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• How to manage a Closed Source High-Risk Project?

  - by abel

  I am currently planning to develop a J2EE website and wish to bring in 1 developer and 1 web designer to assist me. The project is a financial app with a niche market. I plan to keep the source closed . However, I fear that my would-be employees could easily copy the codebase and use it /sell it to a third party especially when they switch jobs. The app development will take 4-6months and perhaps more and I may have to bring in people after the app goes live. How do I keep the source to myself. Are there techniques companies use to guard their source. I foresee disabling pendrives and dvd writers on my development machines, but uploading data or attaching the code in one's mail would still be possible. My question is incomplete. But programmers who have been in my situation, please advice. How should I go about this? Building a team, maintaining code-secrecy,etc. I am looking forward to sign a secrecy contract with the employees if needed too. (Please add relevant tags) Update Thank you for all the answers. I certainly won't be disabling all USB ports and DVD writers now. But I think I should be logging activity(How exactly should I do that?) I am wary of scalpers who would join and then run off with the existing code. I haven't met any, but I have been advised to be wary of them. I would include a secrecy clause, but given this is a startup with almost no funding and in a highly competitive business niche with bigger players in the field, I doubt I would be able to detect or pursue any scalpers. How do I hire people I trust, when I don't know them personally. Their resume will be helpful but otherwise trust will develop only with time. But finally even if they do run away with the code, it is service that matters after the sale is made. So I am not really worried for the long term.

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• How do I maintain a really poorly written code base?

  - by onlineapplab.com

  Recently I got hired to work on existing web application because of NDA I'm not at liberty to disclose any details but this application is working online in sort of a beta testing stage before official launch. We have a few hundred users right now but this number is supposed to significantly increase after official launch. The application is written in PHP (but it is irrelevant to my question) and is running on a dual xeon processor standalone server with severe performance problems. I have seen a lot of bad PHP code but this really sets new standards, especially knowing how much time and money was invested in developing it. it is as badly coded as possible there is PHP, HTML, SQL mixed together and code is repeated whenever it is necessary (especially SQL queries). there are not any functions used, not mentioning any OOP there are four versions of the app (desktop, iPhone, Android + other mobile) each version has pretty much the same functionality but was created by copying the whole code base, so now there are some differences between each version and it is really hard to maintain the database is really badly designed, which is causing severe performance problems also for fixing some errors in PHP code there is a lot of database triggers used which are updating data on SELECT and on INSERT so any testing is a nightmare Basically, any sin of a bad programming you can imagine is there for example it is not only possible to use SQL injections in literally every place but you can log into app if you use a login which doesn't exist and an empty password. The team which created this app is not working on it any more and there is an outsourced team which suggested that there are some problems but was never willing to deal with the elephant in the room partially because they've got a very comfortable contract and partially due to lack of skills (just my opinion). My job was supposed to be fixing some performance problems and extending existing functionality but first thing I was asked to do was a review of the existing code base. I've made my review and it was quite a shock for the management but my conclusions were after some time finally confirmed by other programmers. Management made it clear that it is not possible to start rewriting this app from scratch (which in my opinion should be done). We have to maintain its operable state and at the same time fix performance errors and extend the functionality. My question is, as I don't want just to patch the existing code, how to transform this into properly written app while keeping the existing code working at the same time? My plan is: Unify four existing versions into common code base (fixing only most obvious errors). Redesign db and use triggers to populate it with data (so data will be maintained in two formats at the same time) All new functionality will be written as separate project. Step by step transfer existing functionality into the new project After some time everything will be in the new project Some explanation about #2, right now it is practically impossible to make any updates in existing db any change requires reviewing whole code and making changes in many places. Is such plan feasible at all? Another solution is to walk away and leave the headache to someone else.

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• Should EICAR be updated to test the revision of Antivirus system?

  - by makerofthings7

  I'm posting this here since programmers write viruses, and AV software. They also have the best knowledge of heuristics and how AV systems work (cloaking etc). The EICAR test file was used to functionally test an antivirus system. As it stands today almost every AV system will flag EICAR as being a "test" virus. For more information on this historic test virus please click here. Currently the EICAR test file is only good for testing the presence of an AV solution, but it doesn't check for engine file or DAT file up-to-dateness. In other words, why do a functional test of a system that could have definition files that are more than 10 years old. With the increase of zero day threats it doesn't make much sense to functionally test your system using EICAR. That being said, I think EICAR needs to be updated/modified to be effective test that works in conjunction with an AV management solution. This question is about real world testing, without using live viruses... which is the intent of the original EICAR. That being said I'm proposing a new EICAR file format with the appendage of an XML blob that will conditionally cause the Antivirus engine to respond. X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-EXTENDED-ANTIVIRUS-TEST-FILE!$H+H* <?xml version="1.0"?> <engine-valid-from>2010-1-1Z</engine-valid-from> <signature-valid-from>2010-1-1Z</signature-valid-from> <authkey>MyTestKeyHere</authkey> In this sample, the antivirus engine would only alert on the EICAR file if both the signature or engine file is equal to or newer than the valid-from date. Also there is a passcode that will protect the usage of EICAR to the system administrator. If you have a backgound in "Test Driven Design" TDD for software you may get that all I'm doing is applying the principals of TDD to my infrastructure. Based on your experience and contacts how can I make this idea happen?

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• Interesting Topics in Comp. Sci. for New Students?

