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  • Can't bind string containing @ char with mysqli_stmt_bind_param

    - by Tirithen
    I have a problem with my database class. I have a method that takes one prepared statement and any number of parameters, binds them to the statement, executes the statement and formats the result into a multidimentional array. Everthing works fine until I try to include an email adress in one of the parameters. The email contains an @ character and that one seems to break everything. When I supply with parameters: $types = "ss" and $parameters = array("[email protected]", "testtest") I get the error: Warning: Parameter 3 to mysqli_stmt_bind_param() expected to be a reference, value given in ...db/Database.class.php on line 63 Here is the method: private function bindAndExecutePreparedStatement(&$statement, $parameters, $types) { if(!empty($parameters)) { call_user_func_array('mysqli_stmt_bind_param', array_merge(array($statement, $types), &$parameters)); /*foreach($parameters as $key => $value) { mysqli_stmt_bind_param($statement, 's', $value); }*/ } $result = array(); $statement->execute() or debugLog("Database error: ".$statement->error); $rows = array(); if($this->stmt_bind_assoc($statement, $row)) { while($statement->fetch()) { $copied_row = array(); foreach($row as $key => $value) { if($value !== null && mb_substr($value, 0, 1, "UTF-8") == NESTED) { // If value has a nested result inside $value = mb_substr($value, 1, mb_strlen($value, "UTF-8") - 1, "UTF-8"); $value = $this->parse_nested_result_value($value); } $copied_row[$ke<y] = $value; } $rows[] = $copied_row; } } // Generate result $result['rows'] = $rows; $result['insert_id'] = $statement->insert_id; $result['affected_rows'] = $statement->affected_rows; $result['error'] = $statement->error; return $result; } I have gotten one suggestion that: the array_merge is casting parameter to string in the merge change it to &$parameters so it remains a reference So I tried that (3rd line of the method), but it did not do any difference. How should I do? Is there a better way to do this without call_user_func_array?

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  • how can I convert String to SecretKey

    - by Alaa
    I want to convert String to secretKey public void generateCode(String keyStr){ KeyGenerator kgen = KeyGenerator.getInstance("AES"); kgen.init(128); // 192 and 256 bits may not be available // Generate the secret key specs. secretKey skey=keyStr; //How can I make the casting here //SecretKey skey = kgen.generateKey(); byte[] raw = skey.getEncoded(); } I try to use BASE64Decoder instead of secretKey, but I face a porblem which is I cannot specify key length. EDIT: I want to call this function from another place static public String encrypt(String message , String key , int keyLength) throws Exception { // Get the KeyGenerator KeyGenerator kgen = KeyGenerator.getInstance("AES"); kgen.init(keyLength); // 192 and 256 bits may not be available // Generate the secret key specs. //decode the BASE64 coded message SecretKey skey = key; //here is the error raw = skey.getEncoded(); SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES"); // Instantiate the cipher Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.ENCRYPT_MODE, skeySpec); System.out.println("msg is" + message + "\n raw is" + raw); byte[] encrypted = cipher.doFinal(message.getBytes()); String cryptedValue = new String(encrypted); System.out.println("encrypted string: " + cryptedValue); return cryptedValue; } Any one can help, i'll be very thankful.

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  • C++ -- Is there an implicit cast here from Fred* to auto_ptr<Fred>?

    - by q0987
    Hello all, I saw the following code, #include <new> #include <memory> using namespace std; class Fred; // Forward declaration typedef auto_ptr<Fred> FredPtr; class Fred { public: static FredPtr create(int i) { return new Fred(i); // Is there an implicit casting here? If not, how can we return // a Fred* with return value as FredPtr? } private: Fred(int i=10) : i_(i) { } Fred(const Fred& x) : i_(x.i_) { } int i_; }; Please see the question listed in function create. Thank you // Updated based on comments Yes, the code cannot pass the VC8.0 error C2664: 'std::auto_ptr<_Ty::auto_ptr(std::auto_ptr<_Ty &) throw()' : cannot convert parameter 1 from 'Fred *' to 'std::auto_ptr<_Ty &' The code was copied from the C++ FAQ 12.15. However, after making the following changes, replace return new Fred(i); with return auto_ptr<Fred>(new Fred(i)); This code can pass the VC8.0 compiler. But I am not sure whether or not this is a correct fix.

