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  • iPhone - Using sql database - insert statement failing

    - by Satyam svv
    Hi, I'm using sqlite database in my iphone app. I've a table which has 3 integer columns. I'm using following code to write to that database table. -(BOOL)insertTestResult { NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); NSString* documentsDirectory = [paths objectAtIndex:0]; NSString* dataBasePath = [documentsDirectory stringByAppendingPathComponent:@"test21.sqlite3"]; BOOL success = NO; sqlite3* database = 0; if(sqlite3_open([dataBasePath UTF8String], &database) == SQLITE_OK) { BOOL res = (insertResultStatement == nil) ? createStatement(insertResult, &insertResultStatement, database) : YES; if(res) { int i = 1; sqlite3_bind_int(insertResultStatement, 0, i); sqlite3_bind_int(insertResultStatement, 1, i); sqlite3_bind_int(insertResultStatement, 2, i); int err = sqlite3_step(insertResultStatement); if(SQLITE_ERROR == err) { NSAssert1(0, @"Error while inserting Result. '%s'", sqlite3_errmsg(database)); success = NO; } else { success = YES; } sqlite3_finalize(insertResultStatement); insertResultStatement = nil; } } sqlite3_close(database); return success;} The command sqlite3_step is always giving err as 19. I'm not able to understand where's the issue. Tables are created using following queries: CREATE TABLE [Patient] (PID integer NOT NULL PRIMARY KEY AUTOINCREMENT UNIQUE,PFirstName text NOT NULL,PLastName text,PSex text NOT NULL,PDOB text NOT NULL,PEducation text NOT NULL,PHandedness text,PType text) CREATE TABLE PatientResult(PID INTEGER,PFreeScore INTEGER NOT NULL,PForcedScore INTEGER NOT NULL,FOREIGN KEY (PID) REFERENCES Patient(PID)) I've only one entry in Patient table with PID = 1 BOOL createStatement(const char* query, sqlite3_stmt** stmt, sqlite3* database){ BOOL res = (sqlite3_prepare_v2(database, query, -1, stmt, NULL) == SQLITE_OK); if(!res) NSLog( @"Error while creating %s => '%s'", query, sqlite3_errmsg(database)); return res;}

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  • Why does this code leak? (simple codesnippet)

    - by Ela782
    Visual Studio shows me several leaks (a few hundred lines), in total more than a few MB. I traced it down to the following "helloWorld example". The leak disappears if I comment out the H5::DataSet.getSpace() line. #include "stdafx.h" #include <iostream> #include "cpp/H5Cpp.h" int main(int argc, char *argv[]) { _CrtSetDbgFlag ( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF ); // dump leaks at return H5::H5File myfile; try { myfile = H5::H5File("C:\\Users\\yyy\\myfile.h5", H5F_ACC_RDONLY); } catch (H5::Exception& e) { std::string msg( std::string( "Could not open HDF5 file.\n" ) + e.getCDetailMsg() ); throw msg; } H5::Group myGroup = myfile.openGroup("/so/me/group"); H5::DataSet myDS = myGroup.openDataSet("./myfloatvec"); hsize_t dims[1]; //myDS.getSpace().getSimpleExtentDims(dims, NULL); // <-- here's the leak H5::DataSpace dsp = myDS.getSpace(); // The H5::DataSpace seems to leak dsp.getSimpleExtentDims(dims, NULL); //dsp.close(); // <-- doesn't help either std::cout << "Dims: " << dims[0] << std::endl; // <-- Works as expected return 0; } Any help would be appreciated. I've been on this for hours, I hate unclean code...