  - by SoulBeaver

  I hope this is the right forum to ask this question. Last friday I was in a discussion with my professors about the students' lack of motivation and interest in the field of Computer Science. All of the students are enrolled, but through questionnaires and other questions that my professor posed it was revealed that over 90% of all enrolled students are just in it for the reward of getting a job sometime in the future (since it's a growing field with high job potential) I asked my professor for the permission to take over the first couple of lectures and try and motivate, interest and inspire students for the field of Computer Science and programming in particular (this is the Intro to Programming course). This request was granted and I now have a week to come up with a lecture topic for my professor's five groups. My main goal isn't to teach, I just want to get students to be as interested in the field as I am. I want to show them what's possible, what awesome magical things have been done in the field, the future we are heading towards using programming and Comp. Sci. Therefore, I would like to pose this question: I have a few topics, materials and sample projects that I would like to talk about: -- Grace Hopper (It is my hope to interest the female programmers in the class. There are never more than two or three per group and they, more than males, are prone to jumping ship and abandoning Comp. Sci.) -- The Singularity Institute -- Alan Turing -- Robotics -- Programming not as a chore or a must, but the idea that we are, at our core, the nexus to which anything anybody does in the digital world is connected to. We are the problem solvers; we assemble all the parts together and we are the ones that, essentially, make the vision a reality. -- Give them an idea for a programming project which, through the help of the professor, could be significant to every student (I want students to not only feel interested in the topic, but they should feel important, that what they do here makes a difference) Do you have interesting topics worthy of discussion, something I can tell the students which they can get interested about? How would you approach the lecture? If you had 90 minutes worth of time to try and get students interested in the project, what would you do?

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• Why do old programming languages continue to be revised?

  - by SunAvatar

  This question is not, "Why do people still use old programming languages?" I understand that quite well. In fact the two programming languages I know best are C and Scheme, both of which date back to the 70s. Recently I was reading about the changes in C99 and C11 versus C89 (which seems to still be the most-used version of C in practice and the version I learned from K&R). Looking around, it seems like every programming language in heavy use gets a new specification at least once per decade or so. Even Fortran is still getting new revisions, despite the fact that most people using it are still using FORTRAN 77. Contrast this with the approach of, say, the typesetting system TeX. In 1989, with the release of TeX 3.0, Donald Knuth declared that TeX was feature-complete and future releases would contain only bug fixes. Even beyond this, he has stated that upon his death, "all remaining bugs will become features" and absolutely no further updates will be made. Others are free to fork TeX and have done so, but the resulting systems are renamed to indicate that they are different from the official TeX. This is not because Knuth thinks TeX is perfect, but because he understands the value of a stable, predictable system that will do the same thing in fifty years that it does now. Why do most programming language designers not follow the same principle? Of course, when a language is relatively new, it makes sense that it will go through a period of rapid change before settling down. And no one can really object to minor changes that don't do much more than codify existing pseudo-standards or correct unintended readings. But when a language still seems to need improvement after ten or twenty years, why not just fork it or start over, rather than try to change what is already in use? If some people really want to do object-oriented programming in Fortran, why not create "Objective Fortran" for that purpose, and leave Fortran itself alone? I suppose one could say that, regardless of future revisions, C89 is already a standard and nothing stops people from continuing to use it. This is sort of true, but connotations do have consequences. GCC will, in pedantic mode, warn about syntax that is either deprecated or has a subtly different meaning in C99, which means C89 programmers can't just totally ignore the new standard. So there must be some benefit in C99 that is sufficient to impose this overhead on everyone who uses the language. This is a real question, not an invitation to argue. Obviously I do have an opinion on this, but at the moment I'm just trying to understand why this isn't just how things are done already. I suppose the question is: What are the (real or perceived) advantages of updating a language standard, as opposed to creating a new language based on the old?

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• Criteria for selecting timeout value?

  - by stijn

  Situation: a piece of software reads frames of data from a file in a seperate thread and puts it on a queue, emptied by another thread. That second thread periodically checks on the queue and fails rather gracefully, by showing an error message stating the read timed out, if no data is available within a certain amount of time. Initially this timeout was set to 200mSec. There was no real reasoning behind that constant though, but it worked fine. We measured on a couple of machines and for large data frames, larger than what would be used by customers, a read took like 20mSec whith no other load on the machine. However one customer now gets timeout errors now and then (on the second try all is fine, probably the file is in cache or the virus scanner leaves it alone). The programmers are like 'well, yeah, but that customer's machine is full of cruft, virus scanners, tons of unneeded background processes etc'. Of course the customer is like 'hey this should just work, shouldn't it'? While the programers have a point, since the software is heavy enough to validate the need for a dedicated machine, that does not make the customer happy. Increasing the timeout to 2 seconds, for example, solves the problem. But I'd like to make a proper decision now instead of just randomly pick some magic constant that is probably ok in 99% of cases. What criteria should be used for that? We could just pick a large number, but that feels wrong. (and then we end up with a program that has the horrible bahaviour of hanging when trying to read from a disconnected drive for instance, whereas we'd rather make it show an error right away). Or we could make the timeout value a user setting, but then we need to ducument it clearly and even then not all customers are tech savy enough to really understand what it does. Or we could try and wait until another customer reports timeouts and increase the value again. And again. Until we find something ok for 99.99% of the cases.. Any good practice for this type of situation?

