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• Why do many software projects fail today?

  - by TomTom

  As long as there are software projects, the world is wondering why they fail so often. I would like to know if there is a list or something equivalent which shows how many software projects fail today. Would be nice if there would be a comparison over the last 20 - 30 years. You can also add your top reason why a software project fails. Mine is "Requirements are poor or not even existing." which includes also "No (real) customer / user involved". EDIT: It is nearly impossible to clearly define the term "fail". Let's say that fail means: The project was more than 10% over budget and time. In my opinion the 10% + / - is a good range for an offer / tender. EDIT: Until now (Feb 11) it seems that most posters agree that a fail of the project is basically a failure of the project management (whatever fail means). But IMHO it comes out, that most developers are not happy with this situation. Perhaps because not the manager get penalized when a project was not successful, but the lazy, incompetent developer teams? When I read the posts I can also hear-out that there is a big "gap" between the developer side and the managment side. The expectations (perhaps also the requirements) seem to be so different, that a project cannot be successful in the end (over time / budget; users are not happy; not all first-prio features implemented; too many bugs because developers were forced to implement in too short timeframes ...) I',m asking myself: How can we improve it? Or do we have the possibility to improve it? Everybody seems to be unsatisfied with the way it goes now. Can we close the gap between these two worlds? Should we (the developers) go on strike and fight for "high quality reqiurements" and "realistic / iteration based time shedules"? EDIT: Ralph Westphal and Stefan Lieser have founded a new "community" called: Clean-Code-Developer. The aim of the group is to bring more professionalism into software engineering. Independently if a developer has a degree or tons of years of experience you can be part of this movement. Clean Code Developers live principles like SOLID every day. A professional developer is the biggest reviewer of his own work. And he has an internal value system which helps him to improve and become better. Check it out on: Clean Code Developer EDIT: Our company is doing at the moment a thing called "Application Development and Maintenance Benchmarking". This is a service offered by IBM to get a feedback from someone external on your software engineering process quality etc. When we get the results, I will tell you more about it.

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• Get specifc value from JSon string using JSon.Net

  - by dean nolan

  I am trying to get a value from a JSon formatted string. It was to get album info from a website called Freebase. My result is like this: { "a0": { "code": "/api/status/error", "messages": [ { "code": "/api/status/error/mql/result", "info": { "count": 20, "result": [ { "album": [ { "name": "Definitely Maybe", "release_date": "1994-08-30" } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "Most Wanted Rock 1", "release_date": null } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "Alternative 90s", "release_date": null } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "Live Forever: Best of Britpop", "release_date": "2003-03-03" } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "The Best... In the World... Ever! Volume 5", "release_date": "1997-03-31" } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "Live 4 Ever", "release_date": "1998-06-29" } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "De Afrekening, Volume 8", "release_date": "1994" } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "Now That's What I Call Music! 33", "release_date": null } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "Q: Anthems", "release_date": null } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "The Best Anthems... Ever! Volume 2", "release_date": null } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "1995 Mercury Music Prize: Ten Albums of the Year", "release_date": null } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "Now That's What I Call Music! 1994", "release_date": null } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "Indie Top 20, Volume 21", "release_date": "1995" } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "Dad Rocks!", "release_date": "2006-06-05" } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "Untitled", "release_date": null } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "The Greatest Hits of 1994", "release_date": "1994-10" } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "Top of the Pops 2", "release_date": "2000-03-27" } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "Q: Anthems (disc 1)", "release_date": null } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "Jamie Oliver's Cookin'", "release_date": "2001" } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" }, { "album": [ { "name": "Killer Buzz", "release_date": "2001" } ], "artist": "Oasis", "name": "Live Forever", "type": "/music/track" } ] }, "message": "Unique query may have at most one result. Got 20", "path": "", "query": { "album": [ { "name": null, "release_date": null, "sort": "release_date" } ], "artist": "Oasis", "error_inside": ".", "name": "Live Forever", "type": "/music/track" } } ] }, "code": "/api/status/ok", "status": "200 OK", "transaction_id": "cache;cache04.p01.sjc1:8101;2010-03-30T18:04:20Z;0035" } I am looking to get the first album title, Definitely Maybe, from this list. I have tried parsing the string like this: JObject o = JObject.Parse(jsonString); string album = (string)o[""]; But no matter what I have tried I don't know what to put in those quotes. How would I get this specific value or be able to search for it? Thanks

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• Qt vs .NET - plz no n00bs who don't know wtf they're talking about [closed]

  - by Pirate for Profit

  Man in all these Qt vs. .NET discussions 90% these people don't know WTF they're talking about. Trying to get a real comparison chart going before we embark on a major fucking project. And yes I'm drunk, and yes I use cocaine. Event Handling In Qt the event handling system you just emit signals when something cool happens and then catch them in slots, for instance emit valueChanged(int percent, bool something); and void MyCatcherObj::valueChanged(int p, bool ok){} blocking them and disconnecting them when needed, doing it across threads... once you get the hang of it, it just seems a lot more natural and intuitive than the way the .NET event handling is set up (you know, object sender, CustomEventArgs e). And I'm not just talking about syntax, because in the end the .NET delegate crap is the bomb. I'm also talking about in more than just reflection (because, yes, .NET obviously has much stronger reflection capabilities). I'm talking about in the way the system feels to a human being. Qt wins hands down i m o. Basically, the footprints make more sense and you can visualize the project easier without the clunky event handling system. I wish I could it explain it better. The only thing is, I do love some of the ease of C# compared to C++ and .NET's assembly architecture. That is a big bonus for modular projects, which are a PITA to do in C++. Database Ease of Doing Crap Also what about datasets and database manipulations. I think .net wins here but I'm not sure. Threading/Conccurency How do you guys think of the threading? In .NET, all I've ever done is make like a list of master worker threads with locks. I like QConcurrentFramework, you don't worry about locks or anything, and with the ease of the signal slot system across threads it's nice to get notified about the progress of things. Memory Usage Also what do you think of the overall memory usage comparison. Is the .NET garbage collector pretty on the ball and quick compared to the instantaneous nature of native memory management? Or does it just let programs leak up a storm and lag the computer then clean it up when it's about to really lag? However, I am a n00b who doesn't know what I'm talking about, please school me on the subject.