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  • How can several different datatypes be saved in one table

    - by poseidon
    This is my situation: I am constructing an ad-like application in Django and Mysql. I am using a flexible-ad approach where we have: a table with ad categories (several categories such as home, furniture, cars, etc.) id_category name a table with details for the ad categories (home: area, squared meters. car: seats, color.) id_detail id_category (the categ the detail describes) name type (boolean, char, int, long, etc.) the ad table (i am selling a house. i am selling a car.) id_ad id_category text date a table where i plan to consolidate the details of the ads (home: A-area, 500 sq-meters. car: 5 seats, red.) id_detail_ad id_ad id_detail value Is this possible? Can I have a table of details for all the ads, even if details include numbers, texts, booleans, etc? Or would I have to save them all as text and then interpret them via code accordingly? Please express your opinions. Thank you.

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  • Getting functions of inherited functions to be called

    - by wrongusername
    Let's say I have a base class Animal from which a class Cow inherits, and a Barn class containing an Animal vector, and let's say the Animal class has a virtual function scream(), which Cow overrides. With the following code: Animal.h #ifndef _ANIMAL_H #define _ANIMAL_H #include <iostream> using namespace std; class Animal { public: Animal() {}; virtual void scream() {cout << "aaaAAAAAAAAAAGHHHHHHHHHH!!! ahhh..." << endl;} }; #endif /* _ANIMAL_H */ Cow.h #ifndef _COW_H #define _COW_H #include "Animal.h" class Cow: public Animal { public: Cow() {} void scream() {cout << "MOOooooOOOOOOOO!!!" << endl;} }; #endif /* _COW_H */ Barn.h #ifndef _BARN_H #define _BARN_H #include "Animal.h" #include <vector> class Barn { std::vector<Animal> animals; public: Barn() {} void insertAnimal(Animal animal) {animals.push_back(animal);} void tortureAnimals() { for(int a = 0; a < animals.size(); a++) animals[a].scream(); } }; #endif /* _BARN_H */ and finally main.cpp #include <stdlib.h> #include "Barn.h" #include "Cow.h" #include "Chicken.h" /* * */ int main(int argc, char** argv) { Barn barn; barn.insertAnimal(Cow()); barn.tortureAnimals(); return (EXIT_SUCCESS); } I get this output: aaaAAAAAAAAAAGHHHHHHHHHH!!! ahhh... How should I code this to get MOOooooOOOOOOOO!!! (and whatever other classes inheriting Animal wants scream() to be) instead?

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  • useer degined Copy ctor, and copy-ctors further down the chain - compiler bug ? programers brainbug

    - by J.Colmsee
    Hi. i have a little problem, and I am not sure if it's a compiler bug, or stupidity on my side. I have this struct : struct BulletFXData { int time_next_fx_counter; int next_fx_steps; Particle particles[2];//this is the interesting one ParticleManager::ParticleId particle_id[2]; }; The member "Particle particles[2]" has a self-made kind of smart-ptr in it (resource-counted texture-class). this smart-pointer has a default constructor, that initializes to the ptr to 0 (but that is not important) I also have another struct, containing the BulletFXData struct : struct BulletFX { BulletFXData data; BulletFXRenderFunPtr render_fun_ptr; BulletFXUpdateFunPtr update_fun_ptr; BulletFXExplosionFunPtr explode_fun_ptr; BulletFXLifetimeOverFunPtr lifetime_over_fun_ptr; BulletFX( BulletFXData data, BulletFXRenderFunPtr render_fun_ptr, BulletFXUpdateFunPtr update_fun_ptr, BulletFXExplosionFunPtr explode_fun_ptr, BulletFXLifetimeOverFunPtr lifetime_over_fun_ptr) :data(data), render_fun_ptr(render_fun_ptr), update_fun_ptr(update_fun_ptr), explode_fun_ptr(explode_fun_ptr), lifetime_over_fun_ptr(lifetime_over_fun_ptr) { } /* //USER DEFINED copy-ctor. if it's defined things go crazy BulletFX(const BulletFX& rhs) :data(data),//this line of code seems to do a plain memory-copy without calling the right ctors render_fun_ptr(render_fun_ptr), update_fun_ptr(update_fun_ptr), explode_fun_ptr(explode_fun_ptr), lifetime_over_fun_ptr(lifetime_over_fun_ptr) { } */ }; If i use the user-defined copy-ctor my smart-pointer class goes crazy, and it seems that calling the CopyCtor / assignment operator aren't called as they should. So - does this all make sense ? it seems as if my own copy-ctor of struct BulletFX should do exactly what the compiler-generated would, but it seems to forget to call the right constructors down the chain. compiler bug ? me being stupid ? Sorry about the big code, some small example could have illustrated too. but often you guys ask for the real code, so well - here it is :D