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  • C# Inheritence: Choosing what repository based on type of inherited class

    - by Oskar Kjellin
    I have been making a program that downloads information about movies from the internet. I have a base class Title, which represents all titles. Movie, Serie and Episode are inherited from that class. To save them to the database I have 2 services, MovieService and SerieService. They in turn call repositories, but that is not important here. I have a method Save(Title title) which I am not very happy with. I check for what type the title is and then call the correct service. I would like to perhaps write like this: ITitleService service = title.GetService(); title.GetSavedBy(service); So I have an abstract method on Title that returns an ITitleSaver, which will return the correct service for the instance. My question is how should I implement ITitleSaver? If I make it accept Title I will have to cast it to the correct type before calling the correct overload. Which will lead to having to deal with casting once again. What is the best approach to dealing with this? I would like to have the saving logic in the corresponding class.

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  • What is the correct way to handle object which is instance of class in apache.xerces?

    - by Roman
    Preface: I'm working on docx parser for java. docx format is based on xml. When I read document its parts are being unmarshalled (with JAXB). And I get a tree of certain elements based on xml markup. Almost problem: But some elements (which are at very deep xml level) returned not as certain class from docx spec (i.e. CTStyle, CTDrawing, CTInline etc) but as Object. Those objects are indeed instances of xerces classes, e.g. ElementNSImpl. Problem: How should I handle these objects. The simplest approach is: CTGraphicData gData = getGraphicData (); Object obj = gData.getAny().get(0); ElementNSImpl element = (ElementNSImpl)obj; But it doesn't seem to be a good solution. I've never worked with xerces directly. What is the better way to do this casting? (If anyone also give me a tip about right way to iterate through nodes it would be great).

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  • Is it just me? I find LINQ to XML to be sort of cumbersome, compared to XPath.

    - by Cheeso
    I am a C# programmer, so I don't get to take advantage of the cool XML syntax in VB. Dim itemList1 = From item In rss.<rss>.<channel>.<item> _ Where item.<description>.Value.Contains("LINQ") Or _ item.<title>.Value.Contains("LINQ") Using C#, I find XPath to be easier to think about, easier to code, easier to understand, than performing a multi-nested select using LINQ to XML. Look at this syntax, it looks like Greek swearing: var waypoints = from waypoint in gpxDoc.Descendants(gpx + "wpt") select new { Latitude = waypoint.Attribute("lat").Value, Longitude = waypoint.Attribute("lon").Value, Elevation = waypoint.Element(gpx + "ele") != null ? waypoint.Element(gpx + "ele").Value : null, Name = waypoint.Element(gpx + "name") != null ? waypoint.Element(gpx + "name").Value : null, Dt = waypoint.Element(gpx + "cmt") != null ? waypoint.Element(gpx + "cmt").Value : null }; All the casting, the heavy syntax, the possibility for NullPointerExceptions. None of this happens with XPath. I like LINQ in general, and I use it on object collections and databases, but my first go-round with querying XML led me right back to XPath. Is it just me? Am I missing something? EDIT: someone voted to close this as "not a real question". But it is a real question, stated clearly. The question is: Am I misunderstanding something with LINQ to XML?

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  • Passing row from UIPickerView to integer CoreData attribute

    - by Gordon Fontenot
    I'm missing something here, and feeling like an idiot about it. I'm using a UIPickerView in my app, and I need to assign the row number to a 32-bit integer attribute for a Core Data object. To do this, I am using this method: -(void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { object.integerValue = row; } This is giving me a warning: warning: passing argument 1 of 'setIntegerValue:' makes pointer from integer without a cast What am I mixing up here? --EDIT 1-- Ok, so I can get rid of the errors by changing the method to do the following: NSNumber *number = [NSNumber numberWithInteger:row]; object.integerValue = rating; However, I still get a value of 0 for object.integerValue if I use NSLog to print it out. object.integerValue has a max value of 5, so I print out number instead, and then I'm getting a number above 62,000,000. Which doesn't seem right to me, since there are 5 rows. If I NSLog the row variable, I get a number between 0 and 5. So why do I end up with a completely different number after casting the number to NSNumber?

