additionally, physical access to the servers is tightly restricted. Please see the security section of this Knowledge Base article for further details. 2) Web Portal Access The other big concern I have is regarding web portal access. In the ideal world I would like to be able to give my end users access to a web portal for reporting bugs etc. When I initially read through the FAQ of the site it mentioned that there was web portal access – but from what I can see this is just for “users”. Since I am limited to 5 users for the account, it would not be practical to set up external users that we could get feedback from on bugs etc. I would be interested if this is possible – and if so if someone could post it in the comments it would be much appreciated. If this isn’t possible, it is a slight let down as we rely heavily on end user feedback to get feedback and it would have been ideal to have gotten this within the service. Other than those two items, I didn’t have any real concerns that were unresolved. So where do I go from here? So time passed by from the initial writing of this post and as work whirred in and out of my inbox I have still not had a proper opportunity to give the service a test run. Recently though things have began to slow down and then surprise surprise I had another SVN Hell day. With that experience I had a new found resolve to get our team on TFS and so today we are going to start to use the service as a team. I am hoping that I do not have TFS hell days – but if I do, I will be sure to write about them. In short - the verdict is still out on whether this service is going to be invaluable to my business or whether it will create more headaches than it is worth BUT I am hopping it will be an invaluable service. I will only really be able to determine that in a few months… till then!

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• Need personal advice on how to get out of a company..