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  • Using Relative Paths to Load Resources in Cocoa/C++

    - by moka
    I am currently working directly with Cocoa for the first time to built a screen saver. Now I came across a problem when trying to load resources from within the .saver bundle. I basically have a small C++ wrapper class to load .exr files using freeImage. This works as long as I use absoulte paths, but that's not very useful, is it? So, basically, I tried everything: putting the .exr file at the level of the .saver bundle itself, inside the bundles Resources folder, and so on. Then I simply tried to load the .exr like this, but without success: particleTex = [self loadExrTexture:@"ball.exr"]; I also tried making it go to the .saver bundles location like this: particleTex = [self loadExrTexture:@"../../../ball.exr"]; ...to maybe load the .exr from that location, but without success. I then came across this: NSString * path = [[NSBundle mainBundle] pathForResource:@"ball" ofType:@"exr"]; const char * pChar = [path UTF8String]; ...which seems to be a common way to find resources in Cocoa, but for some reason it's empty in my case. Any ideas about that? I really tried out anything that came to my mind without success so I would be glad about some input!

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  • Scanning, Checking, Converting, Copying values ... How to ? -- C --

    - by ZaZu
    Hi there, Its been a while now and im still trying to get a certain code to work. I asked some question about different commands etc. before, but now I hope this is the final one (combining all questions in one code). I basically want to : *Scan an input (should be character ? ) *Check if its a number *If not, return error *Convert that character into a float number *Copy the value to another variable ( I called it imp here) Here is what I came up with : #include<stdio.h> #include<stdlib.h> #include<ctype.h> main(){ int digits; float imp=0; int alpha; do{ printf("Enter input\n\n"); scanf("\n%c",&alpha); digits=isdigit(alpha); if(digits==0){ printf("error\n\n"); } imp=atof(alpha); }while(digits==0); } The problem is this code does not work at all ... It gives me that atof must be of a const char and whenever I try changing it around, it just keeps failing. I am frustrated and forced to ask here, because I believe I have tried alot and I keep failing, but I wont be relieved until I get it to work xD So I really need your help guys. Please tell me why isnt this code working, what am I doing wrong ? I am still learning C and really appreciate your help :)

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  • SQLite DB open time really long Problem

    - by sxingfeng
    I am using sqlite in c++ windows, And I have a db size about 60M, When I open the sqlite db, It takes about 13 second. sqlite3* mpDB; nRet = sqlite3_open16(szFile, &mpDB); And if I closed my application and reopen it again. It takse only less then 1 second. First, I thought It is because of disk cache. So I preload the 60M db file before sqlite open, and read the file using CFile, However, after preloading, the first time is still very slow. BOOL CQFilePro::PreLoad(const CString& strPath) { boost::shared_array<BYTE> temp = boost::shared_array<BYTE>(new BYTE[PRE_LOAD_BUFFER_LENGTH]); int nReadLength; try { CFile file; if (file.Open(strPath, CFile::modeRead) == FALSE) { return FALSE; } do { nReadLength = file.Read(temp.get(), PRE_LOAD_BUFFER_LENGTH); } while (nReadLength == PRE_LOAD_BUFFER_LENGTH); file.Close(); } catch(...) { } return TRUE; } My question is what is the difference between first open and second open. How can I accelerate the sqlite open-process.

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  • Need help profiling .NET caching extension method.