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  • Raycasting with tags problems in unity3d

    - by user1855858
    i need some help here. i have a part of code to search unblocked neighbour with raycast. i need to get raycast that just collide with "WP" tag. both of the iteration shown a right results, so do the dump and the raycast, the raycast does success to collide something, but when i check what the raycast collided with, there is no result shown.... anyone knows whats wrong with this code..?? int flag = 0, flahNeigh = 0; for(flag = 0; flag< wayPoints.WPList.Length; flag++) // iteration to seek neighbour nodes { for (flagNeigh = 0; flagNeigh < wayPoints.WPList.Length; flagNeigh++) { if (wayPoints.WPList[flag].loc != wayPoints.WPList[flagNeigh].loc) // dump its own node location { if (Physics.Raycast(wayPoints.WPList[flag].loc.position, wayPoints.WPList[flagNeigh].loc.position, out hitted)) // raycasting to each node else its self { if (hitted.collider.gameObject.CompareTag("WP")) // check if the ray only collide the node { print(flag + " : " + flagNeigh + " : " + wayPoints.WPList[flagNeigh].loc.position); // debugging to see whether the code works or not (the error comes) } } } } } thanks for the appreciation and answers... sorry if i have a bad english...^^

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  • Issue Querying LDAP DirectoryEntry in ASP.NET

    - by davemackey
    I have users login to my application via Active Directory and then pull from their AD information to garner information about that user like so: Dim ID as FormsIdentity = DirectCast(User.Identity, FormsIdentity) Dim ticket as FormsAuthenticationTicket = ID.Ticket Dim adDirectory as New DirectoryEntry("LDAP://DC=my,DC=domain,DC=com") Dim adTicketID as String = ticket.Name.Substring(0, 5) Session("people_id") = adDirectory.Children.Find("CN=" & adTicketID).Properties("employeeID").Value Session("person_name") = adDirectory.Children.Find("CN=" & adTicketID).Properties("displayName").Value Now, I want to be able to impersonate other users...so that I can "test" the application as them, so I added a textbox and a button to the page and when the button is clicked the text is assigned to a session variable like so: Session("impersonate_user") = TextBox1.Text When the page reloads I check to see if Session("impersonate_user") has a value other than "" and then attempt to query Active Directory using this session variable like so: If CStr(Session("impersonate_user")) <> "" Then Dim adDirectory as New DirectoryEntry(LDAP://DC=my,DC=domain,DC=com") Dim adTicketID as String = CStr(Session("impersonate_user")) Session("people_id") = adDirectory.Children.Find("CN=" & adTicketID).Properties("employeeID").Value Session("person_name")= adDirectory.Children.Find("CN=" & adTicketID).Properties("displayName").Value Else [use the actual ticket.name to get this info.] End If But this doesn't work. Instead, it throws an error on the first Session line stating, "DirectoryServicesCOMException was unhandled by user code There is no such object on the server." Why? I know I'm giving it a valid username! Is something strange happening in the casting of the session? The code is essentially the same between each method except that in one method rather than pulling from ticket.Name I pull from a session variable for the login I'll be looking up with AD.

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  • use startActivityForResult from non-activity

    - by rayman
    Hi, I have MainActivity which is an Activity and other class(which is a simple java class), we`ll call it "SimpleClass". now i want to run from that class the command startActivityForResult. now i though that i could pass that class(SimpleClass), only MainActivity's context, problem is that, u cant run context.startActivityForResult(...); so the only way making SimpleClass to use 'startActivityForResult; is to pass the reference of MainActivity as an Activity variable to the SimpleClass something like that: inside the MainActivity class i create the instance of SimpleClass this way: SimpleClass simpleClass=new SimpleClass(MainActivity.this); now this is how SimpleClass looks like: public Class SimpleClass { Activity myMainActivity; public SimpleClass(Activity mainActivity) { super(); this.myMainActivity=mainActivity; } .... } public void someMethod(...) { myMainActivity.startActivityForResult(...); } now its working, but isnt a proper way of doing this? I`am afraid i could have some memory leaks in the future. thanks. ray.