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• ANTLR: using stringTemplate

  - by Kevin Won

  (I'm a Noob with Antlr)... I'm having difficulties getting my grammar with StringTemplates. Basically I'm trying to write a little DSL. I can get my grammar the way I want (it parses correctly), but I can't get the generation of the target code to work with templates. So here's a snippet of my grammar: grammar Pfig; options { output=template; language=CSharp2; } conf : globalName ; globalName : 'GlobalName:' ID -> localConf(name ={$ID.text}) ; I simplified it quite a bit just to get the essence across. Basically, when the lex/parse comes across `GlobalName: Foo' I want it to spit out text based on the StringTemplate called 'localConf'. Super straightforward. So now, let's fire up the parser in a test app and have it process an input file. // C# processing a file with the lex/parser. // the 'app.pfig' file just has one line that reads 'GlobalName: Bla' using (FileStream fs = File.OpenRead("c:\\app.pfig")) { PfigParser parser = new PfigParser(new CommonTokenStream( new PfigLexer(new ANTLRInputStream(fs)))); using (TextReader tr = File.OpenText("./Pfig.stg")) { parser.TemplateLib = new StringTemplateGroup(tr); } var parseResult = parser.conf(); string code = parseResult.Template.ToString(); // Fail: template is null } I can step through the parser code and see that it correctly identifies my text and applies the stringTemplate correctly. The problem is that since this 'globalName' rule is a subrule of 'conf' it doesn't get executed directly--the method just finds it and returns. But the calling 'Conf' method does not keep the return value from the subrule--it goes to thin air. This means that my resultant template on the last line is null. If I get rid of the 'conf' rule in my grammar and call 'globalName' directly, it will work (since it's the only rule on the stack). But I obviously want more than one rule. I've generated the parser in Java and it does the same thing: // antlr generated parser code public PfigParser.conf_return conf() // throws RecognitionException [1] { PfigParser.conf_return retval = new PfigParser.conf_return(); try { { PushFollow(FOLLOW_globalName_in_conf30); globalName(); // <- it calls globalName() but doesn't keep the return. state.followingStackPointer--; } retval.Stop = input.LT(-1); } // snip It's simple to see I don't get some basic concept with how the Template approach is supposed to work with Antlr. I'm quite sure this is my problem but I'm a loggerheads to know what I'm doing wrong... the examples I've seen don't really show real-world template emission of code.

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• How do I use the gravity vector to correctly transform scene for augmented reality?

  - by gpdawson

  I'm trying figure out how to get an OpenGL specified object to be displayed correctly according to the device orientation (ie. according to the gravity vector from the accelerometer, and heading from compass). The GLGravity sample project has an example which is almost like this (despite ignoring heading), but it has some glitches. For example, the teapot jumps 180deg as the device viewing angle crosses the horizon, and it also rotates spuriously if you tilt the device from portrait into landscape. This is fine for the context of this app, as it just shows off an object and it doesn't matter that it does these things. But it means that the code just doesn't work when you attempt to emulate real life viewing of an OpenGL object according to the device's orientation. What happens is that it almost works, but the heading rotation you apply from the compass gets "corrupted" by the spurious additional rotations seen in the GLGravity example project. Can anyone provide sample code that shows how to adjust correctly for the device orientation (ie. gravity vector), or to fix the GLGravity example so that it doesn't include spurious heading changes? //Clear matrix to be used to rotate from the current referential to one based on the gravity vector bzero(matrix, sizeof(matrix)); matrix[3][3] = 1.0; //Setup first matrix column as gravity vector matrix[0][0] = accel[0] / length; matrix[0][1] = accel[1] / length; matrix[0][2] = accel[2] / length; //Setup second matrix column as an arbitrary vector in the plane perpendicular to the gravity vector {Gx, Gy, Gz} defined by by the equation "Gx * x + Gy * y + Gz * z = 0" in which we arbitrarily set x=0 and y=1 matrix[1][0] = 0.0; matrix[1][1] = 1.0; matrix[1][2] = -accel[1] / accel[2]; length = sqrtf(matrix[1][0] * matrix[1][0] + matrix[1][1] * matrix[1][1] + matrix[1][2] * matrix[1][2]); matrix[1][0] /= length; matrix[1][1] /= length; matrix[1][2] /= length; //Setup third matrix column as the cross product of the first two matrix[2][0] = matrix[0][1] * matrix[1][2] - matrix[0][2] * matrix[1][1]; matrix[2][1] = matrix[1][0] * matrix[0][2] - matrix[1][2] * matrix[0][0]; matrix[2][2] = matrix[0][0] * matrix[1][1] - matrix[0][1] * matrix[1][0]; //Finally load matrix glMultMatrixf((GLfloat*)matrix);

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• Detect user logout / shutdown in Python / GTK under Linux - SIGTERM/HUP not received

  - by Ivo Wetzel

  OK this is presumably a hard one, I've got an pyGTK application that has random crashes due to X Window errors that I can't catch/control. So I created a wrapper that restarts the app as soon as it detects a crash, now comes the problem, when the user logs out or shuts down the system, the app exits with status 1. But on some X errors it does so too. So I tried literally anything to catch the shutdown/logout, with no success, here's what I've tried: import pygtk import gtk import sys class Test(gtk.Window): def delete_event(self, widget, event, data=None): open("delete_event", "wb") def destroy_event(self, widget, data=None): open("destroy_event", "wb") def destroy_event2(self, widget, event, data=None): open("destroy_event2", "wb") def __init__(self): gtk.Window.__init__(self, gtk.WINDOW_TOPLEVEL) self.show() self.connect("delete_event", self.delete_event) self.connect("destroy", self.destroy_event) self.connect("destroy-event", self.destroy_event2) def foo(): open("add_event", "wb") def ex(): open("sys_event", "wb") from signal import * def clean(sig): f = open("sig_event", "wb") f.write(str(sig)) f.close() exit(0) for sig in (SIGABRT, SIGILL, SIGINT, SIGSEGV, SIGTERM): signal(sig, lambda *args: clean(sig)) def at(): open("at_event", "wb") import atexit atexit.register(at) f = Test() sys.exitfunc = ex gtk.quit_add(gtk.main_level(), foo) gtk.main() open("exit_event", "wb") Not one of these succeeds, is there any low level way to detect the system shutdown? Google didn't find anything related to that. I guess there must be a way, am I right? :/ EDIT: OK, more stuff. I've created this shell script: #!/bin/bash trap test_term TERM trap test_hup HUP test_term(){ echo "teeeeeeeeeerm" >~/Desktop/term.info exit 0 } test_hup(){ echo "huuuuuuuuuuup" >~/Desktop/hup.info exit 1 } while [ true ] do echo "idle..." sleep 2 done And also created a .desktop file to run it: [Desktop Entry] Name=Kittens GenericName=Kittens Comment=Kitten Script Exec=kittens StartupNotify=true Terminal=false Encoding=UTF-8 Type=Application Categories=Network;GTK; Name[de_DE]=Kittens Normally this should create the term file on logout and the hup file when it has been started with &. But not on my System. GDM doesn't care about the script at all, when I relog, it's still running. I've also tried using shopt -s huponexit, with no success. EDIT2: Also here's some more information aboute the real code, the whole thing looks like this: Wrapper Script, that catches errors and restarts the programm -> Main Programm with GTK Mainloop -> Background Updater Thread The flow is like this: Start Wrapper -> enter restart loop while restarts < max: -> start program -> check return code -> write error to file or exit the wrapper on 0 Now on shutdown, start program return 1. That means either it did hanup or the parent process terminated, the main problem is to figure out which of these two did just happen. X Errors result in a 1 too. Trapping in the shellscript doesn't work. If you want to take a look at the actual code check it out over at GitHub: http://github.com/BonsaiDen/Atarashii

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• List of freely available programming books