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• Good, simple reasons for having multiple environments

  - by smp7d

  Throughout my career I had worked at companies that had a collection of different environments for different purposes. We always had more or less our desktop environment, a test environment, a QA environment, a staging environment and a production environment. This went for both servers/applications and any data sources we were using. When I started at my current company I found that 90% of the apps were either developed on a desktop environment against production data sources or developed directly on the production server depending on the platform. I wasn't fazed because I was hired in part to make changes to improve the way the development team functioned, which was clear from my interview process. We slowly started to turn the philosophy and pretty soon, most of the apps could be run in either a desktop, test or production environment. Not too long after that staging came around as well. Now most of our developers see the benefit of this methodology and defend it vigilantly. However, we have a number of legacy apps that never got migrated. We also have a number of legacy programmers who think of this as a waste of time. Unfortunately, we got lip service but never full buy-in from management. We got what we thought was a commitment to invest substantially in this about a year ago, but nothing materialized despite the considerable planning that we put into it. Now we are finding that we need more and more environments. We need help from the server/network administration teams for setup and we need participation from the business stakeholders to support the release cycle. We are at a place now where a project can function what I consider "normally" only if you have the right people on the project and the time to set up the proper environments. I'd love to present a complete argument, but management really has no time and interest in hearing me out until there is a critical issue. I can't really articulate the benefits simply as it always just seemed second nature to me. I was wondering if there are any good, simple, irrefutable reasons for the separation of environments that would get managers with no development experience to get behind this idea. Are there any good resources/literature on the topic?

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• Legitimate use of the Windows "Documents" folder in programs.

  - by romkyns

  Anyone who likes their Documents folder to contain only things they place there knows that the standard Documents folder is completely unsuitable for this task. Every program seems to want to put its settings, data, or something equally irrelevant into the Documents folder, despite the fact that there are folders specifically for this job1. So that this doesn't sound empty, take my personal "Documents" folder as an example. I don't ever use it, in that I never, under any circumstances, save anything into this folder myself. And yet, it contains 46 folders and 3 files at the top level, for a total of 800 files in 500 folders. That's 190 MB of "documents" I didn't create. Obviously any actual documents would immediately get lost in this mess. My question is: can anything be done to improve the situation sufficiently to make "Documents" useful again, say over the next 5 years? Can programmers be somehow educated en-masse not to use it as a dumping ground? Could the OS start reporting some "fake" location hidden under AppData through the existing APIs, while only allowing Explorer and the various Open/Save dialogs to know where the "real" Documents folder resides? Or are any attempts completely futile or even unnecessary? 1For the record, here's a quick summary of the various standard directories that should be used instead of "Documents": RoamingAppData for user-specific data and settings. This is the directory to use for user-specific non-temporary data. Anything placed here will be available on any machine that a given user logs on to in networks where this is configured. Do not place large files here though, because they slow down login/logout in such environments. LocalAppData for user-and-machine-specific data and settings. This data differs for every user and every machine. This is also where very large user-specific data should be placed. ProgramData for machine-specific data and settings. These are the same regardless of which user is logged on, and will not roam to other machines in a network. GetTempPath for all files that may be wiped without loss of data when not in use. This is also the place for things like caches, because like temporary data, a cache does not need to be backed up. Place your huge cache here and you'll save your user some backup trouble. "Documents" itself should only ever be used if the user specified it manually by entering a path or selecting it in a Save dialog. That is the only time it is ever appropriate to save stuff in "Documents".

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• Should I continue to pursue programming based on my experience?

  - by El Be

  The reason I ask this question is because I am not sure my troubles come from a lack of confidence, or something much deeper like lack of passion. I'm hoping experienced programmers and developers can help identify the cause of my troubles. To be brief my undergraduate major was in Computer Science, but in a small school and I had the highest gpa in my year in computer science. The first time I ever programmed was once in the 5th grade (using logo) and when I was a freshman in college. I enjoyed programming when I was in school. Then I did an internships where I was expected to produce image processing software and program microchips. I was unsuccessful and produced little results and I hated the job, because I had to figure out everything for myself, did not have any help, and there was a lot of pressure to produce results. Although I tried I could not figure out what to do and was stuck all the time and made me dislike the job. When the internship ended I went to a PhD program for computer science at a prestigious computer science school. I had a very hard time with the course, met people who have been programming since they were 6 and made plenty of applications in their spare time (which I never did, although I tried). I even met many sophomores who understood more than I did. The combination of this and other things have made me feel that programming is not for me, but sometimes I consider a career in programming. I still consider programming as a career because of the career potential (not only just because of money). Based on my experience do you believe my confidence has just been shaken and I should continue to prepare for a programming career, or do you see a lack of passion and it would make it tough to continue programming. thank you for reading and for your advice Thank you for everyone's advice so far! Also: I dropped out of the ph.D program for computer science and switched to a master's in computer graphics. Its more applied, but I still find it hard to be motivated (due to either lack of confidence or passion), but since programming is such a big field I am looking for that niche area that I feel good programming in.

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• How should I land my next consulting gig? [closed]

  - by MrOodles

  For the last couple of years, I've been working on speculative projects, expanding my skillset with side work, and paying the bills while having a blast consulting for startups. However, for a number of personal reasons, I need to spend the next 6-9 months maximizing my cash income. I want to put this into effect starting in early August. So that means I have one month to put the necessary client list/portfolio/resume together to start making this happen. As a programmer, I am very proficient in building Django web apps. I can write the necessary SQL, python, javascript, and css to build every part of a Django app, and then do the system administration necessary to deploy on AWS using EC2. I can also rig up a CDN to work seemlessly with the app using S3 and Cloudfront. I have built GIS applications using GeoDjango and PostGIS, and I have constructed social video apps by implementing Encoding.com as a service to prepare raw video files for consumption on the web. I am also moderately proficient in programming PHP, Java, and C#. I have built web apps in PHP, and desktop apps in Java and C#. I have dabbled with Android applications and iPhone apps, but nothing I would show off. I have experience doing SEO, social media marketing, and content marketing. Many of my clients have needed their apps promoted after they were built, and I was always happy to oblige when I could. I have also worked with biometrics technology including fingerprints for government contractors. This was as much a business analyst role as it was a programming gig, as I had to help answer RFPs, make checklists, and work around reems and reems of regulations to build applications that met very large bureaucratic requirements. I only have two real requirements for my next gig(s): 1) Work remotely. I live in North East Ohio, and I don't plan on leaving, but I wouldn't mind traveling one or two weeks out of every month to service clients who need on-site help. 2) $60.00hr-$∞ USD contracting rate. So what should I do for the next 30 days to achieve this? Should I target some large company and learn the requisite buzzwords to impress them? Should I learn some new language or technology? Polish some skill that I already have? Should I build something using my current skillset, or with some new technology? Should I put a website for my consultancy together to market myself? Should I do that using latest technology x, y, and z? Or should I just slap something up on Tumblr? I'm willing to do anything (moral) over the next 4 weeks to put myself into a position to maximize my income, and I'm open to all and every idea Programmers users may have. Let me hear them.

