Search Results

Search found 20211 results on 809 pages for 'language implementation'.

Page 574/809 | < Previous Page | 570 571 572 573 574 575 576 577 578 579 580 581  | Next Page >

  • check whether fgets would block

    - by lv
    Hi, I was just wondering whether in C is it possible to peek in the input buffer or perform similar trickery to know whether a call to fgets would block at a later time. Java allows to do something like that by calling BufferedReader.ready(), this way I can implement console input something like this: while (on && in.ready()) { line = in.readLine(); /* do something with line */ if (!in.ready()) Thread.sleep(100); } this allows an external thread to gracefully shutdown the input loop by setting on to false; I'd like to perform a similar implementation in C without resorting to non portable tricks, I already know I can make a "timed out fgets" under unix by resorting to signals or (better, even though requering to take care of buffering) reimplement it on top of recv/select, but I'd prefer something that would work on windows too. TIA

    Read the article

  • Double Inner Join generates unexpected error

    - by Itamar Marom
    In my database I have three tables: Users: UserID (Auto Numbering), UserName, UserPassword and a few other unimportant fields. PrivateMessages: MessageID (Auto Numbering), SenderID and a few other fields defining the message content. MessageStatus: MessageID, ReceiverID, MessageWasRead (Boolean) What I need is a query to which I input a user's id and I get all the private messages he has received. In addition, I also need to receive each message's sender UserName. For this I wrote the following query: SELECT Users.*, PrivateMessages.*, MessageStatus.* FROM PrivateMessages INNER JOIN Users ON PrivateMessages.SenderID = Users.UserID INNER JOIN MessageStatus ON PrivateMessages.MessageID = MessageStatus.MessageID WHERE MessageStatus.ReceiverID=[@userid]; But for some reason when I try saving it in my Access database, I get the following error (translated to English by me, since my office is in a different language): Syntax error (missing operator) at expression: "PrivateMessages.SenderID = Users.UserID INNER JOIN MessageStatus ON PrivateMessages.MessageID = MessageStatus.MessageI". Any ideas what could cause this? Thanks.

    Read the article

  • undefined reference to static member variable

    - by Max
    Hi. I have this class that has a static member. it is also a base class for several other classes in my program. Here's its header file: #ifndef YARL_OBJECT_HPP #define YARL_OBJECT_HPP namespace yarlObject { class YarlObject { // Member Variables private: static int nextID; // keeps track of the next ID number to be used int ID; // the identifier for a specific object // Member Functions public: YarlObject(): ID(++nextID) {} virtual ~YarlObject() {} int getID() const {return ID;} }; } #endif and here's its implementation file. #include "YarlObject.hpp" namespace yarlObject { int YarlObject::nextID = 0; } I'm using g++, and it returns three undefined reference to 'yarlObject::YarlObject::nextID linker errors. If I change the ++nextID phrase in the constructor to just nextID, then I only get one error, and if I change it to 1, then it links correctly. I imagine it's something simple, but what's going on?

    Read the article

  • Aren't passwords written in inputbox vulnerable through a stack trace ?

    - by loursonwinny
    Hello, I am not a guru of the stack tracing, at all. I even don't know how to get some. Anyway, I am wondering if entering a password entered in an inputbox is safe. Can't it be retrieved by getting a stack trace ? A password entered that way will be found in many places : Caption property of the TEdit Result of the function which creates the inputbox probably, a variable that stores the Result of the InputBox Command etc... If the answer is "yes, it is a vulnerability", then my world collapses :p. What can be done to avoid that vulnerability hole ? NOTE : The InputBox is an example but it can be with a "homebrewed" login prompt. InputBox is a Delphi command but I haven't tagged the question with the Delphi tag because I suppose that the question concerns any language. Thanks for reading

    Read the article

  • Nonstatic conversion functions; Casting different types, e.g. DirectX vector to OpenGL vector

    - by Markus
    I am currently working on a game "engine" that needs to move values between a 3D engine, a physics engine and a scripting language. Since I need to apply vectors from the physics engine to 3D objects very often and want to be able to control both the 3D, as well as the physics objects through the scripting system, I need a mechanism to convert a vector of one type (e.g. vector3d<float>) to a vector of the other type (e.g. btVector3). Unfortunately I can make no assumptions on how the classes/structs are laid out, so a simple reinterpret_cast probably won't do. So the question is: Is there some sort of 'static'/non-member casting method to achieve basically this: vector3d<float> operator vector3d<float>(btVector3 vector) { // convert and return } btVector3 operator btVector3(vector3d<float> vector) { // convert and return } Right now this won't compile since casting operators need to be member methods. (error C2801: 'operator foo' must be a non-static member)

    Read the article

  • C++0x, How do I expand a tuple into variadic template function arguments?