  - by Karan Bhangui

  I'm trying to amass a list of programming books with opensource licenses, like Creative Commons, GPL, etc. The books can be about a particular programming language or about computers in general. Hoping you guys could help: Languages BASH Advanced Bash-Scripting Guide (An in-depth exploration of the art of shell scripting) C The C book C++ Thinking in C++ C++ Annotations How to Think Like a Computer Scientist C# .NET Book Zero: What the C or C++ Programmer Needs to Know About C# and the .NET Framework Illustrated C# 2008 (Dead Link) Data Structures and Algorithms with Object-Oriented Design Patterns in C# Threading in C# Common Lisp Practical Common Lisp On Lisp Java Thinking in Java How to Think Like a Computer Scientist Java Thin-Client Programming JavaScript Eloquent JavaScript Haskell Real world Haskell Learn You a Haskell for Great Good! Objective-C The Objective-C Programming Language Perl Extreme Perl (license not specified - home page is saying "freely available") The Mason Book (Open Publication License) Practical mod_perl (CreativeCommons Attribution Share-Alike License) Higher-Order Perl Learning Perl the Hard Way PHP Practical PHP Programming Zend Framework: Survive the Deep End PowerShell Mastering PowerShell Prolog Building Expert Systems in Prolog Adventure in Prolog Prolog Programming A First Course Logic, Programming and Prolog (2ed) Introduction to Prolog for Mathematicians Learn Prolog Now! Natural Language Processing Techniques in Prolog Python Dive Into Python Dive Into Python 3 How to Think Like a Computer Scientist A Byte of Python Python for Fun Invent Your Own Computer Games With Python Ruby Why's (Poignant) Guide to Ruby Programming Ruby - The Pragmatic Programmer's Guide Mr. Neighborly's Humble Little Ruby Book SQL Practical PostgreSQL x86 assembly Paul Carter's tutorial Lua Programming In Lua (for v5 but still largely relevant) Algorithms and Data Structures Algorithms Data Structures and Algorithms with Object-Oriented Design Patterns in Java Planning Algorithms Frameworks/Projects The Django Book The Pylons Book Introduction to Design Patterns in C++ with Qt 4 (Open Publication License) Version control The SVN Book Mercurial: The Definitive Guide Pro Git UNIX / Linux The Art of Unix Programming Linux Device Drivers, Third Edition Others Structure and Interpretation of Computer Programs The Little Book of Semaphores Mathematical Logic - an Introduction An Introduction to the Theory of Computation Developers Developers Developers Developers Linkers and loaders Beej's Guide to Network Programming Maven: The Definitive Guide I will expand on this list as I get comments or when I think of more :D Related: Programming texts and reference material for my Kindle What are some good free programming books? Can anyone recommend a free software engineering book? Edit: Oh I didn't notice the community wiki feature. Feel free to edit your suggestions right in!

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• Revisiting .NET, but what should I focus on?

  - by Wayne M

  After about a two-year hiatus, I'm brushing up on my .NET skills to find a .NET job (my previous two positions have very little development, or development using legacy technologies, so apart from a few very minor apps I have not touched .NET in close to two years). I'm aware of things like ASP.NET MVC, and I have previously read on things like NHibernate and DI/IOC, albeit I have yet to use them apart from very trivial "Hello World" type applications. I have a subscription to Rob Conery's Tekpub website and occasionally watch these videos when I have free time. My concern is this: I don't live in a very technical area. I would be surprised if any but the most tech-savvy companies have heard of, let alone use, ASP.NET MVC, NHibernate (or even LINQ/EF), or know about IoC. I would be willing to bet a large sum of money that 95% of the possible jobs I could obtain will use the following: Visual Source Safe, if any VCS at all ASP.NET 2.0 Webforms (3.5 if lucky) Raw ADO.NET on top of a very thin implementation of the Gateway pattern Stored Procedures in the database for most CRUD operations Gratuitous use of code-behind, with a Service layer if I'm lucky If I were extremely lucky, I might find a shop that has heard of ORMs and either uses one, or has wrote their own data abstraction. Also if I were lucky, the company would be using Model-View-Presenter. In light of this I'm not sure what I should focus on learning. Personally, I would prefer to be using the latest stuff - ASP.NET MVC, NHibernate, jQuery, WCF etc. Reality says I should go back to the basics, since it looks like most potential opportunities aren't going to be anywhere near the cutting edge, or anywhere close to it. And, as much as I would like to find a position and start to show the other developers the benefits, in my past experience this has usually resulted in my being fired for "not being a team player" and doing things the bad old way. So, I am curious how you would approach a situation like this? What should I focus on, in order to A) Reaquaint myself with .NET, and B) Prepare myself to obtain a .NET job again that is more than likely going to use techniques that I and most other knowledgeable developers will scoff at?

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• C++ vs Matlab vs Python as a main language for Computer Vision Postgraduate

  - by Hough

  Hi all, Firstly, sorry for a somewhat long question but I think that many people are in the same situation as me and hopefully they can also gain some benefit from this. I'll be starting my PhD very soon which involve the fields of computer vision, pattern recognition and machine learning. Currently, I'm using opencv (2.1) C++ interface and I especially like its powerful Mat class and the overloaded operations available for matrix and image seamless operations and transformations. I've also tried (and implemented many small vision projects) using opencv python interface (new bindings; opencv 2.1) and I really enjoy python's ability to integrate opencv, numpy, scipy and matplotlib. But recently, I went back to opencv C++ interface because I felt that the official python new bindings were not stable enough and no overloaded operations are available for matrices and images, not to mention the lack of machine learning modules and slow speeds in certain operations. I've also used Matlab extensively in the past and although I've used mex files and other means to speed up the program, I just felt that Matlab's performance was inadequate for real-time vision tasks, be it for fast prototyping or not. When the project becomes larger and larger, many tasks have to be re-written in C and compiled into Mex files increasingly and Matlab becomes nothing more than a glue language. Here comes the sub-questions: For postgrad studies in these fields (machine learning, vision, pattern recognition), what is your main or ideal programming language for rapid prototyping of ideas and testing algorithms contained in papers? For postgrad studies, can you list down the pros and cons of using the following languages? C++ (with opencv + gsl + svmlib + other libraries) vs Matlab (with all its toolboxes) vs python (with the imcomplete opencv bindings + numpy + scipy + matplotlib). Are there computer vision PhD/postgrad students here who are using only C++ (with all its availabe libraries including opencv) without even needing to resort to Matlab or python? In other words, given the current existing computer vision or machine learning libraries, is C++ alone sufficient for fast prototyping of ideas? If you're currently using Java or C# for your postgrad work, can you list down the reasons why they should be used and how they compare to other languages in terms of available libraries? What is the de facto vision/machine learning programming language and its associated libraries used in your university research group? Thanks in advance.