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• Is my JavaScript/jQuery methodology good? [migrated]

  - by absentx

  I am seeking critique on what has become my normal methodology of writing JavaScript code. I have become heavily reliant on the jQuery library, but I think this has helped me learn the native language better also. Anyway, please critique the following style of JavaScript coding... Buried are a lot of questions of scope; if you could point out the strengths and weaknesses of this style I would appreciate it. var critique ={ start: function(){ globalness = 'GLOBAL-GLOBAL'; //Available to all critique's methods var notglobalness = 'LOCAL-LOCAL'; // Only available to critiques start method //Am I using the "method" teminology properly here?? $('#stuff').on('click','a.closer-target',function(){ $target = $(this); if($target.hasClass('active')){ $target.removeClass('active'); } else{ $target.addClass('active'); critique.madness($target); } }) console.log(notglobalness+': at least I am useful at home'); console.log('note here that: '+notglobalness+' is no longer available after this point, lets continue on:'); critique.madness(notglobalness); }, madness: function($e){ //Do a bunch of awesomeness with $e, //but continue to keep it seperate because you think its best to keep things isolated. //Send to the next function when complete here console.log('Here is globalness, which is still available from the start method of critique!! ' + globalness); console.log('Let us see if the globalness carries on to a new var object!!'); console.log('The locally isolated variable of NOTGLOBALNESS is available here, because it was passed to this method. Let us show it:'+$e); carryOn.start(); } } //end critique var carryOn={ start: function(){ console.log('any chance critique.globalness will work here??? lets see: ' +globalness); console.log('it absolutely does'); } } $(document).ready(critique.start); (I always struggle with which of the Stack Exchange sites is best to post "questions of theory" like this, but I think Programmers is the best, if not, as usual a mod will move it, etc...)

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• Collaborative work (small team) - Best practices

  - by LEM01

  I'm currently working in a very small team of programmers (2-3) and I'm looking for advices/best practices on how to organise our work. We're all working on the same application using PHP. Today we're kind of all working on our way. Today situation: List item that have to be worked on by each dev 1/week. What has to be done is defined at a high functional level (ex: Build the search engine for this product..) Commit / merge our individual branches (git) every week before the next meeting No real dev rules, no code review No test written (aouutch) Problems faced: Code quality issue: discovering someone else code is sometime tough (inline, variable+function+class names, spaces, comments..) Changes in already existing classes (impact on someone else work) Responsibility of each dev unclear: after getting someone else code and discover something messy, should I make the change? Should he make the change? How to plan those things,... What I'm looking for: Basically I'm looking into structuring the way we develop things in order to avoid frustration and improve overall quality. How to define coding standards (naming convention, code rules...)? Do you you any validation script to make sure code is valid before committing? Do you think that defining an architect role in the team is needed? Someone that would actually define what has to be developed during the next phase. By defining interfaces or class descriptions that have to be written. (Does it make sense in such a small team?) Today we're losing time into understanding what others did or tried to do, we're also losing time in discussion like "you should have done it that way! Why is this class doing that and not that..? Shouldn't we have a embedded class rather that this set of data...". I'm looking into a work process, maybe with more defined responsibilities and process in order to improve our performance. If you have experience, advices, best practices or anything to share that we could benefit from it will be much appreciated! Thanks a lot for your time!

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• Does OO, TDD, and Refactoring to Smaller Functions affect Speed of Code?

  - by Dennis

  In Computer Science field, I have noticed a notable shift in thinking when it comes to programming. The advice as it stands now is write smaller, more testable code refactor existing code into smaller and smaller chunks of code until most of your methods/functions are just a few lines long write functions that only do one thing (which makes them smaller again) This is a change compared to the "old" or "bad" code practices where you have methods spanning 2500 lines, and big classes doing everything. My question is this: when it call comes down to machine code, to 1s and 0s, to assembly instructions, should I be at all concerned that my class-separated code with variety of small-to-tiny functions generates too much extra overhead? While I am not exactly familiar with how OO code and function calls are handled in ASM in the end, I do have some idea. I assume that each extra function call, object call, or include call (in some languages), generate an extra set of instructions, thereby increasing code's volume and adding various overhead, without adding actual "useful" code. I also imagine that good optimizations can be done to ASM before it is actually ran on the hardware, but that optimization can only do so much too. Hence, my question -- how much overhead (in space and speed) does well-separated code (split up across hundreds of files, classes, and methods) actually introduce compared to having "one big method that contains everything", due to this overhead? UPDATE for clarity: I am assuming that adding more and more functions and more and more objects and classes in a code will result in more and more parameter passing between smaller code pieces. It was said somewhere (quote TBD) that up to 70% of all code is made up of ASM's MOV instruction - loading CPU registers with proper variables, not the actual computation being done. In my case, you load up CPU's time with PUSH/POP instructions to provide linkage and parameter passing between various pieces of code. The smaller you make your pieces of code, the more overhead "linkage" is required. I am concerned that this linkage adds to software bloat and slow-down and I am wondering if I should be concerned about this, and how much, if any at all, because current and future generations of programmers who are building software for the next century, will have to live with and consume software built using these practices. UPDATE: Multiple files I am writing new code now that is slowly replacing old code. In particular I've noted that one of the old classes was a ~3000 line file (as mentioned earlier). Now it is becoming a set of 15-20 files located across various directories, including test files and not including PHP framework I am using to bind some things together. More files are coming as well. When it comes to disk I/O, loading multiple files is slower than loading one large file. Of course not all files are loaded, they are loaded as needed, and disk caching and memory caching options exist, and yet still I believe that loading multiple files takes more processing than loading a single file into memory. I am adding that to my concern.