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  • Is using YIELD a read-only way to return a collection?

    - by Eric
    I'm writing an interface which has a collection property which I want to be read only. I don't want users of the interface to be able to modify the collection. The typical suggestion I've found for creating a read only collection property is to set the type of the property to IEnumerable like this: private List<string> _mylist; public IEnumerable<string> MyList { get { return this._mylist; } } Yet this does not prevent the user from casting the IEnumerable back to a List and modifying it. If I use a Yield keyword instead of returning _mylist directly would this prevent users of my interface from being able to modify the collection. I think so because then I'm only returning the objects one by one, and not the actual collection. private List<string> _mylist; public IEnumerable<string> MyList { get { foreach(string str in this._mylist) { yield return str; } } }

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  • Auto-(un)boxing fail for compound assignment

    - by polygenelubricants
    Thanks to the implicit casting in compound assignments and increment/decrement operators, the following compiles: byte b = 0; ++b; b++; --b; b--; b += b -= b *= b /= b %= b; b <<= b >>= b >>>= b; b |= b &= b ^= b; And thanks to auto-boxing and auto-unboxing, the following also compiles: Integer ii = 0; ++ii; ii++; --ii; ii--; ii += ii -= ii *= ii /= ii %= ii; ii <<= ii >>= ii >>>= ii; ii |= ii &= ii ^= ii; And yet, the last line in the following snippet gives compile-time error: Byte bb = 0; ++bb; bb++; --bb; bb--; // ... okay so far! bb += bb; // DOESN'T COMPILE!!! // "The operator += is undefined for the argument type(s) Byte, byte" Can anyone help me figure out what's going on here? The byte b version compiles just fine, so shouldn't Byte bb just follow suit and do the appropriate boxing and unboxing as necessary to accommodate?

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  • How is conversion of float/double to int handled in printf?

    - by Sandip
    Consider this program int main() { float f = 11.22; double d = 44.55; int i,j; i = f; //cast float to int j = d; //cast double to int printf("i = %d, j = %d, f = %d, d = %d", i,j,f,d); //This prints the following: // i = 11, j = 44, f = -536870912, d = 1076261027 return 0; } Can someone explain why the casting from double/float to int works correctly in the first case, and does not work when done in printf? This program was compiled on gcc-4.1.2 on 32-bit linux machine. EDIT: Zach's answer seems logical, i.e. use of format specifiers to figure out what to pop off the stack. However then consider this follow up question: int main() { char c = 'd'; // sizeof c is 1, however sizeof character literal // 'd' is equal to sizeof(int) in ANSI C printf("lit = %c, lit = %d , c = %c, c = %d", 'd', 'd', c, c); //this prints: lit = d, lit = 100 , c = d, c = 100 //how does printf here pop off the right number of bytes even when //the size represented by format specifiers doesn't actually match //the size of the passed arguments(char(1 byte) & char_literal(4 bytes)) return 0; } How does this work?

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  • Pronunciation of programming structures (particularly in c#)

    - by Andrzej Nosal
    As a non-English speaking person I often have problems pronouncing certain programming structures and abbreviations. I've been watching some video tutorials and listening to podcasts as well, though I couldn't catch them all. My question is what is the common or correct pronunciation of the following code snippets? Generics, like IEnumerable<int> or in a method void Swap<T>(T lhs, T rhs) Collections indexing and indexer access e.g. garage[i], rectangular arrays myArray[2,1] or jagged[1][2][3] Lambda operator =>, e.g. in a where extension method .Where(animal => animal.Color == Color.Brown) or in an anonymous method () => { return false;} Inheritance class Derived : Base (extends?) class SomeClass : IDisposable (implements?) Arithemtic operators += -= *= /= %= ! Are += and -= pronounced the same for events? Collections initializers new int[] { 4, 5, 8, 9, 12, 13, 16, 17 }; Casting MyEnum foo = (MyEnum)(int)yourFloat; (as?) Nullables DateTime? dt = new DateTime?(); I tagged the question with C# as some of them are specific to C# only.