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• MSSQL: How to copy a file (pdf, doc, txt...) stored in a varbinary(max) field to a file in a CLR sto

  - by user193655

  I ask this question as a followup of this question. A solution that uses bcp and xp_cmdshell, that is not my desired solution, has been posted here: stackoverflow.com/questions/828749/ms-sql-server-2005-write-varbinary-to-file-system (sorry i cannot post a second hyperlink since my reputation is les than 10). I am new to c# (since I am a Delphi developer) anyway I was able to create a simple CLR stored procedures by following a tutorial. My task is to move a file from the client file system to the server file system (the server can be accessed using remote IP, so I cannot use a shared folder as destination, this is why I need a CLR stored procedure). So I plan to: 1) store from Delphi the file in a varbinary(max) column of a temporary table 2) call the CLR stored procedure to create a file at the desired path using the data contained in the varbinary(max) field Imagine I need to move C:\MyFile.pdf to Z:\MyFile.pdf, where C: is a harddrive on local system and Z: is an harddrive on the server. I provide the code below (not working) that someone can modify to make it work? Here I suppose to have a table called MyTable with two fields: ID (int) and DATA (varbinary(max)). Please note it doesn't make a difference if the table is a real temporary table or just a table where I temporarly store the data. I would appreciate if some exception handling code is there (so that I can manage an "impossible to save file" exception). I would like to be able to write a new file or overwrite the file if already existing. [Microsoft.SqlServer.Server.SqlProcedure] public static void VarbinaryToFile(int TableId) { using (SqlConnection connection = new SqlConnection("context connection=true")) { connection.Open(); SqlCommand command = new SqlCommand("select data from mytable where ID = @TableId", connection); command.Parameters.AddWithValue("@TableId", TableId); // This was the sample code I found to run a query //SqlContext.Pipe.ExecuteAndSend(command); // instead I need something like this (THIS IS META_SYNTAX!!!): SqlContext.Pipe.ResultAsStream.SaveToFile('z:\MyFile.pdf'); } } (one subquestion is: is this approach coorect or there is a way to directly pass the data to the CLR stored procedure so I don't need to use a temp table?) If the subquestion's answer is No, could you describe the approach of avoiding a temp table? So is there a better way then the one I describe above (=temp table + Stored procedure)? A way to directly pass the dataastream from the client application to the CLR stored procedure? (my files can be any size but also very big)

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• Java ReentrantReadWriteLocks - how to safely acquire write lock?

  - by Andrzej Doyle

  I am using in my code at the moment a ReentrantReadWriteLock to synchronize access over a tree-like structure. This structure is large, and read by many threads at once with occasional modifications to small parts of it - so it seems to fit the read-write idiom well. I understand that with this particular class, one cannot elevate a read lock to a write lock, so as per the Javadocs one must release the read lock before obtaining the write lock. I've used this pattern successfully in non-reentrant contexts before. What I'm finding however is that I cannot reliably acquire the write lock without blocking forever. Since the read lock is reentrant and I am actually using it as such, the simple code lock.getReadLock().unlock(); lock.getWriteLock().lock() can block if I have acquired the readlock reentrantly. Each call to unlock just reduces the hold count, and the lock is only actually released when the hold count hits zero. EDIT to clarify this, as I don't think I explained it too well initially - I am aware that there is no built-in lock escalation in this class, and that I have to simply release the read lock and obtain the write lock. My problem is/was that regardless of what other threads are doing, calling getReadLock().unlock() may not actually release this thread's hold on the lock if it acquired it reentrantly, in which case the call to getWriteLock().lock() will block forever as this thread still has a hold on the read lock and thus blocks itself. For example, this code snippet will never reach the println statement, even when run singlethreaded with no other threads accessing the lock: final ReadWriteLock lock = new ReentrantReadWriteLock(); lock.getReadLock().lock(); // In real code we would go call other methods that end up calling back and // thus locking again lock.getReadLock().lock(); // Now we do some stuff and realise we need to write so try to escalate the // lock as per the Javadocs and the above description lock.getReadLock().unlock(); // Does not actually release the lock lock.getWriteLock().lock(); // Blocks as some thread (this one!) holds read lock System.out.println("Will never get here"); So I ask, is there a nice idiom to handle this situation? Specifically, when a thread that holds a read lock (possibly reentrantly) discovers that it needs to do some writing, and thus wants to "suspend" its own read lock in order to pick up the write lock (blocking as required on other threads to release their holds on the read lock), and then "pick up" its hold on the read lock in the same state afterwards? Since this ReadWriteLock implementation was specifically designed to be reentrant, surely there is some sensible way to elevate a read lock to a write lock when the locks may be acquired reentrantly? This is the critical part that means the naive approach does not work.

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• How to use Bouncy Castle lightweight API with AES and PBE

  - by Adrian

  I have a block of ciphertext that was created using the JCE algorithim "PBEWithSHA256And256BitAES-CBC-BC". The provider is BouncyCastle. What I'd like to do it decrypt this ciphertext using the BouncyCastle lightweight API. I don't want to use JCE because that requires installing the Unlimited Strength Jurisdiction Policy Files. Documentation seems to be thin on the ground when it comes to using BC with PBE and AES. Here's what I have so far. The decryption code runs without exception but returns rubbish. The encryption code, String password = "qwerty"; String plainText = "hello world"; byte[] salt = generateSalt(); byte[] cipherText = encrypt(plainText, password.toCharArray(), salt); private static byte[] generateSalt() throws NoSuchAlgorithmException { byte salt[] = new byte[8]; SecureRandom saltGen = SecureRandom.getInstance("SHA1PRNG"); saltGen.nextBytes(salt); return salt; } private static byte[] encrypt(String plainText, char[] password, byte[] salt) throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException { Security.addProvider(new BouncyCastleProvider()); PBEParameterSpec pbeParamSpec = new PBEParameterSpec(salt, 20); PBEKeySpec pbeKeySpec = new PBEKeySpec(password); SecretKeyFactory keyFac = SecretKeyFactory.getInstance("PBEWithSHA256And256BitAES-CBC-BC"); SecretKey pbeKey = keyFac.generateSecret(pbeKeySpec); Cipher encryptionCipher = Cipher.getInstance("PBEWithSHA256And256BitAES-CBC-BC"); encryptionCipher.init(Cipher.ENCRYPT_MODE, pbeKey, pbeParamSpec); return encryptionCipher.doFinal(plainText.getBytes()); } The decryption code, byte[] decryptedText = decrypt(cipherText, password.getBytes(), salt); private static byte[] decrypt(byte[] cipherText, byte[] password, byte[] salt) throws DataLengthException, IllegalStateException, InvalidCipherTextException, InvalidKeyException, NoSuchAlgorithmException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException { BlockCipher engine = new AESEngine(); CBCBlockCipher cipher = new CBCBlockCipher(engine); PKCS5S1ParametersGenerator keyGenerator = new PKCS5S1ParametersGenerator(new SHA256Digest()); keyGenerator.init(password, salt, 20); CipherParameters keyParams = keyGenerator.generateDerivedParameters(256); cipher.init(false, keyParams); byte[] decryptedBytes = new byte[cipherText.length]; int numBytesCopied = cipher.processBlock(cipherText, 0, decryptedBytes, 0); return decryptedBytes; }

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• Cannot pull correct data from a Javascript array into an HTML form