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• Imperative vs. component based programming [closed]

  - by AlexW

  I've been thinking about how programming and more specifically the teaching of programming is advocated amongst the community (online). Often I've heard that Ruby and RoR is an ideal platform for learning to program. I completely disagree... RoR and Ruby are based on the application of the component based paradigm, which means they are ideal for rapid application development. This is much like the MVC model in PHP and ASP.NET But, learning a proper imperative language like Java or C/C++ (or even Perl and PHP) is the only way for a new programmer to explore logic itself, and not get too bogged down in architectural concerns like the need for separation of concerns, and the preference for components. Maybe it's a personal preference thing. I rather think that the most interesting aspects to programming are the procedural bits of code I write that actually do stuff rather than the project planning, and modelling that comes about from fully object oriented engineering or simply using the MVC model. I know this may sound confused to some of you. I feel strongly though that the best way for programming to be taught is through imperative and procedural methods. Architectural (component) methods come later, if at all. After all, none of the amazing algorithms that exist were based on OOP practice! It's all procedural code when it comes to the 'magic'. OOP is useful in creating products and utilities. Algorithms are what makes things happen, and move data around, and so imperative (and/or procedural) code are what matters most. When I see programmers recommending Ruby on Rails to newbie developers, I think it's just so wrong. Just because you write less code with Ruby does not make it easier to do! It's the opposite... you have to know loads more to appreciate its succinct nature. New coders who really want to understand the nuts and bolts of coding need to go away and figure out writing methods/functions (i.e. imperative programming) and working in procedural style, in order to grasp the fundamentals, first, before looking into architectural ways of working. So, my question is: should Ruby ever be recommended as a first language? I think no (obviously)... what arguments are there for it?

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• Why C++ people loves multithreading when it comes to performances?

  - by user1849534

  I have a question, it's about why programmers seems to love concurrency and multi-threaded programs in general. I'm considering 2 main approach here: an async approach basically based on signals, or just an async approach as called by many papers and languages like the new C# 5.0 for example, and a "companion thread" that maanges the policy of your pipeline a concurrent approach or multi-threading approach I will just say that I'm thinking about the hardware here and the worst case scenario, and I have tested this 2 paradigms myself, the async paradigm is a winner at the point that I don't get why people 90% of the time talk about concurrency when they wont to speed up things or make a good use of their resources. I have tested multi-threaded programs and async program on an old machine with an Intel quad-core that doesn't offer a memory controller inside the CPU, the memory is managed entirely by the motherboard, well in this case performances are horrible with a multi-threaded application, even a relatively low number of threads like 3-4-5 can be a problem, the application is unresponsive and is just slow and unpleasant. A good async approach is, on the other hand, probably not faster but it's not worst either, my application just waits for the result and doesn't hangs, it's responsive and there is a much better scaling going on. I have also discovered that a context change in the threading world it's not that cheap in real world scenario, it's infact quite expensive especially when you have more than 2 threads that need to cycle and swap among each other to be computed. On modern CPUs the situation it's not really that different, the memory controller it's integrated but my point is that an x86 CPUs is basically a serial machine and the memory controller works the same way as with the old machine with an external memory controller on the motherboard. The context switch is still a relevant cost in my application and the fact that the memory controller it's integrated or that the newer CPU have more than 2 core it's not bargain for me. For what i have experienced the concurrent approach is good in theory but not that good in practice, with the memory model imposed by the hardware, it's hard to make a good use of this paradigm, also it introduces a lot of issues ranging from the use of my data structures to the join of multiple threads. Also both paradigms do not offer any security abut when the task or the job will be done in a certain point in time, making them really similar from a functional point of view. According to the X86 memory model, why the majority of people suggest to use concurrency with C++ and not just an async aproach ? Also why not considering the worst case scenario of a computer where the context switch is probably more expensive than the computation itself ?

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• Why can't Java/C# implement RAII?