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  • Return an Oracle Associative Array from a function

    - by Paul Johnson
    Does anybody know if it is possible to return an associative array as the result of an Oracle function, if so do you have any examples? I have an Oracle package which contains an associative array declaration as defined below: TYPE EVENTPARAM IS TABLE OF NUMBER INDEX BY BINARY_INTEGER; This is then used in a stored procedure outside the package as follows: v_CompParams areva_interface.eventparam; The intention is to store an associative array of strings in the variable v_CompParams, returned from a Parse function in another package. The definition for which is as follows: PACKAGE STRING_MANIP IS TYPE a_array IS TABLE OF NUMBER INDEX BY BINARY_INTEGER; FUNCTION Parse (v_string VARCHAR2, v_delim VARCHAR2) RETURN a_array; FUNCTION RowCount(colln IN a_array) RETURN NUMBER; END; The code which implements this is: v_CompParams := STRING_MANIP.PARSE(v_CompID,v_Delim); Unfortunately it doesn't work, I get the error 'PLS-00382: expression is of wrong type'. I foolishly assumed, that since a_array derives from the same source Oracle type as the variable v_CompParams, that there would be no problem casting between them. Any help much appreciated. Kind Regards Paul J.

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  • Display subclass data in XCode Expression window

    - by Nick VanderPyle
    I'm debugging an iPhone application I've written using XCode 3.2 and I cannot view the relevant public properties of an object I pull from Core Data. When I watch the object in the Expressions window it only displays the data from the base NSManagedObject. I'd like to see the properties that are on the subclass, not the superclass. If it helps, here's some of the code I'm using. Settings is a subclass of NSManagedObject. I created it using XCode's built-in modeler. Declared like: @interface Settings : NSManagedObject { } @property (nonatomic, retain) NSNumber * hasNews; @property (nonatomic, retain) NSString * logoUrl; @property (nonatomic, retain) NSNumber * hasPaymentGateway; @property (nonatomic, retain) NSString * customerCode; ... In the interface of my controller I have: Settings *settings; I populate settings with: settings = (Settings *)[NSEntityDescription insertNewObjectForEntityForName:@"Settings" inManagedObjectContext:UIAppManagedObjectContext()]; I then set the properties like: settings.hasNews = [NSNumber numberWithBool:TRUE]; I've tried casting settings as (Settings *) in the Expression window but that doesn't help. All I see are the properties to NSManagedObject. I'm using NSLog but would rather not.

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  • Manage multiple UDP calls

    - by rayman
    Hi all, I would like to have an advice for this issue: I am using Jbos 5.1.0, EJB3.0 I have system, which sending requests via UDP'S to remote modems, and suppose to wait for an answer from the target modem. the remote modems support only UDP calls, therefor I o design asynchronous mechanism. (also coz I want to request X modems parallel) this is what I try to do: all calls are retrieved from Data Base, then each call will be added as a message to JMS QUE. let's say i will set X MDB'S on that que, so I can work asynchronous. now each MDB will send UDP request to the IP-address(remote modem) which will be parsed from the que message. so basicly each MDB, which takes a message is sending a udp request to the remote modem and [b]waiting [/b]for an answer from that modem. [u]now here is the BUG:[/u] could happen a scenario where MDB will get an answer, but not from the right modem( which it requested in first place). that bad scenario cause two wrong things: a. the sender which sent the message will wait forever since the message never returned to him(it got accepted by another MDB). b. the MDB which received the message is not the right one, and probablly if it was on a "listener" mode, then it supposed to wait for an answer from diffrent sender.(else it wouldnt get any messages) so ofcourse I can handle everything with a RETRY mechanisem. so both mdb's(the one who got message from the wrong sender, and the one who never got the answer) will try again, to do thire operation with a hope that next time it will success. This is the mechanism, mybe you could tell me if there is any design pattren, or any other effective solution for this problem? Thanks, ray.