  - by Isaac

  I am trying to return the description value of the corresponding author name and book title(that are typed in the text boxes). The problem is that the first description displays in the text area no matter what. <h1>Bookland</h1> <div id="bookinfo"> Author name: <input type="text" id="authorname" name="authorname"></input><br /> Book Title: <input type="text" id="booktitle" name="booktitle"></input><br /> <input type="button" value="Find book" id="find"></input> <input type="button" value="Clear Info" id="clear"></input><br /> <textarea rows="15" cols="30" id="destin"></textarea> </div> JavaScript: var bookarray = [{Author: "Thomas Mann", Title: "Death in Venice", Description: "One of the most famous literary works of the twentieth century, this novella embodies" + "themes that preoccupied Thomas Mann in much of his work:" + "the duality of art and life, the presence of death and disintegration in the midst of existence," + "the connection between love and suffering and the conflict between the artist and his inner self." }, {Author: "James Joyce", Title: "A portrait of the artist as a young man", Description: "This work displays an unusually perceptive view of British society in the early 20th century." + "It is a social comedy set in Florence, Italy, and Surrey, England." + "Its heroine, Lucy Honeychurch, struggling against straitlaced Victorian attitudes of arrogance, narroe mindedness and sobbery, falls in love - while on holiday in Italy - with the socially unsuitable George Emerson." }, {Author: "E. M. Forster", Title: "A room with a view", Description: "This book is a fictional re-creation of the Irish writer'sown life and early environment." + "The experiences of the novel's young hero,unfold in astonishingly vivid scenes that seem freshly recalled from life" + "and provide a powerful portrait of the coming of age of a young man ofunusual intelligence, sensitivity and character. " }, {Author: "Isabel Allende", Title: "The house of spirits", Description: "Allende describes the life of three generations of a prominent family in Chile and skillfully combines with this all the main historical events of the time, up until Pinochet's dictatorship." }, {Author: "Isabel Allende", Title: "Of love and shadows", Description: "The whole world of Irene Beltran, a young reporter in Chile at the time of the dictatorship, is destroyed when" + "she discovers a series of killings carried out by government soldiers." + "With the help of a photographer, Francisco Leal, and risking her life, she tries to come up with evidence against the dictatorship." }] function searchbook(){ for(i=0; i &lt; bookarray.length; i++){ if ((document.getElementById("authorname").value &amp; document.getElementById("booktitle").value ) == (bookarray[i].Author &amp; bookarray[i].Title)){ document.getElementById("destin").value =bookarray[i].Description return bookarray[i].Description } else { return "Not Found!" } } } document.getElementById("find").addEventListener("click", searchbook, false)

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• 2d trajectory planning of a spaceship with physics.

  - by egarcia

  I'm implementing a 2D game with ships in space. In order to do it, I'm using LÖVE, which wraps Box2D with Lua. But I believe that my question can be answered by anyone with a greater understanding of physics than myself - so pseudo code is accepted as a response. My problem is that I don't know how to move my spaceships properly on a 2D physics-enabled world. More concretely: A ship of mass m is located at an initial position {x, y}. It has an initial velocity vector of {vx, vy} (can be {0,0}). The objective is a point in {xo,yo}. The ship has to reach the objective having a velocity of {vxo, vyo} (or near it), following the shortest trajectory. There's a function called update(dt) that is called frequently (i.e. 30 times per second). On this function, the ship can modify its position and trajectory, by applying "impulses" to itself. The magnitude of the impulses is binary: you can either apply it in a given direction, or not to apply it at all). In code, it looks like this: def Ship:update(dt) m = self:getMass() x,y = self:getPosition() vx,vy = self.getLinearVelocity() xo,yo = self:getTargetPosition() vxo,vyo = self:getTargetVelocity() thrust = self:getThrust() if(???) angle = ??? self:applyImpulse(math.sin(angle)*thrust, math.cos(angle)*thrust)) end end The first ??? is there to indicate that in some occasions (I guess) it would be better to "not to impulse" and leave the ship "drift". The second ??? part consists on how to calculate the impulse angle on a given dt. We are in space, so we can ignore things like air friction. Although it would be very nice, I'm not looking for someone to code this for me; I put the code there so my problem is clearly understood. What I need is an strategy - a way of attacking this. I know some basic physics, but I'm no expert. For example, does this problem have a name? That sort of thing. Thanks a lot.

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• Multi-step Workflows: make Workflow A depend on results of Workflow B and/or Workflow C

  - by Joey

  I have been tasked with creating a Software Installation Approval section for our Intranet. When a person requests that a particular piece of software be installed on their workstation, we need to get IT approval and then business approval. Once those are obtained, it is to be installed. I am using Sharepoint Designer to do this. I have List A, where the user enters the information on the requested software. Workflow A then creates a Task in List B, which is then assigned to the IT approver. Workflow B works on List B on item creation, setting the due dates, titles, and other fields, and then pauses until the due date. The IT approver works with the business side and completes the task. Once List B task is complete, the item in List A should be marked as complete -- I have everything up to this point working fine. I want to make this more robust in 2 ways. As the only real option is to mark List B task as "completed", which essentially means "Approved", we have no way of really denying a request. What I want to add is the option to approve or deny a request through the task on List B -- if it is approved, I want the item in List A to continue to show "In Progress" with a custom status of "Approved", and I want to create a new task for software installation; once the installation task is marked as completed, then I want List A to show "Completed" with a status of "Installed". If it is denied, I want the item in List A to show as "Completed", with a status of "Denied". The problem is, I'm not even sure where to start making these modifications. Creating and modifying the custom status fields isn't that big of an issue -- I have messed around with this and I'm fairly confident I can do this easily. My main concern is that I know I will need a Workflow C, but I don't know where or how to trigger this to get the results I need. I've managed to get Workflows A and B working fine, but anything beyond this is really pushing the limit of my knowledge. It's probably obvious that I am rather new to Sharepoint workflows. I was very much thrust into this position and I am still feeling my way around. Thanks in advance for any help!

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• realtime logging

  - by Ion Todirel

  I have an application which has a loop, part of a "Scheduler", which runs at all time and is the heart of the application. Pretty much like a game loop, just that my application is a WPF application and it's not a game. Naturally the application does logging at many points, but the Scheduler does some sensitive monitoring, and sometimes it's impossible just from the logs to tell what may have gotten wrong (and by wrong I don't mean exceptions) or the current status. Because Scheduler's inner loop runs at short intervals, you can't do file I/O-based logging (or using the Event Viewer) in there. First, you need to watch it in real-time, and secondly the log file would grow in size very fast. So I was thinking of ways to show this data to the user in the realtime, some things I considered: Display the data in realtime in the UI Use AllocConsole/WriteConsole to display this information in a console Use a different console application which would display this information, communicate between the Scheduler and the console app using pipes or other IPC techniques Use Windows' Performance Monitor and somehow feed it with this information ETW Displaying in the UI would have its issues. First it doesn't integrate with the UI I had in mind for my application, and I don't want to complicate the UI just for this. This diagnostics would only happen rarely. Secondly, there is going to be some non-trivial data protection, as the Scheduler has it's own thread. A separate console window would work probably, but I'm still worried if it's not too much threshold. Allocating my own console, as this is a windows app, would probably be better than a different console application (3), as I don't need to worry about IPC communication, and non-blocking communication. However a user could close the console I allocated, and it would be problematic in that case. With a separate process you don't have to worry about it. Assuming there is an API for Performance Monitor, it wouldn't be integrated too well with my app or apparent to the users. Using ETW also doesn't solve anything, just a random idea, I still need to display this information somehow. What others think, would there be other ways I missed?