  - by SOfan

  Hi, I am an SO user since past 6 months and this is the first time I am turning to SO for personal help. I have asked technical questions before with my real ID. I am stuck inside a service based IT company for the past one year and haven't been able to decide if to leave it, when to leave it and how to leave it. I had taken 2 weeks LWP on medical reason roughly at end of 1 year and then soon after reporting, I applied for 2 months more LWP (on medical/personal ground) with the intention of working on my health,take up a hobby class to ward off depression,pessimism, to have some fun in life, and to look for a job which I really would be excited about - that interests me and which matches with my strength. My leave starts from this Monday. So in any case, I had hard set in mind that I will leave the company after I join them back hopefully with some job offer already in hand (after figuring out what I want do). Neither I can stand the past project,past colleagues,company, HR, pathetically low salary. But if I really listen to my heart, I don't want to have to go back to that office after my sabbatical and again have to see those people. I will have to resign it after my sabbatical ends. Then HR people perhaps wont like it, may even accuse me on face or behind back that primary purpose of my leave must have been to hunt for a better job and I lied about medical and person reasons. Also, if they get nasty and force me to serve 2 months notice period. There is no way I see myself after sabbatical resuming in old project or starting new work. It will be a pain. Since they have already approved 2 months leave and stuff, ideally if they want, they should be just able to relieve me right on the next day after I join back. But, I don't know if they want to get nasty, will they mention about my 2 months sabbatical leave in my experience letter or more scary, the term medical/personal reason. I have hard earned my experience here, have worked against my will, mostly it has been painful and slogged like anything, because I realize the importance of work experience in IT industry. I don't have greed to have those 2 months included extra in my experience letter, but I don't want to mess up with my experience letter in a way which makes my next employer ask question, get suspicious, or be wary if I have any medical reason going on. Being an emotional,moody person or somebody who can't be in an environment, once my mind and heart starts hating it. I think it perhaps is best, if I resign on Monday itself telling them (in polite manner) something that look I took sabbatical for some reason but I don't want to resume working in the company after my sabbatical ends. So please accept my resignation. Now tell me what you want to do about my leave request, my notice period and when you are willing to relieve me. What should I write and how? Some background: I am working in an IT company in India.I am overqualified in the company. It is grossly underpaying me. My education qualifications far exceed anyone's in the whole company being a CS undergrad as well as a CS grad. I joined this company after finishing the grad. I had self-doubts about my skills and interest as a programmer. I like doing research oriented work, though didn't have any particular success during grad. My life here has been very hectic. The project containing many many sub-projects has kept me on my toes and I have never really liked the work. I have been playing against my strength. Also the company strict internet usage policy (you can't read gmails, can't browse any non-work related sites not even news). When working for a client, from the machine we can't even check company related emails.For this one has to go to kiosk like 5 machines in a small room etc. Most of the times those machines are not available, so it was not unusual to keep making rounds to these kiosk machines to check company emails, browse company related emails etc.So it was not so easy to keep in touch with company related basic affairs for a not particular careful person. Things like this which are new to me, make me feel restricted. I am an undecisive person with a sense of failure, self-doubt, not meeting up unrealistic expectation. Somewhere at back of mind, I envy my classmates who make a smooth transition from company to company without causing any gap in their resume. I on other hand have gaps in resume. I get tired after working in a place for sometime. problem with colleagues in general. I am not particular great with people, have few friends, not known for a fun nature, rather serious, scholar. I am not a typical conventional female. I think females are usually more disciplined. But I am not so. I reach office late (though after informing manager). I don't want to blame them entirely, because from my past, it is not unusual for me to get undecisive on things. Also I had doubts about my ability as researched and to succeed there. of building a relationship in a group, to have something to talk about, newspaper. I get cut-off from people. peer pressure. I make blunders in coding, lose patience. Consciously or unconsciously I feel contempt for people here, work here, environment here. I have doubts that either I go to a place which does innovation, does research oriented work, product biggies, have great motivated people, have competent people passionate about products they are building. But then I also doubt my ability to survive there. I have identified that an idea job for me would be 4 days a week, a high salary job. When among people in company/team, I can't think much. I need some time at home to read good authentic books written in good style on what work I am doing.So that I am comfortable with my understanding of work. I get into pressure easily under deadline and need 5th day to cool myself off. I took for 2 weeks leave, because each day was hell for me. May be the depression phase of bipolar is on and also partially it could be that being a work centered person, who derives happiness,self-esteem from work, haven't been enjoying work and have been working for the sole person of proving stability, and ability to stick, against all odds, and facing what challenges I see, bonding with people, identifying opportunities to learn in given task etc.have been averaging one day LWP in 1 week or 10 days. or may be because of my nature,ADD,not being able to switch context,out of touch with news, don't have a circle of friends with who I enjoy. less knowledge in general to talk about, just some technical stuff.anyway, so due to emotional reason, some practical reason etc, I wanted to be very sure before leaving. So my leave starts from Monday and I should feel happy about it. I have taken the leave to for a few purposes - to take care of my health by regular yoga/exercise (with project on, I just can't do anything regular), reassess myself to see what I want to try next which work I might like, look for next job, take up a hobby which I like say singing. I am not clear on my career,job aspiration. I have tried my hands on research. During this year appraisal yesterday, I even had some conflict with my last manager. In meeting with me one on one, he would say all nice things about me, but in feedback to new manager, he hasn't given any excellent feedback. It is all only good. I am angry at this old Manager. Also new manager also scolded me as I didn't agree to his appraisal and waited to hear myself from old Manager. He kind of scolded me for wasting his time. Am I being unethical somewhere? I am always very conscious of if I am cheating anywhere. What advice I am seeking? How to resign and what to write in resignation letter

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• Interconnect nodes in a Java distributed infrastructure for tweet processing