  - by mike30

  Question: Why can't Java/C# implement RAII? Clarification: I am aware the garbage collector is not deterministic. So with the current language features it is not possible for an object's Dispose() method to be called automatically on scope exit. But could such a deterministic feature be added? My understanding: I feel an implementation of RAII must satisfy two requirements: 1. The lifetime of a resource must be bound to a scope. 2. Implicit. The freeing of the resource must happen without an explicit statement by the programmer. Analogous to a garbage collector freeing memory without an explicit statement. The "implicitness" only needs to occur at point of use of the class. The class library creator must of course explicitly implement a destructor or Dispose() method. Java/C# satisfy point 1. In C# a resource implementing IDisposable can be bound to a "using" scope: void test() { using(Resource r = new Resource()) { r.foo(); }//resource released on scope exit } This does not satisfy point 2. The programmer must explicitly tie the object to a special "using" scope. Programmers can (and do) forget to explicitly tie the resource to a scope, creating a leak. In fact the "using" blocks are converted to try-finally-dispose() code by the compiler. It has the same explicit nature of the try-finally-dispose() pattern. Without an implicit release, the hook to a scope is syntactic sugar. void test() { //Programmer forgot (or was not aware of the need) to explicitly //bind Resource to a scope. Resource r = new Resource(); r.foo(); }//resource leaked!!! I think it is worth creating a language feature in Java/C# allowing special objects that are hooked to the stack via a smart-pointer. The feature would allow you to flag a class as scope-bound, so that it always is created with a hook to the stack. There could be a options for different for different types of smart pointers. class Resource - ScopeBound { /* class details */ void Dispose() { //free resource } } void test() { //class Resource was flagged as ScopeBound so the tie to the stack is implicit. Resource r = new Resource(); //r is a smart-pointer r.foo(); }//resource released on scope exit. I think implicitness is "worth it". Just as the implicitness of garbage collection is "worth it". Explicit using blocks are refreshing on the eyes, but offer no semantic advantage over try-finally-dispose(). Is it impractical to implement such a feature into the Java/C# languages? Could it be introduced without breaking old code?

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• Can we have 2 'extension_dir' in php.ini?

  - by Nyxynyx

  When I installed pdo-pgsql, the extension was installed into /usr/lib/php/extensions/no-debug-non-zts-20090626/ and thus not automatically loaded. In php.ini, I have extension_dir = "/usr/local/lib/php/extensions/no-debug-non-zts-20090626" already defined. Snippet of php.ini ; Directory in which the loadable extensions (modules) reside. extension_dir = "/usr/local/lib/php/extensions/no-debug-non-zts-20090626" zend_extension = "/usr/local/IonCube/ioncube_loader_lin_5.3.so" zend_extension = "/usr/local/Zend/lib/Guard-5.5.0/php-5.3.x/ZendGuardLoader.so" extension = "eaccelerator.so" extension = "pdo.so" extension = "pdo_pgsql.so" extension = "pdo_sqlite.so" extension = "sqlite.so" extension = "pdo_mysql.so" Modified to work ; Directory in which the loadable extensions (modules) reside. extension_dir = "/usr/local/lib/php/extensions/no-debug-non-zts-20090626" extension_dir = "/usr/lib/php/extensions/no-debug-non-zts-20090626" zend_extension = "/usr/local/IonCube/ioncube_loader_lin_5.3.so" zend_extension = "/usr/local/Zend/lib/Guard-5.5.0/php-5.3.x/ZendGuardLoader.so" extension = "eaccelerator.so" extension = "pdo.so" extension = "pdo_pgsql.so" extension = "pdo_sqlite.so" extension = "sqlite.so" extension = "pdo_mysql.so" Why did PECL install pdo-pgsql into the 2nd extension directory and not the first? Is it recommended to have 2 extension_dir as shown in the 2nd code snippet above?

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• Strange DNS issue with internal Windows DNS

  - by Brady

  I've encountered a strange issue with our internal Windows DNS infrastructure. We have a website hosted on Amazon EC2 with the DNS running on Amazon Route 53. In the publicly facing DNS we have the wildcard record setup as an A record Alias pointing to an AWS Elastic Load Balancer sitting in front of our EC2 instances. For those who are not aware, the A record Alias behaves like a CNAME record, however no extra lookup is required on the client side (See http://docs.amazonwebservices.com/Route53/latest/DeveloperGuide/CreatingAliasRRSets.html for more information). We have a secondary domain that has the www subdomain as a CNAME pointing to a subdomain on the primary domain, which resolves against the wildcard entry. For example the subdomain www.secondary.com is a CNAME to sub1.primary.com, but there is no explicit entry for sub1.primary.com, so it resolves to wildcard record. This setup work without issue publicly. The issue comes in our internal DNS at our corporate office where we use the same primary domain for some internal only facing sites. In this setup we have two Active Directory DNS servers with one Server 2003 and one Server 2008 R2 instance. The zone is an AD integrated zone, but it is not the AD domain. In the internal DNS we have the wildcard record pointing to a third external domain, that is also hosted on Route 53 with an A record Alias pointing to the same ELB instance. For example, *.primary.com is a CNAME to tertiary.com, so in effect you have www.secondary.com as a CNAME to *.primary.com, which is a CNAME to tertiary.com. In this setup, attempting to resolve www.secondary.com will fail. Clearing the cache on the Server 2003 instance will allow it to resolve once, but subsequent attempts will fail. It fails even with a clean cache against the 2008 R2 server. It seems that only Windows clients are affected. A Mac running OSX Mountain Lion does not experience this issue. I'm even able to replicate the issue using nslookup. Against the 2003 server, with a freshly cleaned cache, I recieve the appropriate response from www.secondary.com: Non-authoritative answer: Name: subdomain.primary.com Address: x.x.x.x (Public IP) Aliases: www.secondary.com Subsequent checks simply return: Non-authoritative answer: Name: www.secondary.com If you set the type to CNAME you get the appropriate responses all the time. www.secondary.com gives you: Non-authoritative answer: www.secondary.com canonical name = subdomain.primary.com And subdomain.primary.com gives you: subdomain.primary.com canonical name = tertiary.com And setting type back to A gives you the appropriate response for tertiary.com: Non-authoritative answer: Name: tertiary.com Address: x.x.x.x (Public IP) Against the 2008 R2 server things are a little different. Even with a clean cache, www.secondary.com returns just: Non-authoritative answer: Name: www.secondary.com The CNAME records are returned appropriately. www.secondary.com returns: Non-authoritative answer: www.secondary.com canonical name = subdomain.primary.com And subdomain.primary.com gives you: subdomain.primary.com canonical name = tertiary.com tertiary.com internet address = x.x.x.x (Public IP) tertiary.com AAAA IPv6 address = x::x (Public IPv6) And setting type back to A gives you the appropriate response for tertiary.com: Non-authoritative answer: Name: tertiary.com Address: x.x.x.x (Public IP) Requests directly against subdomain.primary.com work correctly.