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• Google Streetview under V3 Code having hiccups and delays

  - by jeffkee

  http://new.brocksmeaton.com/showlisting.php/196/-7210-Arbutus-Place-Whytecliff-West-Vancouver-west-vancouver-real-estate The really odd thing is I had this working yesterday and today it's not working. I'm using jQuery UI to switch the tabs on the location map/street view module. I've recently upgraded the Google Maps code as well as the Google Streetview code to version 3. So when I open it in Firefox, with Firebug on, as soon as I switch to the Streetview tab, the navigation and zoom in out controls show, but nothing shows.. and then when I try to drag the map around, it does not move around, but instead, causes errors in Firebug: "too much recursion". So it causes the whole browser to become buggy, slows down, and the errors happen, and nothing shows on the streetview pane. Most of the map loading code is located in inline Javascript on the page itself. Some of the code is under showlisting.js <script type="text/javascript" src="/js/showlisting.js"></script> <script type="text/javascript"> // Call this function when the page has been loaded function loadmap() { var latlng = new google.maps.LatLng(49.374918567425475, -123.28996885871596); var myOptions = { zoom: 14, center: latlng, mapTypeId: google.maps.MapTypeId.ROADMAP }; var map = new google.maps.Map(document.getElementById('listingmap'), myOptions); var listingicon = '/images/activehouse.png'; var infowindow = new google.maps.InfoWindow(); homemarker = new google.maps.Marker({position: latlng, map: map, icon: listingicon}); google.maps.event.addListener(homemarker, 'click', function() { infowindow.setContent('<div style="height:80px; width:250px; color:#333;"><p>7210 Arbutus Place<br />Whytecliff, West Vancouver</div>') infowindow.open(map,homemarker); }); } function loadpano() { var latlng = new google.maps.LatLng(49.374918567425475, -123.28996885871596); $('#listingpanorama').slideDown(500, function() { var panoramaOptions = { addressControl:false, position: latlng, pov: { heading: 34, pitch: 30, zoom: 1 } }; var panorama = new google.maps.StreetViewPanorama(document.getElementById('listingpanorama'), panoramaOptions); }); return false; } </script> My old one under GOogle API Version 2 is here FYI if you want to take a look at it: http://demo.brixwork.com/master/showlisting.php/63/1701-388-Drake-Street-False-Creek-North-Vancouver-

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• Asp.NET MVC ActionFilter cannot get Form Submit data

  - by Goden

  I want to use custom action filter to manipulate parameters to one action. User inputs: 2 names in a form ; Action: actually needs to take 2 ids; Action Filter (onExecuting, will verify the input names and if valid, convert them into 2 ids and replace in the routedata) because i don't want to put validation logic in Action Controller. here's part of the code: Routing Info routes.MapRoute( "Default", // Route name "{controller}/{action}", // URL with parameters new { controller = "Home", action = "Index"} // Parameter defaults ); routes.MapRoute( "RelationshipResults", // Route Name "Relationship/{initPersonID}/{targetPersonID}", // URL with parameters new { controller = "Relationship", action = "Results" }); Form to submit (Create 2 input box and submit via jquery) <% using (Html.BeginForm("Results", "Relationship", FormMethod.Post, new { id = "formSearch" })) {% ... <td align="left"><%: MvcWeibookWeb.Properties.Resource.Home_InitPersonName%></td> <td align="right"> <%= Html.TextBox("initPersonName")%></td> <td rowspan="3" valign="top"> <div id="sinaIntro"> <%: MvcWeibookWeb.Properties.Resource.Home_SinaIntro %> <br /> <%: MvcWeibookWeb.Properties.Resource.Genearl_PromotionSina %> </div> </td> </tr> <tr> <td align="left" width="90px"><%: MvcWeibookWeb.Properties.Resource.Home_TargetPersonName%></td> <td align="right"><%= Html.TextBox("targetPersonName")%></td> </tr> <tr> <td colspan="2" align="right"> <a href="#" class="btn-HomeSearch" onclick="$('#formSearch').submit();"><%: MvcWeibookWeb.Properties.Resource.Home_Search%></a> </td> Action Filter public override void OnActionExecuting(ActionExecutingContext filterContext) { Sina.Searcher searcher = new Sina.Searcher(Sina.Processor.UserNetwork); String initPersonName, targetPersonName; // form submit names, we need to process them and convert them to IDs before it enters the real controller. initPersonName = filterContext.RouteData.Values["initPersonName"] as String; targetPersonName = filterContext.RouteData.Values["targetPersonName"] as String; // do sth to convert it to ids and replace Action/Controller [ValidationActionFilter] [HandleError] public ActionResult Results( Int64 initPersonName, Int64 targetPersonName) { ... My problem is: in the actionFilter, it never gets the 2 parameter "initPersonName" and "targetPersonName", the RouteData.Values don't contain these 2 keys... :(

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• javax.servlet.ServletException - how could i get to the cause?

  - by Michal

  Hi, i'm getting a very strange error while opening one of the pages in my web app. The application is built on Seam 2.2 and is using JSF (RichFaces) as a view technology. I run it on Tomcat 6. The error i'm describing doesn't occur on my machine (Mac OS X), but it does on my client's dev machines (Windows) and on the server (Linux Debian). I'm sure i'm running the same version on each system and i have tried connecting to the same database... In logs everything looks fine - each next JSF Phase executes normally, and after the last one, there is this moment when the request starts processing for the SEAM debug page... And this is the stack trace i see on the debug page (nothing is logged): Exception during request processing: Caused by javax.servlet.ServletException with message: "Servlet execution threw an exception" org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:313) org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:83) org.jboss.seam.web.IdentityFilter.doFilter(IdentityFilter.java:40) org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) org.jboss.seam.web.MultipartFilter.doFilter(MultipartFilter.java:90) org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) org.jboss.seam.web.ExceptionFilter.doFilter(ExceptionFilter.java:64) org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) org.jboss.seam.web.RedirectFilter.doFilter(RedirectFilter.java:45) org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) org.ajax4jsf.webapp.BaseXMLFilter.doXmlFilter(BaseXMLFilter.java:178) org.ajax4jsf.webapp.BaseFilter.handleRequest(BaseFilter.java:290) org.ajax4jsf.webapp.BaseFilter.processUploadsAndHandleRequest(BaseFilter.java:388) org.ajax4jsf.webapp.BaseFilter.doFilter(BaseFilter.java:515) org.jboss.seam.web.Ajax4jsfFilter.doFilter(Ajax4jsfFilter.java:56) org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) org.jboss.seam.web.LoggingFilter.doFilter(LoggingFilter.java:60) org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) org.jboss.seam.web.HotDeployFilter.doFilter(HotDeployFilter.java:53) org.jboss.seam.servlet.SeamFilter$FilterChainImpl.doFilter(SeamFilter.java:69) org.jboss.seam.servlet.SeamFilter.doFilter(SeamFilter.java:158) org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) pl.mgibowski.alterium.util.LoggingFilter.doFilter(LoggingFilter.java:18) org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235) org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:465) org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852) org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588) org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) java.lang.Thread.run(Thread.java:619) Exception without any cause... I was trying to catch the exception with my custom Filter (LoggingFilter.java that you can see on the strack trace), using this code: try { filterChain.doFilter(servletRequest, servletResponse); } catch (Throwable e) { e.printStackTrace(); System.out.println("Stack trace:"); System.out.println(e.getStackTrace()); System.out.println("Cause:"); System.out.println(e.getCause()); } But it doesn't catch anything, the line 18 from the stack trace is this one: filterChain.doFilter(servletRequest, servletResponse); nothing gets caught by the try block. Anybody has any ideas about how could i get closer to the real cause?