    - by Gustaf
    Consider the case of a templated function with variadic template arguments: template<typename Tret, typename... T> Tret func(const T&... t); Now, I have a tuple t of values. How do I call func() using the tuple values as arguments? I've read about the bind() function object, with call() function, and also the apply() function in different some now-obsolete documents. The GNU GCC 4.4 implementation seems to have a call() function in the bind() class, but there is very little documentation on the subject. Some people suggest hand-written recursive hacks, but the true value of variadic template arguments is to be able to use them in cases like above. Does anyone have a solution to is, or hint on where to read about it?

    Read the article

  • Interrupting `while loop` with keyboard in Cython

    - by linello
    I want to be able to interrupt a long function with cython, using the usual CTRL+C interrupt command. My C++ long function is repeatedly called inside a while loop from Cython code, but I want to be able, during the loop, to send an "interrupt" and block the while loop. The interrupt also should wait the longFunction() to finish, so that no data are lost or kept in unknown status. This is one of my first implementation, which obviously doesn't work: computed=0; print "Computing long function..." while ( computed==0 ): try: computed = self.thisptr.aLongFunction() except (KeyboardInterrupt, SystemExit): computed=1 print '\n! Received keyboard interrupt.\n' break; (p.s. self.thisptr is the pointer to the current class which implements aLongFunction() )

    Read the article

  • How I Can do web programming with Lisp or Scheme?

    - by Castro
    I usually write web apps in PHP, Ruby or Perl. I am starting the study of Scheme and I want to try some web project with this language. But I can't find what is the best environment for this. I am looking for the following features: A simple way of get the request parameters (something like: get-get #key, get-post #key, get-cookie #key). Mysql access. HTML Form generators, processing, validators, etc. Helpers for filter user input data (something like htmlentities, escape variables for put in queries, etc). FLOSS. And GNU/Linux friendly. So, thanks in advance to all replies.

    Read the article

  • How to communicate with Telecom infrastructure using .NET

    - by Raiford
    I am currently writing some pretty gnarly C#/C++/Cli code to interface with Telecommunication equipement and GSM Mobile Networks for a couple of the major telecom here and abroad. GSM networks primarily use SS7 Signaling using a protocol called TCAP to send messages back and forth to Signaling Points within the network. The laws of Tcp/ip do not apply here :) I am very interested in hearing from others in this space specifically individuals using the .NET framework most likely using C# / C++. I have not come across any .NET libraries or tools to assist in this sort of development. Most of the software in this industry is "C" / Java based, as a result I have written tons of infrastructure .NET code using C# where possible and C++ / CLI to interface with hardware. Is anyone aware of any .NET language tools for this niche industry?

    Read the article

  • Bit conversion operations in PHP

    - by Goro
    Hello, I find myself in need of performing bit-level conversion on variables in PHP. In more detail, I have a bit stream that is read as an integer by hardware, and I need to do some operations on the bits to make it into what its actually supposed to be (a float). I have to do this a few times for different formats, and the functionality I need is Being able to select and move individual bits in a variable Being able to cast statically one type of variable to the other (ie. int to float) I know php natively supports bitwise AND, OR, etc, and shift operations, but I was wondering if: there may already be a library in php that does this sort of thing I would be better off with delegating the calculations to some other language Thanks,

    Read the article

  • How to call a function though Control.BeginInvoke in a signal-slot-like fashion?

    - by Dimitri C.
    I'd like a delegate that calls a function in a different thread when it is invoked. Currently, I'm using the following implementation: delegate void someFunctionDelegate(); //... someFunctionDelegate callBackFunction = someForm.SomeFunction; someForm.Invoke(someFunctionDelegate); However, I'd like a more compact form, combining both the someForm instance and the SomeForm.SomeFunction member function. I'm thinking of something like this: var callBackFunction = new AsynchronousCrossThreadDelegate(someForm, SomeForm.SomeFunction); callBackFunction(); // Should call someForm.BeginInvoke(SomeForm.SomeFunction); Is there a way to do so in C#/.NET? Update I'm looking for a solution that will work for functions with 0 or more parameters.

    Read the article

  • How to create a user customizable database (like Zoho creator) in Rails?

    - by martjno
    I'm learning Rails, and the target of my experiments is to realize something similar to Zoho Creator, Flexlist or Mytaskhelper, i.e. an app where the user can create his own database schema and views. What's the best strategy to pursue this? I saw something about the Entity-Attribute-Value but I'm not sure whether it's the best strategy or if there is some support in Rails for it. If there was any tutorial in Rails about a similar project it would be great. Probably it's not the easiest star for learning a new language and framework, but it would be something I really plan to do since a long time.

    Read the article

  • Are self-described / auto-descriptive services loosely or tightly coupled in a SOA architecture ?