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• Failover tmpfs mirroring. Am I doing it right?

  - by user45286

  My goal is to have a certain directory to be available as tmpfs. There will be some modifications during server uptime in this dir and those modifications must be synced to non-tmpfs persistent dir on HDD over rsync. After server boot the latest version from non-tmpfs persistent dir must be moved to tmpfs and rsync syncing to be started. I'm afraid that rsync will erase non-tmpfs backup if tmpfs dir will be empty.. I'm doing it in this way right now: create tmpfs partition in /etc/fstab cat /etc/rc.local (pseudocode) delete "tmpfs rsync" cronjob from /var/spool/cron/crontabs if there is any cp -r /path/to/non-tmpfs-backup /path/to/tmpfs/dir append /var/spool/cron/crontabs with "tmpfs rsync" cronjob What do you think?

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• Make interchangeable class types via pointer casting only, without having to allocate any new objects?

  - by HostileFork

  UPDATE: I do appreciate "don't want that, want this instead" suggestions. They are useful, especially when provided in context of the motivating scenario. Still...regardless of goodness/badness, I've become curious to find a hard-and-fast "yes that can be done legally in C++11" vs "no it is not possible to do something like that". I want to "alias" an object pointer as another type, for the sole purpose of adding some helper methods. The alias cannot add data members to the underlying class (in fact, the more I can prevent that from happening the better!) All aliases are equally applicable to any object of this type...it's just helpful if the type system can hint which alias is likely the most appropriate. There should be no information about any specific alias that is ever encoded in the underlying object. Hence, I feel like you should be able to "cheat" the type system and just let it be an annotation...checked at compile time, but ultimately irrelevant to the runtime casting. Something along these lines: Node<AccessorFoo>* fooPtr = Node<AccessorFoo>::createViaFactory(); Node<AccessorBar>* barPtr = reinterpret_cast< Node<AccessorBar>* >(fooPtr); Under the hood, the factory method is actually making a NodeBase class, and then using a similar reinterpret_cast to return it as a Node<AccessorFoo>*. The easy way to avoid this is to make these lightweight classes that wrap nodes and are passed around by value. Thus you don't need casting, just Accessor classes that take the node handle to wrap in their constructor: AccessorFoo foo (NodeBase::createViaFactory()); AccessorBar bar (foo.getNode()); But if I don't have to pay for all that, I don't want to. That would involve--for instance--making a special accessor type for each sort of wrapped pointer (AccessorFooShared, AccessorFooUnique, AccessorFooWeak, etc.) Having these typed pointers being aliased for one single pointer-based object identity is preferable, and provides a nice orthogonality. So back to that original question: Node<AccessorFoo>* fooPtr = Node<AccessorFoo>::createViaFactory(); Node<AccessorBar>* barPtr = reinterpret_cast< Node<AccessorBar>* >(fooPtr); Seems like there would be some way to do this that might be ugly but not "break the rules". According to ISO14882:2011(e) 5.2.10-7: An object pointer can be explicitly converted to an object pointer of a different type.70 When a prvalue v of type "pointer to T1" is converted to the type "pointer to cv T2", the result is static_cast(static_cast(v)) if both T1 and T2 are standard-layout types (3.9) and the alignment requirements of T2 are no stricter than those of T1, or if either type is void. Converting a prvalue of type "pointer to T1" to the type "pointer to T2" (where T1 and T2 are object types and where the alignment requirements of T2 are no stricter than those of T1) and back to its original type yields the original pointer value. The result of any other such pointer conversion is unspecified. Drilling into the definition of a "standard-layout class", we find: has no non-static data members of type non-standard-layout-class (or array of such types) or reference, and has no virtual functions (10.3) and no virtual base classes (10.1), and has the same access control (clause 11) for all non-static data members, and has no non-standard-layout base classes, and either has no non-static data member in the most-derived class and at most one base class with non-static data members, or has no base classes with non-static data members, and has no base classes of the same type as the first non-static data member. Sounds like working with something like this would tie my hands a bit with no virtual methods in the accessors or the node. Yet C++11 apparently has std::is_standard_layout to keep things checked. Can this be done safely? Appears to work in gcc-4.7, but I'd like to be sure I'm not invoking undefined behavior.

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• Pagination, Duplicate Content, and SEO

  - by Iamtotallylost

  Please consider a list of items (forum comments, articles, shoes, doesn't matter) which are spread over multiple pages. Different sort orders are supported (by date, by popularity, by price, etc). So, an URL might look like this (I use the query style here to simplify things): /items?id=1234&page=42&sort=popularity /items?id=1234&page=5&sort=date Now, in terms of SEO, I think I should be worried about duplicate content. After all, each item appears at least as many times as there are sort orders. I've seen Matt Cutts talking about the rel=canonical link tag, but he also said that the canonical page should have very similar content. But this is not the case here because page #1 in a non-canonical sort order might have completely different items than page #1 in the canonical sort order. For a given non-canonical page, there is no clear canonical page listing all the same items, so I think rel=canonical won't help here. Then I thought about using the noindex meta tag on all pages with non-canonical sort order, and not using it on all pages with canonical sort order. However, if I use that method, what will happen with backlinks that are going to non-canonical pages -- will they still spread their page rank juice, even though the first page googlebot (or any other crawler) is going to encounter is marked as "noindex"? Can you please comment on my problem and what you think is the best solution? If you think you have a better solution, please consider that 1) I do not want to use Javascript for this, 2) I do not want all the items to be on one page. Thank you.