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• Save gcc compile status to a text file for Java

  - by JohnBore

  I'm making a C Assessment Program through Java, which has a bunch of programming questions for C, and it lets the user input an answer in the form of C code, and then press a "Compile" button, which is linked to a bat file that runs the user input code through gcc. I've got the input and compiling working, but I need to get the output from the compiler and get that to print textarea within the program. I can get a simple "Hello, world" compiling, but I'm having trouble getting programs that require a user input with scanf, for example, to be printed. else if(e.getSource().equals(compile)){ if(questionNumber<1){ JOptionPane.showMessageDialog(programFrame, "Please start the assessment", "Compile Error", JOptionPane.ERROR_MESSAGE); } else{ FileOutputStream fileWrite; try { fileWrite = new FileOutputStream("demo/demo.c"); new PrintStream(fileWrite).println(input.getText());//saves what the user has entered in to a C source file fileWrite.close(); @SuppressWarnings("unused") Process process = Runtime.getRuntime().exec("cmd /c compile.bat");//runs the batch file to compile the source file compileCode(); try{ fileStream = new FileInputStream("demo/output.txt"); inputStream = new DataInputStream(fileStream); bufferRead = new BufferedReader(new InputStreamReader(inputStream)); while((stringLine = bufferRead.readLine())!=null){ compiled.append(stringLine); compiled.append("\n"); } inputStream.close(); } catch(IOException exc){ System.err.println("Unable to read file"); System.exit(-1); } } catch (IOException exc) { JOptionPane.showMessageDialog(programFrame, "Demo file not found", "File Error", JOptionPane.ERROR_MESSAGE); } } This is the actionPerformed method for the "Compile" button, the compileCode() is the JFrame that displays the output and "compiled" is the textArea for the output. My batch file is: C: cd dev-cpp\bin gcc.exe H:\workspace\QuestionProgram\demo\demo.c -o demo > H:\workspace\QuestionProgram\demo\compilestatus.txt demo > H:\workspace\QuestionProgram\demo\output.txt I'm not sure how I can do it, so the frame is created for the output of the code if the code requires a user input as the command prompt doesn't open without adding "START" to .exec(), but then the frame appears before the program has finished running. Also, how would I get the output of the compiler if the compile fails because of an error? The way I've got it in my batch file at the moment doesn't put anything in a text file if it fails.

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• Log4r : logger inheritance, yaml configuration, alternatives ?

  - by devlearn

  Hello, I'm pretty new to ruby environments and I was looking for a nice logging framework to use it my ruby and rails applications. In my previous experiences I have successfully used log4j and log4p (the perl port) and was expecting the same level of usability (and maturity) with log4r. However I must say that there are a number of things that are not clear at all in the log4r framework. 1 Logger Inheritance The logger inheritance does not seem to be managed at all ! If I declare a logger named 'myapp' and then try to get a logger name 'myapp::engine', the lookup will end with a NameError. I would expect that the framework returns the root logger according to the naming scheme and to use the 'myapp' logger. Q1 : Of course I can work around this and manage the names by myself with a lookup method, however is there a cleaner way to do this without any extra coding ? 2 YAML configuration Second thing that confuses me is the yaml configuration. On the log4r site there are literally no information about this system, the doc links forward to missing pages, so all the info I can find about is contained in the examples directory of the gem. I was pretty confused with the fact that the yaml configuration must contain the pre_config section, and that I need to define my own levels. If I remove the pre_config secion, or replace all the “custom” levels by the standard ones ( debug, info, warn, fatal ) , the example will throw the following error : log4r/yamlconfigurator.rb:68:in `decode_yaml': Log level must be in 0..7 (ArgumentError) So there seems to be no way of using a simple file where we only declare the loggers and appenders for the framework. Q2 : I realy think that I missed something and that must be a way of providing a simple yaml conf file. Do you have any examples of such an usage ? 3 Variables substitution in XML file Q3 : The Yaml configuration system seems to provide such a feature however I was unable to find a similar feature with XML files. Any ideas ? 4 Alternatives ? I must say that I'm very disappointed by the feature level and the maturity of log4r compared to the log4j and other log4j ports. I run into this framework with a solid background of logging APIs in other languages and find myself working around in all kinds just to make 'basic things' running in a “real world application”. By that I mean a complex application composed of several gems, console/scripting apps, and a rails web front end where the configuration must be mutualized and where we make intensive usage of namespaces and inheritance. I've run several searches in order to find something more suitable or mature, but did not find anything similar. Q4 : Do you guys know any (serious) alternatives to log4r framework that could be used in a enterprise class app ? Thanks reading all of this ! I'd really appreciate any pointers, Kind Regards,

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• SSLException: Keystore does not support enabled cipher suites

  - by wurfkeks

  I want to implement a small android application, that works as SSL Server. After lot of problems with the right format of the keystore, I solved this and run into the next one. My keystore file is properly loaded by the KeyStore class. But when I try to open the server socket (socket.accept()) the following error is raised: javax.net.ssl.SSLException: Could not find any key store entries to support the enabled cipher suites. I generated my keystore with this command: keytool -genkey -keystore test.keystore -keyalg RSA -keypass ssltest -storepass ssltest -storetype BKS -provider org.bouncycastle.jce.provider.BouncyCastleProvider -providerpath bcprov.jar with the Unlimited Strength Jurisdiction Policy for Java SE6 applied to my jre6. I got a list of supported ciphers suites by calling socket.getSupportedCipherSuites() that prints a long list with very different combinations. But I don't know how to get a supported key. I also tried the android debug keystore after converting it to BKS format using portecle but get still the same error. Can anyone help and tell how I can generate a key that is compatible with one of the cipher suites? Version Information: targetSDK: 15 tested on emulator running 4.0.3 and real device running 2.3.3 BounceCastle 1.46 portecle 1.7 Code of my test application: public class SSLTestActivity extends Activity implements Runnable { SSLServerSocket mServerSocket; ToggleButton tglBtn; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); this.tglBtn = (ToggleButton)findViewById(R.id.toggleButton1); tglBtn.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { @Override public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) { if (isChecked) { new Thread(SSLTestActivity.this).run(); } else { try { if (mServerSocket != null) mServerSocket.close(); } catch (IOException e) { Log.e("SSLTestActivity", e.toString()); } } } }); } @Override public void run() { try { KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType()); keyStore.load(getAssets().open("test.keystore"), "ssltest".toCharArray()); ServerSocketFactory socketFactory = SSLServerSocketFactory.getDefault(); mServerSocket = (SSLServerSocket) socketFactory.createServerSocket(8080); while (!mServerSocket.isClosed()) { Socket client = mServerSocket.accept(); PrintWriter output = new PrintWriter(client.getOutputStream(), true); output.println("So long, and thanks for all the fish!"); client.close(); } } catch (Exception e) { Log.e("SSLTestActivity", e.toString()); } } }

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• Managed (.net) library with html-tidy like functionality?