    - by snowflake
    I consider a self-described / auto-descriptive service as a good thing in a SOA architecture, since (almost) everything you know to call the service is present in the service contract (such a WSDL). Sample of a non self-described service for me is Facebook Query Language (FQL http://wiki.developers.facebook.com/index.php/FQL), or any web service exchanging XML flow in a one String parameter for then parsing XML and performing treatments. Last ones seem further more technically decoupled, since technically you can switch implementations without technical impact on the caller, handling compatibility between implementations/versions at a business level. On the other side, having no strong interface (diluted into the service and its version), make the service tightly coupled to the existing implementation (more difficulty to interchange the service and to ensure perfect compatibility). This question is related to http://stackoverflow.com/questions/2503071/how-to-implement-loose-coupling-with-a-soa-architecture So, are self-described / auto-descriptive services loosely or tightly coupled in a SOA architecture ? What are the impacts regarding ESBs ? Any pointer will be appreciated.

    Read the article

  • Trouble setting FIrst view controller which will appear on App Startup

    - by Matte.Car
    I'm setting setting FIrst view controller which will appear on my App Startup. It should appear an UIView first time as a tutorial and, from second time, another standard view. In AppDelegate I wrote this: #import "AppDelegate.h" #import "TabBarController.h" #import "TutorialController.h" @implementation AppDelegate TabBarController * viewControllerStandard; // standard view TutorialController * viewControllerFirst; // tutorial view @synthesize window; - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { if ([@"1" isEqualToString:[[NSUserDefaults standardUserDefaults] objectForKey:@"Startup"]]) { window.rootViewController = viewControllerStandard; } else { window.rootViewController = viewControllerFirst; } [window makeKeyAndVisible]; return YES; } It doesn't return any alert but, launching app, after splashscreen, it appear only a black screen. Without that codes everything works fine. What could be wrong? Thank you!

    Read the article

  • How do you compare music data

    - by Chris
    i want to write an app to rename sort and organize my music library (mp3's, wav's, flac's). I wanted to take a portion of the song, say the first minutes, and compare that to a database and then retrieve the song name and tag information. I have heard that you can do this with last.fm but a look through their api info didn't help. My question is, what is this called so i can google it better? nothing i am trying is helping much. This would be similar to the shazam android app. My prefered language would be java, so i can run it on a few operating systems easier, but that might be subject to change depending on how i can do it. Thanks

    Read the article

  • Fastest Way to generate 1,000,000+ random numbers in python

    - by Sandro
    I am currently writing an app in python that needs to generate large amount of random numbers, FAST. Currently I have a scheme going that uses numpy to generate all of the numbers in a giant batch (about ~500,000 at a time). While this seems to be faster than python's implementation. I still need it to go faster. Any ideas? I'm open to writing it in C and embedding it in the program or doing w/e it takes. Constraints on the random numbers: A Set of numbers 7 numbers that can all have different bounds: eg: [0-X1, 0-X2, 0-X3, 0-X4, 0-X5, 0-X6, 0-X7] Currently I am generating a list of 7 numbers with random values from [0-1) then multiplying by [X1..X7] A Set of 13 numbers that all add up to 1 Currently just generating 13 numbers then dividing by their sum Any ideas? Would pre calculating these numbers and storing them in a file make this faster? Thanks!

    Read the article

  • Developing and deploying games for Windows, Mac (& Linux)

    - by nornagon
    I want to write games that run on all the major platforms. I also want people to be able to play them by downloading a file and double clicking it. That means a single .exe/.app file. I'm happy to use OpenGL directly for graphics. What I don't know how to do is show a window, handle mouse/keyboard input and play sounds in a cross-platform manner. I don't really mind what the underlying language is, as long as it isn't C++ or Java. C#, Ruby or Python would be preferable, in that order :) Please, SO, save me from having to write Flash games!

    Read the article

  • mySQL INSERT INTO SELECT not working

    - by Industrial
    Hi everyone, I am trying to implement the "Closure Table" structure in a php/mySQL webapp from Bill Karwins "SQL Antipatterns" slideshare presentation: http://www.slideshare.net/billkarwin/sql-antipatterns-strike-back The first step is to insert some stuff into my tree (page 73 in slide): Easy to insert a new child of comment #5: INSERT INTO Comments ... (Generates comment #8) INSERT INTO TreePaths (ancestor, descendant) VALUES (8, 8); INSERT INTO TreePaths (ancestor, descendant) SELECT ancestor, 8 FROM TreePaths WHERE descendant = 5; I try to translate all this into Codeigniters active record db-style language, and that's about where I get stuck. I cant understand how the second insert gets it's values. Is there anyone out there who can help me out with this?

    Read the article

  • Why There is a difference between assembly languages like Windows, Linux ?