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  • How to get the actual address of a pointer in C?

    - by Airjoe
    BACKGROUND: I'm writing a single level cache simulator in C for a homework assignment, and I've been given code that I must work from. In our discussions of the cache, we were told that the way a small cache can hold large addresses is by splitting the large address into the position in the cache and an identifying tag. That is, if you had an 8 slot cache but wanted to store something with address larger than 8, you take the 3 (because 2^3=8) rightmost bits and put the data in that position; so if you had address 22 for example, binary 10110, you would take those 3 rightmost bits 110, which is decimal 5, and put it in slot 5 of the cache. You would also store in this position the tag, which is the remaining bits 10. One function, cache_load, takes a single argument, and integer pointer. So effectively, I'm being given this int* addr which is an actual address and points to some value. In order to store this value in the cache, I need to split the addr. However, the compiler doesn't like when I try to work with the pointer directly. So, for example, I try to get the position by doing: npos=addr%num_slots The compiler gets angry and gives me errors. I tried casting to an int, but this actually got me the value that the pointer was pointing to, not the numerical address itself. Any help is appreciated, thanks!

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  • Why do my raytraced spheres have dark lines when lit with multiple light sources?

    - by Curyous
    I have a simple raytracer that only works back up to the first intersection. The scene looks OK with two different light sources, but when both lights are in the scene, there are dark shadows where the lit area from one ends, even if in the middle of a lit area from the other light source (particularly noticeable on the green ball). The transition from the 'area lit by both light sources' to the 'area lit by just one light source' seems to be slightly darker than the 'area lit by just one light source'. The code where I'm adding the lighting effects is: // trace lights for ( int l=0; l<primitives.count; l++) { Primitive* p = [primitives objectAtIndex:l]; if (p.light) { Sphere * lightSource = (Sphere *)p; // calculate diffuse shading Vector3 *light = [[Vector3 alloc] init]; light.x = lightSource.centre.x - intersectionPoint.x; light.y = lightSource.centre.y - intersectionPoint.y; light.z = lightSource.centre.z - intersectionPoint.z; [light normalize]; Vector3 * normal = [[primitiveThatWasHit getNormalAt:intersectionPoint] retain]; if (primitiveThatWasHit.material.diffuse > 0) { float illumination = DOT(normal, light); if (illumination > 0) { float diff = illumination * primitiveThatWasHit.material.diffuse; // add diffuse component to ray color colour.red += diff * primitiveThatWasHit.material.colour.red * lightSource.material.colour.red; colour.blue += diff * primitiveThatWasHit.material.colour.blue * lightSource.material.colour.blue; colour.green += diff * primitiveThatWasHit.material.colour.green * lightSource.material.colour.green; } } [normal release]; [light release]; } } How can I make it look right?

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  • Destroy process-less console windows left by Visual Studio debug sessions

    - by jon hanson
    A known bug with security update KB978037 can occur with Visual Studio 2003 (and 2008) where sometimes if you restart a debugging session on a console app then the console window doesn't get closed even though the owner process no longer exists. The problem is discussed further here: http://stackoverflow.com/questions/2402875/visual-studio-debug-console-sometimes-stays-open-and-is-impossible-to-close These zombie windows then can not be closed via the Taskbar or via the TaskManager, and typically require a power off/on to get rid of them. Over the period of even a single day you can accumulate quite a few of them, which clog up your TaskBar and are generally annoying. I thought I would knock up a simple C++ Win32 utility to attempt to call DestroyWindow() on these windows by passing the windows handle as a cmd-line argument and converting it to a HWND. I'm converting the handle from a string by parsing it as a DWORD then casting the DWORD to a HWND. This appears to be working as if I call GetWindowInfo() on the handle it succeeds. However calling DestroyWindow() on the handle fails with error 5 (access denied), presumably because the caller process (i.e. my app) doesn't own the window in question. Any ideas as to how I might get rid of the zombie windows, either via the above approach or any other alternative short of rebooting? I'm in a corporate environment so installing/uninstalling updates/service-packs etc isn't an option.