  - by Eamon Nerbonne

  Does anybody know of an html cleaner for .NET that can parse html and (for instance) convert it to a more machine friendly format such as xhtml? I've tried the HTML Agility Pack, but that fails to correctly parse even fairly simple examples. To give an example of html that should be parsed correctly: <html><body> <ul><li>TestElem1 <li>TestElem2 <li>TestElem3 List: <ul><li>Nested1 <li>Nested2</li> <li>Nested3 </ul> <li>TestElem4 </ul> <p>paragraph 1 <p>paragraph 2 <p>paragraph 3 </body></html> li tags don't need to be closed (see spec), and neither do P tags. In other words, the above sample should be parsed as: <html><body> <ul><li>TestElem1</li> <li>TestElem2</li> <li>TestElem3 List: <ul><li>Nested1</li> <li>Nested2</li> <li>Nested3</li> </ul></li> <li>TestElem4</li> </ul> <p>paragraph 1</p> <p>paragraph 2</p> <p>paragraph 3</p> </body></html> Since the aim is to use the library on various machines, it's a big disadvantage to need to fall back to native code (such as a wrapper around html tidy) which would require extra deployment hassle and sacrifice platform independance. Any suggestions? To recap, I'm looking for: An html cleaner ala HTML tidy Must be able to deal with real world html, not just xhtml, at the very least correctly reading valid html 4 Must be able to convert to a more easily processable xml format Should be a purely managed app.

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• PHP5.3 is not working with MySQL5.1 IIS7 Times out

  - by Thorn007

  I have set up PHP5.3, MySQL5.1, and IIS7 on Window 7 but php doesn't want to work with MySQL. I'm assuming it is a configuration error or an incomplete install on my part. MySQL5.1 is working PHP5.3 is working, phpinfo() shows info and that i have enabled MySQL IIS is setup and using fastCgiModule to run PHP IIS registers php.ini updates port 3306 is firewall free and open to the world php.ini is configured correctly I have added c:\php to the Windows systems PATH In the past I remember moving a file, libmysql.dll, to System32 but I doesn't look like that come with php5.3.1, as the driver comes built in now http://us3.php.net/manual/en/mysqlnd.install.php. (This has been giving me so much trouble I have been documenting my findings on my blog as http://inteldesigner.com/2010/code/having-problems-getting-php5-3-to-work-with-mysql5-1 ) NEED: I need to install PHP manually, don't want to use the quick installer or an older version I need to get PHP5.3 to work with MySQL5.1 so i can install Wordpress2.9 and Drupal7a Any links or suggestion would be great, I have already done everything on the iis web site, nothing is working. I'm guessing they have not updated for new software. BUGS/SOLUTION: The solution is here: http://bugs.php.net/bug.php?id=50172 thanks go to don.raman on the iis.net forums http://forums.iis.net/p/1164911/1933894.aspx SYMPTOMS: The php function mysql_connect() in conjunction with php5.3 locks up sever and returns error 500. (IPv6 is the problem see above link) TEST CODE: <?php $con = mysql_connect("localhost","root","***"); if (!$con) { die('Could not connect: ' . mysql_error()); } // some code mysql_close($con); ?> ERRORS: From Browser: HTTP Error 500.0 - Internal Server Error C:\php\php-cgi.exe - The FastCGI process exceeded configured activity timeout When i run php -f c:\public_html\index.php from the command line i got: PHP Warning: mysql_connect(): [2002] A connection attempt failed because the co nnected party did not (trying to connect via tcp://localhost:3306) in C:\public _html\index.php on line 10 Warning: mysql_connect(): [2002] A connection attempt failed because the connect ed party did not (trying to connect via tcp://localhost:3306) in C:\public_html \index.php on line 10 PHP Warning: mysql_connect(): A connection attempt failed because the connected party did not properly respond after a period of time, or established connectio n failed because connected host has failed to respond. in C:\public_html\index.php on line 10 Warning: mysql_connect(): A connection attempt failed because the connected part y did not properly respond after a period of time, or established connection fai led because connected host has failed to respond. in C:\public_html\index.php on line 10 Could not connect: A connection attempt failed because the connected party did n ot properly respond after a period of time, or established connection failed bec ause connected host has failed to respond. C:\Users\Kevin>

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• Using nested Master Pages

  - by abatishchev

  Hi. I'm very new to ASP.NET, help me please understand MasterPages conception more. I have Site.master with common header data (css, meta, etc), center form (blank) and footer (copyright info, contact us link, etc). <%@ Master Language="C#" AutoEventWireup="true" CodeFile="Site.master.cs" Inherits="_SiteMaster" %> <!DOCTYPE HTML PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head id="tagHead" runat="server"> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <link rel="stylesheet" href="styles.css" type="text/css" /> </head> <body> <form id="frmMaster" runat="server"> <div> <asp:ContentPlaceHolder ID="holderForm" runat="server"></asp:ContentPlaceHolder> <asp:ContentPlaceHolder ID="holderFooter" runat="server">Some footer here</asp:ContentPlaceHolder> </div> </form> </body> </html> and I want to use second master page for a project into sub directory, which would contains SQL query on Page_Load for logging (it isn't necessary for whole site). <%@ Master Language="C#" AutoEventWireup="true" CodeFile="Project.master.cs" Inherits="_ProjectMaster" MasterPageFile="~/Site.master" %> <asp:Content ContentPlaceHolderID="holderForm" runat="server"> <asp:ContentPlaceHolder ID="holderForm" runat="server" EnableViewState="true"></asp:ContentPlaceHolder> </asp:Content> <asp:Content ContentPlaceHolderID="holderFooter" runat="server"> <asp:ContentPlaceHolder ID="holderFooter" runat="server" EnableViewState="true"></asp:ContentPlaceHolder> </asp:Content> But I have a problem: footer isn't displayed. Where is my mistake? Am I right to use second master page as super class for logging? Project page looks like this: <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" MasterPageFile="~/Project.master" %> <asp:Content ContentPlaceHolderID="holderForm" runat="server"> <p>Hello World!</p> </asp:Content> <asp:Content ContentPlaceHolderID="holderFooter" runat="Server"> Some footer content </asp:Content>

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