    - by mcaaltuntas
    I am relatively new to all this low level stuff,assembly language.. and want to learn more detail. Why there is a difference between Linux, Windows Assembly languages? As I understand when I compile a C code Operating system does not really produce pure machine or assembly code, it produces OS dependent binary code.But why ? For example when I use a x86 system, CPU only understands x86 ASM am I right?.So Why we dont write pure x86 assembly code and why there are different assembly variations based on Operating system? If we would write pure ASM or OS produce pure ASM there wouldn't be binary compatilibty issues between Operating systems or Not ? I am really wondering all reasons behind them. Any detailed answer, article, book would be great. Thanks.

    Read the article

  • jQuery is not defined

    - by dole
    Hi there, I have to use an external js file, in which I load the jquery. My js file look like this: document.write('<script language="javascript" type="text/javascript" src="http://code.jquery.com/jquery-1.4.4.min.js"></script>'); (function($) { $(document).ready(function() { alert('it works!!'); }); })(jQuery); On the firefox console I get the "jQuery is not defined" and I think it is because the jQuery library is loaded after the $ function from my js file. Do you have any idea about how can I fix this? If I run the script from the FF console all works fine.

    Read the article

  • Error message in XSLT with C# extension function

    - by iHeartGreek
    Hi! I am received the following error while trying to implement a C# extension function in XSLT. Extension function parameters or return values which have CLR type 'Char[]' are not supported.** code: <xsl:variable name="stringList"> <xsl:value-of select="extension:GetList('AAA BBB CCC', ' ')"/> </xsl:variable> <msxsl:script language="C#" implements-prefix="extension"> <![CDATA[ public string[] GetList(string str, char[] delimiter) { ... ... return str.Split(delimiter, StringSplitOptions.None); } ]]> </msxsl:script> Can someone explain this error message and how to get past it? Thanks!

    Read the article

  • Cocoa multhithreads, locks don't work

    - by Igor
    I have a threadMethod which shows in console robotMotorsStatus every 0.5 sec. But when I try to change robotMotorsStatus in changeRobotStatus method I receive an exception. Where I need to put locks in that program. #import "AppController.h" @implementation AppController extern char *robotMotorsStatus; - (IBAction)runThread:(id)sender { [self performSelectorInBackground:@selector(threadMethod) withObject:nil]; } - (void)threadMethod { char string_to_send[]="QFF001100\r"; //String prepared to the port sending (first inintialization) string_to_send[7] = robotMotorsStatus[0]; string_to_send[8] = robotMotorsStatus[1]; while(1){ [theLock lock]; usleep(500000); NSLog (@"Robot status %s", robotMotorsStatus); [theLock unlock]; } } - (IBAction)changeRobotStatus:(id)sender { robotMotorsStatus[0]='1'; }

    Read the article

  • In Python, are there builtin functions for elementwise boolean operators over boolean lists?

    - by bshanks
    For example, if you have n lists of bools of the same length, then elementwise boolean AND should return another list of that length that has True in those positions where all the input lists have True, and False everywhere else. It's pretty easy to write, i just would prefer to use a builtin if one exists (for the sake of standardization/readability). Here's an implementation of elementwise AND: def eAnd(*args): return [all(tuple) for tuple in zip(*args)] example usage: >>> eAnd([True, False, True, False, True], [True, True, False, False, True], [True, True, False, False, True]) [True, False, False, False, True] thx

    Read the article

  • Why wasn't C# designed with 'const' for variables and methods?

    - by spoulson
    I suspect const was simplified for the C# spec for general language simplicity. Was there a specific reason we can't declare variable references or methods as const like we can with C++? e.g.: const MyObject o = new MyObject(); // Want const cast referenece of MyObject o.SomeMethod(); // Theoretically legal because SomeMethod is const o.ChangeStuff(); // Theoretically illegal because ChangeStuff is not const class MyObject { public int val = 0; public void SomeMethod() const { // Do stuff, but can't mutate due to const declaration. } public void ChangeStuff() { // Code mutates this instance. Can't call with const reference. val++; } }

    Read the article

  • Archiving Database Tables using Java

    - by HonorGod
    My application demands archiving database tables between sybase and db2 and vice-a-versa and within(db2 to db2 and sybase to sybase) using java. I am trying to understand the best strategies around in terms performance, implementation, ease of use and scalability. Here is my current process - source and destination tables with the acceptable parameters (from java) are defined within xml. the application reads the source and destination configurations and execute them sequentially. destination is sometime optional when source is just deleting data from a specific table or when the source is just calling a stored procedure. dataset between source and destination is extremely large (in millions) From top of my head, it looks like I can define dependencies between multiple source and destination combination and have them execute in parallel in multiple treads. But will this improve any performance(i hope it will)? Are there any open-source frameworks for data archiving using java? Any other thoughts on the implements side will be really helpful. Thanks

    Read the article

< Previous Page | 570 571 572 573 574 575 576 577 578 579 580 581  | Next Page >