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  • gcc, strict-aliasing, and horror stories

    - by Joseph Quinsey
    In http://stackoverflow.com/questions/2906365/gcc-strict-aliasing-and-casting-through-a-union I asked whether anyone had encountered problems with union punning through pointers. So far, the answer seems to be No. This question is broader: do you have any horror stories about gcc and strict-aliasing? Background: Quoting from AndreyT's answer in http://stackoverflow.com/questions/2771023/c99-strict-aliasing-rules-in-c-gcc/2771041#2771041: "Strict aliasing rules are rooted in parts of the standard that were present in C and C++ since the beginning of [standardized] times. The clause that prohibits accessing object of one type through a lvalue of another type is present in C89/90 (6.3) as well as in C++98 (3.10/15). ... It is just that not all compilers wanted (or dared) to enforce it or rely on it." Well, gcc is now daring to do so, with its -fstrict-aliasing switch. And this has caused some problems. See, for example, the excellent article http://davmac.wordpress.com/2009/10/ about a Mysql bug, and the equally excellent discussion in http://cellperformance.beyond3d.com/articles/2006/06/understanding-strict-aliasing.html. Some other less-relevant links: http://stackoverflow.com/questions/1225741/performance-impact-of-fno-strict-aliasing http://stackoverflow.com/questions/754929/strict-aliasing http://stackoverflow.com/questions/262379/when-is-char-safe-for-strict-pointer-aliasing http://stackoverflow.com/questions/725138/how-to-detect-strict-aliasing-at-compile-time So to repeat, do you have a horror story of your own? Problems not indicated by -Wstrict-aliasing would, of course, be preferred. And other C compilers are also welcome.

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  • The fastest way to iterate through a collection of objects

    - by Trev
    Hello all, First to give you some background: I have some research code which performs a Monte Carlo simulation, essential what happens is I iterate through a collection of objects, compute a number of vectors from their surface then for each vector I iterate through the collection of objects again to see if the vector hits another object (similar to ray tracing). The pseudo code would look something like this for each object { for a number of vectors { do some computations for each object { check if vector intersects } } } As the number of objects can be quite large and the amount of rays is even larger I thought it would be wise to optimise how I iterate through the collection of objects. I created some test code which tests arrays, lists and vectors and for my first test cases found that vectors iterators were around twice as fast as arrays however when I implemented a vector in my code in was somewhat slower than the array I was using before. So I went back to the test code and increased the complexity of the object function each loop was calling (a dummy function equivalent to 'check if vector intersects') and I found that when the complexity of the function increases the execution time gap between arrays and vectors reduces until eventually the array was quicker. Does anyone know why this occurs? It seems strange that execution time inside the loop should effect the outer loop run time.

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  • Having trouble creating vectors of System::String^

    - by Justen
    So I have a regex expression to parse certain parts of a file name. I'm trying to store each part in its own vector until I use it later, but it won't let me. One error I get when I try making a vector of System::String^ is that error C3698: 'System::String ^' : cannot use this type as argument of 'new' Then, when I try just making a vector of std::string, it can't implicitly convert to type System::String^, and casting won't work either. void parseData() { System::String^ pattern = "(\\D+)(\\d+)(\\w{1})(\\d+)\\.(\\D{3})"; std::vector < System::String^ > x, y, filename, separator; Regex re( pattern ); for ( int i = 0; i < openFileDialog1->FileNames->Length; i++ ) { Match^ m = re.Match( openFileDialog1->FileNames[i] ); filename.push_back( m->Groups[0]->Value );/* x.push_back( m->Groups[1]->Value ); separator.push_back( m->Groups[2]->Value ); y.push_back( m->Groups[3]->Value );*/ } }