  - by David Moreno García

  I'm working in a new version of an old project that I used to download and process user statuses from Twitter. The main problem of that project was its infrastructure. I used multiple instances of a java application (trackers) to download from Twitter given an specific task (basically terms to search for), connected with a central node (a web application) that had to process all tweets once per day and generate a new task for each trackers once each 15 minutes. The central node also had to monitor all trackers and enable/disable them under user petition. This, as I said, was too slow because I had multiple bottlenecks, so in this new version I want to improve the infrastructure and isolate all functionalities in specific nodes. I also need a good notification system to receive notifications for any node. So, in the next diagram I show the components that I'll need in this new version: As you can see, there are more nodes. Here are some notes about them: Dashboard: Controls trackers statuses and send a single task to each of them (under user request). The trackers will use this task until replaced with a new one (if done, not each 15 minutes like before). Search engine: I need to store all the tweets. They are firstly stored in a local database for each tracker but after that I'm thinking on using something like Elasticsearch to be able to do fast searches. Tweet processor: Just and isolated component with its own database (maybe something like the search engine to have fast access to info generated by the module). In the future more could be added. Application UI: A web application with a shared database with the Dashboard (mainly to store users information and preferences). Indeed, both could be merged into a single web. The main difference with the previous version of the project is that now they will be isolated and they will only show information and send requests. I will not do any heavy task in them (like process tweets as I did before). So, having this components, my main headache is how to structure all to not have to rewrite a lot of code every time I need to access any new data. Another headache is how can I interconnect nodes. I could use sockets but that is a pain in the ass. Maybe a REST layer? And finally, if all the nodes are isolated, how could I generate notifications for each user which info is only in the database used by the Application UI? I'm programming this using Java and Spring (at least I used them in the last version) but I have no problems with changing the language if I can take advantage of a tool/library/engine to make my life easier and have a better platform. Any comment will be appreciated.

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• I Know What I Did This Summer: Put Down Trex Decking

  - by thatjeffsmith

  If you’re wondering why I would bore everyone with my pictures and frequent status updates/tweets from the past week – it’s so I could document the process of refurbishing my deck, or what some would call a porch. When we go to take a vacation, buy a car, do anything – we also read personal blogs to get the real story. So, if you’re curious about what it takes to tackle this sort of project, read on. Skills/Equipment/Manpower We Possessed I took the old decking out by myself. I’m about 230 lbs, more than 6′ tall, and I’m pretty healthy. This took about 8 hours over two afternoons. Three of us put the deck back together. My wife has two engineering degrees. Her father also has two engineering degrees. Lots of brainpower available here. Also, her dad ran the public works department for a country for more than 20 years – so lots and lots of practical experience on hand. We had a compound mitre saw, a skilsaw, 2-3 crowbars, a framing hammer, 3 cordless drills, a corded drill, lots of sawhorses, a power sander, an angle grinder, a 10×10 Coleman canopy tent, a Ford F-150 pickup truck, outdoor speakers and lots of iTunes playlists, plenty of water and cold beer. Why We Did This Our deck was relatively young – it was built in 2005. However, the pressure treated boards must not have been adequately maintained before we bought the house. I had powerwashed the deck every other year and had it stained a few times. The boards just rotted. We’re going to be in the house for a long time, and we wanted something that would look nice and require little maintenance. More bad deck boards The deck boards were in bad shape Things We Learned The two most important things: The hidden fasteners have to be put in JUST right. Wedge them into the grooved board, then bend down the bit that is screwed down. We didn’t do this on the first board and couldn’t get the second board to fit nearly close enough. Watching the official TREX YouTube video helped immensely, and we should have watched that first. When pre-drilling holes for the boards that need screwed down – DO NOT pre-drill through the underlying framing wood. ONLY pre-drill through the TREX itself. The screw won’t seat in the board properly. Instead of sitting down flush with the board, it will stop at the top of the board and just spin. I had to call the the place that sold me the screws to find this out. So about a third of our screws look like crap. If it doesn’t look or feel right – stop everything and pick up your computer or your phone. It’s not right, and it will be much easier to stop and find out why. We didn’t do this, and now I’m going to see every screw that’s not flush with the boards and get upset. Oh well. The Process How much time did it take? Well I spent about 8 hours taking the deck apart. And then the 3 of use spent 8 hours the first day, 10 hours the second day, 8 hours the third, and another 6 hours on the fourth day. That’s like 104 man-hours. We supposedly saved four or five thousand dollars in labor, but don’t do the math here or you might get a bit upset. The main thing is that we got what we wanted, and there won’t be any surprises later. Now for some pictures… This 6”+ pry bar made the destruction of the old deck much easier Most of the joists, once exposed, were OK. This joist wasn’t sitting on ANYTHING before. We think a lazy gas person cut the board to sneak a gas line in. Awesome… These monster lag bolts had to be accounted for when putting in the additional framing The border pattern Sheri wanted to put in required a lot more framing. These were the first boards to go down – we screwed them in as there was no way to attach clips I sat, kicked in the boards, and then drilled these clips in – but my wife was able to go MUCH faster by using her hands to lock the boards in and drill on her knees. I liked locking the board in with my feet when they needed to be ‘encouraged’ to go straight. The first board took FOREVER to go in, but then when we got rolling, we were able to put in a 20′ board in less than 10 minutes. This was end of construction day #2 – we got much further than we thought we would. Ah, the dreaded last 10% – what to do here? Remember those ‘floating’ stringers? Yeah, we fixed that up a bit, too. My wife used a website (and her brain) to calculate exactly how to cut the stringers to give us the rise/run we needed with the proper clearance and all that jazz. The stairs with stringers and toe kicks – this was worth the effort It started raining on us as I screwed down the steps – this we managed to get our shade tent up on the deck to protect us from the rain too The stairs, finished Finished, mostly Good corner shot The top of the stairs Stairs, looking down Celebratory beer In Summary There are a few things we’re not happy with. I think we can fix them up – but later. I have a few things left to finish, rewire the lighting, get the gas grille put back in, and rehang some screen doors. I was expecting this to be a lot worse than it was. If I didn’t have the help, I would have never done it myself. But I’m glad that I did have that help and did do that project. It’s not often you get to spend that kind of qualify time with family and building cool stuff.