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• Free Certification Exams for Visual Studio 2010

  - by budugu

  Get promotional codes from herehttp://blogs.msdn.com/gerryo/archive/2010/03/17/register-for-visual-studio-2010-beta-exams.aspx You don’t have to pay anything to take these exams.  These are 100% free. If you pass the exam, you earn the certification just the same as if you took it in a non-beta environment. From Gerry O'Brien’s blog...  2) Is this a real exam? – Yes it is.  Even though the questions are not scored at the time you take the exam, they are real questions and the exam is real.  If you pass the exam, you earn the certification just the same as if you took it in a non-beta environment.  This means you don’t get a pass/fail or score immediately following the exam, but you do get notified 8 to 10 weeks later because we move slow in getting the final scoring in place.  4) What is the main difference between a beta and non-beta exam, besides cost? – The beta exam will show you questions that have not been through a final QA check.  You are that final QA check.  Non-beta exams expose you to 40 or 45 questions and you have a total of two hours to complete it.  The beta exam could expose you to as many as 125 to 150 questions and take up to four hours.   Following exams are for Asp.Net developers Exam 71-515, TS: Web Applications Development with Microsoft .NET Framework 4Exam 71-519: Pro: Designing and Developing Web Applications Using Microsoft .NET Framework 4

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• Lost in Translation

  - by antony.reynolds

  Using the Correct Character Set for the SOA Suite Database A couple of years ago I spent a wonderful week in Tel Aviv helping with the first Oracle BAM implementation in Israel.  Although everyone I interacted spoke better English than I did, the screens and data for the implementation were all in Hebrew, meaning the Hebrew alphabet.  Over the week I learnt to recognize a few Hebrew words, enough to enable me to test what we were doing.  So I knew SOA Suite worked OK with non-English and non-Latin character sets so I was suspicious recently when a customer was having data corruption of non-Latin characters.  On investigation it turned out that the data received correctly in the SOA Suite, but then it was corrupted after being stored in the database. A little investigation revealed that the customer was using the default database character set, which is “WE8ISO8859P1” which, as the name suggests only supports West European 8-bit characters.  What was happening was that when the customer had installed his SOA repository he had ignored the message that his database was not using AL32UTF as the character. After changing the character set on his database he no longer saw the corruption of non-English character data. So the moral of this story is Always install the SOA Repository in to an AL32UTF8 Database This is true for both SOA Suite 10g and 11g.  Ignore it at your peril, because you never know when you will need to support Hebrew, or Japanese or another multi-byte character set.

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• Multiline Replacement With Visual Studio

  - by Alois Kraus

  I had to remove some file headers in a bigger project which were all of the form #region File Header /*[ Compilation unit ----------------------------------------------------------       Name            : Class1.cs       Language        : C#     Creation Date   :      Description     : -----------------------------------------------------------------------------*/ /*] END */ #endregion I know that would be a cool thing to write a simple C# program use a recursive file search, read all lines skip the first n lines and write the files back to disc. But I wanted to test things first before I ruin my source files with one little typo. There comes the Visual Studio Search and Replace in Files dialog into the game. I can test my regular expression to do a multiline match with the Find button before actually breaking anything. And if something goes wrong I have the Undo button.   There is a nice blog post from Paulo Morgado online who deals with Multiline Regular expressions. The Visual Studio Regular expressions are non standard so you have to adapt your usual Regex know how to the other patterns. The pattern I cam finally up with is \#region File Header:b*(.*\n)@\#endregion The Regular expression can be read as \#region File Header Match “#region File Header” \# Escapes the # character since it is a quantifier. :b* After this none or more spaces or tabs can follow (:b stands for space or tab) (.*\n)@ Match anything across lines in a non greedy way (the @ character makes it non greedy) to prevent matching too much until the #endregion somewhere in our source file. \#endregion Match everything until “#endregion” is found I had always knew that Visual Studio can do it but I never bothered to learn the non standard Regex syntax. This is powerful and it is inside Visual Studio since 2005!

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• What are some good resources for creating a game engine in XNA?

  - by Glasser

  I'm currently a student game programmer working on an indie project. We have a team of eleven people (five programmers, four artists, and two audio designers) aboard, all working hard to help design this game. We've been meeting for months now and so far we have a pretty buffed out Game Design Document as well as much audio/visual concept art. Our programmers are itching to progress on our own end. Each person in our programming team is well versed in C++, but is very familiar with C#. We have enough experience and skill that we're confident that we will be successful with our game, and we're looking to build our own game engine in XNA as it seems like it would be worth our time and effort in the end. The game itself will be a 2D beat 'em up style game to be released over xbox live and the PC. It's play style will be similar to that of Castle Crashers or Scott Pilgrim vs The World. We want to design the game engine to allow us to better implement our assets into the game as well as to simplify the creation of design elements/mechanics. Currently between our programmers, we have books such as "XNA 4.0" and "Game Coding Complete, Third Edition," but we'd still like more information on both XNA and (especially) building a game engine from scratch. What are any other good books, websites, or resources we could use to further map out and program our game engine?

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