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  • Conversion failed when converting the varchar value to int

    - by onedaywhen
    Microsoft SQL Server 2008 (SP1), getting an unexpected 'Conversion failed' error. Not quite sure how to describe this problem, so below is a simple example. The CTE extracts the numeric portion of certain IDs using a search condition to ensure a numeric portion actually exists. The CTE is then used to find the lowest unused sequence number (kind of): CREATE TABLE IDs (ID CHAR(3) NOT NULL UNIQUE); INSERT INTO IDs (ID) VALUES ('A01'), ('A02'), ('A04'), ('ERR'); WITH ValidIDs (ID, seq) AS ( SELECT ID, CAST(RIGHT(ID, 2) AS INTEGER) FROM IDs WHERE ID LIKE 'A[0-9][0-9]' ) SELECT MIN(V1.seq) + 1 AS next_seq FROM ValidIDs AS V1 WHERE NOT EXISTS ( SELECT * FROM ValidIDs AS V2 WHERE V2.seq = V1.seq + 1 ); The error is, 'Conversion failed when converting the varchar value 'RR' to data type int.' I can't understand why the value ID = 'ERR' should be being considered for conversion because the predicate ID LIKE 'A[0-9][0-9]' should have removed the invalid row from the resultset. When the base table is substituted with an equivalent CTE the problem goes away i.e. WITH IDs (ID) AS ( SELECT 'A01' UNION ALL SELECT 'A02' UNION ALL SELECT 'A04' UNION ALL SELECT 'ERR' ), ValidIDs (ID, seq) AS ( SELECT ID, CAST(RIGHT(ID, 2) AS INTEGER) FROM IDs WHERE ID LIKE 'A[0-9][0-9]' ) SELECT MIN(V1.seq) + 1 AS next_seq FROM ValidIDs AS V1 WHERE NOT EXISTS ( SELECT * FROM ValidIDs AS V2 WHERE V2.seq = V1.seq + 1 ); Why would a base table cause this error? Is this a known issue? UPDATE @sgmoore: no, doing the filtering in one CTE and the casting in another CTE still results in the same error e.g. WITH FilteredIDs (ID) AS ( SELECT ID FROM IDs WHERE ID LIKE 'A[0-9][0-9]' ), ValidIDs (ID, seq) AS ( SELECT ID, CAST(RIGHT(ID, 2) AS INTEGER) FROM FilteredIDs ) SELECT MIN(V1.seq) + 1 AS next_seq FROM ValidIDs AS V1 WHERE NOT EXISTS ( SELECT * FROM ValidIDs AS V2 WHERE V2.seq = V1.seq + 1 );

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  • Return value from Object match

    - by Hito_kun
    I'm, by no means, JS fluent, so forgive me if im asking for some really basic stuff, but I've not being able to find a proper answer to my question. Im writting my first Node.js (plus Extra Framework and Socket.io) app and Im having some fun setting up the server side of a FB-like messenger (surprise!!!). So, let's say I have this data structure to store online users(This is a JSON Array, but I'm not sure it is the best way to do it or should I go with Javascript Objects): [ { "site": 45, "users": [ { "idUser": 5, "idSocket": "qwe87r7w8qwe", "name": "Carlos Ray Norris" }, { "idUser": 6, "idSocket": "v8d9d0fgfs7d", "name": "John Connor" } ] }, { "site": 48, "users": [ { "idUser": 22, "idSocket": "qwe87r7w8qwe", "name": "David Bowie" }, { "idUser": 23, "idSocket": "v8d9d0fgfs7d", "name": "Barack H. Obama" } ] } ] What I want to do is to search in the array for x value given y. In this case, retrieving the idSocket knowing the idUser WITHOUT having to run through the array values. So I have basically 2 questions: first, what would be the proper way to store users online? and secondly, how to find values matching with the values I already know (find the idSocket that has a given idUser). I would like a pure JS approach(or using some of the tools given by Node, Socket.io or Express), but if that's not possible then I can look for some JQuery.

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