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• elffile: ELF Specific File Identification Utility

  - by user9154181

  Solaris 11 has a new standard user level command, /usr/bin/elffile. elffile is a variant of the file utility that is focused exclusively on linker related files: ELF objects, archives, and runtime linker configuration files. All other files are simply identified as "non-ELF". The primary advantage of elffile over the existing file utility is in the area of archives — elffile examines the archive members and can produce a summary of the contents, or per-member details. The impetus to add elffile to Solaris came from the effort to extend the format of Solaris archives so that they could grow beyond their previous 32-bit file limits. That work introduced a new archive symbol table format. Now that there was more than one possible format, I thought it would be useful if the file utility could identify which format a given archive is using, leading me to extend the file utility: % cc -c ~/hello.c % ar r foo.a hello.o % file foo.a foo.a: current ar archive, 32-bit symbol table % ar r -S foo.a hello.o % file foo.a foo.a: current ar archive, 64-bit symbol table In turn, this caused me to think about all the things that I would like the file utility to be able to tell me about an archive. In particular, I'd like to be able to know what's inside without having to unpack it. The end result of that train of thought was elffile. Much of the discussion in this article is adapted from the PSARC case I filed for elffile in December 2010: PSARC 2010/432 elffile Why file Is No Good For Archives And Yet Should Not Be Fixed The standard /usr/bin/file utility is not very useful when applied to archives. When identifying an archive, a user typically wants to know 2 things: Is this an archive? Presupposing that the archive contains objects, which is by far the most common use for archives, what platform are the objects for? Are they for sparc or x86? 32 or 64-bit? Some confusing combination from varying platforms? The file utility provides a quick answer to question (1), as it identifies all archives as "current ar archive". It does nothing to answer the more interesting question (2). To answer that question, requires a multi-step process: Extract all archive members Use the file utility on the extracted files, examine the output for each file in turn, and compare the results to generate a suitable summary description. Remove the extracted files It should be easier and more efficient to answer such an obvious question. It would be reasonable to extend the file utility to examine archive contents in place and produce a description. However, there are several reasons why I decided not to do so: The correct design for this feature within the file utility would have file examine each archive member in turn, applying its full abilities to each member. This would be elegant, but also represents a rather dramatic redesign and re-implementation of file. Archives nearly always contain nothing but ELF objects for a single platform, so such generality in the file utility would be of little practical benefit. It is best to avoid adding new options to standard utilities for which other implementations of interest exist. In the case of the file utility, one concern is that we might add an option which later appears in the GNU version of file with a different and incompatible meaning. Indeed, there have been discussions about replacing the Solaris file with the GNU version in the past. This may or may not be desirable, and may or may not ever happen. Either way, I don't want to preclude it. Examining archive members is an O(n) operation, and can be relatively slow with large archives. The file utility is supposed to be a very fast operation. I decided that extending file in this way is overkill, and that an investment in the file utility for better archive support would not be worth the cost. A solution that is more narrowly focused on ELF and other linker related files is really all that we need. The necessary code for doing this already exists within libelf. All that is missing is a small user-level wrapper to make that functionality available at the command line. In that vein, I considered adding an option for this to the elfdump utility. I examined elfdump carefully, and even wrote a prototype implementation. The added code is small and simple, but the conceptual fit with the rest of elfdump is poor. The result complicates elfdump syntax and documentation, definite signs that this functionality does not belong there. And so, I added this functionality as a new user level command. The elffile Command The syntax for this new command is elffile [-s basic | detail | summary] filename... Please see the elffile(1) manpage for additional details. To demonstrate how output from elffile looks, I will use the following files: FileDescription configA runtime linker configuration file produced with crle dwarf.oAn ELF object /etc/passwdA text file mixed.aArchive containing a mixture of ELF and non-ELF members mixed_elf.aArchive containing ELF objects for different machines not_elf.aArchive containing no ELF objects same_elf.aArchive containing a collection of ELF objects for the same machine. This is the most common type of archive. The file utility identifies these files as follows: % file config dwarf.o /etc/passwd mixed.a mixed_elf.a not_elf.a same_elf.a config: Runtime Linking Configuration 64-bit MSB SPARCV9 dwarf.o: ELF 64-bit LSB relocatable AMD64 Version 1 /etc/passwd: ascii text mixed.a: current ar archive, 32-bit symbol table mixed_elf.a: current ar archive, 32-bit symbol table not_elf.a: current ar archive same_elf.a: current ar archive, 32-bit symbol table By default, elffile uses its "summary" output style. This output differs from the output from the file utility in 2 significant ways: Files that are not an ELF object, archive, or runtime linker configuration file are identified as "non-ELF", whereas the file utility attempts further identification for such files. When applied to an archive, the elffile output includes a description of the archive's contents, without requiring member extraction or other additional steps. Applying elffile to the above files: % elffile config dwarf.o /etc/passwd mixed.a mixed_elf.a not_elf.a same_elf.a config: Runtime Linking Configuration 64-bit MSB SPARCV9 dwarf.o: ELF 64-bit LSB relocatable AMD64 Version 1 /etc/passwd: non-ELF mixed.a: current ar archive, 32-bit symbol table, mixed ELF and non-ELF content mixed_elf.a: current ar archive, 32-bit symbol table, mixed ELF content not_elf.a: current ar archive, non-ELF content same_elf.a: current ar archive, 32-bit symbol table, ELF 64-bit LSB relocatable AMD64 Version 1 The output for same_elf.a is of particular interest: The vast majority of archives contain only ELF objects for a single platform, and in this case, the default output from elffile answers both of the questions about archives posed at the beginning of this discussion, in a single efficient step. This makes elffile considerably more useful than file, within the realm of linker-related files. elffile can produce output in two other styles, "basic", and "detail". The basic style produces output that is the same as that from 'file', for linker-related files. The detail style produces per-member identification of archive contents. This can be useful when the archive contents are not homogeneous ELF object, and more information is desired than the summary output provides: % elffile -s detail mixed.a mixed.a: current ar archive, 32-bit symbol table mixed.a(dwarf.o): ELF 32-bit LSB relocatable 80386 Version 1 mixed.a(main.c): non-ELF content mixed.a(main.o): ELF 64-bit LSB relocatable AMD64 Version 1 [SSE]

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