    - by rockinthesixstring
    I've got the following extension Public Module CacheExtensions Sub New() End Sub Private sync As New Object() Public Const DefaultCacheExpiration As Integer = 1200 ''# 20 minutes <Extension()> Public Function GetOrStore(Of T)(ByVal cache As Cache, ByVal key As String, ByVal generator As Func(Of T)) As T Return cache.GetOrStore(key, If(generator IsNot Nothing, generator(), Nothing), DefaultCacheExpiration) End Function <Extension()> Public Function GetOrStore(Of T)(ByVal cache As Cache, ByVal key As String, ByVal generator As Func(Of T), ByVal expireInSeconds As Double) As T Return cache.GetOrStore(key, If(generator IsNot Nothing, generator(), Nothing), expireInSeconds) End Function <Extension()> Public Function GetOrStore(Of T)(ByVal cache As Cache, ByVal key As String, ByVal obj As T) As T Return cache.GetOrStore(key, obj, DefaultCacheExpiration) End Function <Extension()> Public Function GetOrStore(Of T)(ByVal cache As Cache, ByVal key As String, ByVal obj As T, ByVal expireInSeconds As Double) As T Dim result = cache(key) If result Is Nothing Then SyncLock sync If result Is Nothing Then result = If(obj IsNot Nothing, obj, Nothing) cache.Insert(key, result, Nothing, DateTime.Now.AddSeconds(expireInSeconds), cache.NoSlidingExpiration) End If End SyncLock End If Return DirectCast(result, T) End Function End Module From here, I'm using the extension is a TagService to get a list of tags Public Function GetTagNames() As List(Of String) Implements Domain.ITagService.GetTags ''# We're not using a dynamic Cache key because the list of TagNames ''# will persist across all users in all regions. Return HttpRuntime.Cache.GetOrStore(Of List(Of String))("TagNamesOnly", Function() _TagRepository.Read().Select(Function(t) t.Name).OrderBy(Function(t) t).ToList()) End Function All of this is pretty much straight forward except when I put a breakpoint on _TagRepository.Read(). The problem is that it is getting called on every request, when I thought that it is only to be called when Result Is Nothing Am I missing something here?

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  • Modifying bundled properties from visitor

    - by ravenspoint
    How should I modify the bundled properties of a vertex from inside a visitor? I would like to use the simple method of sub-scripting the graph, but the graph parameter passed into the visitor is const, so compiler disallows changes. I can store a reference to the graph in the visitor, but this seems weird. /** A visitor which identifies vertices as leafs or trees */ class bfs_vis_leaf_finder:public default_bfs_visitor { public: /** Constructor @param[in] total reference to int variable to store total number of leaves @param[in] g reference to graph ( used to modify bundled properties ) */ bfs_vis_leaf_finder( int& total, graph_t& g ) : myTotal( total ), myGraph( g ) { myTotal = 0; } /** Called when the search finds a new vertex If the vertex has no children, it is a leaf and the total leaf count is incremented */ template <typename Vertex, typename Graph> void discover_vertex( Vertex u, Graph& g) { if( out_edges( u, g ).first == out_edges( u, g ).second ) { myTotal++; //g[u].myLevel = s3d::cV::leaf; myGraph[u].myLevel = s3d::cV::leaf; } else { //g[u].myLevel = s3d::cV::tree; myGraph[u].myLevel = s3d::cV::tree; } } int& myTotal; graph_t& myGraph; };

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  • IE7 & IE8 error executing function with ajax

    - by Yahreen
    I am loading an ajax page which executes an HTML5 video player script. The function for the Flash fallback is html5media(); : //Load 1st Case Study $("#splash").live('click', function (e) { $(this).fadeOut('slow', function () { $('#case-studies').load('case-study-1.html', function() { html5media(); //initiate Flash fallback }).fadeIn(); }); e.preventDefault(); }); This initial page load works fine in IE7 & IE8. The problem is once this page is loaded, there are links to 4 more videos which are loaded in again using ajax. I use this function: //Switcher function csClients(url, client) { $("#case-studies").fadeOut('slow', function() { $('#case-studies').load(url, function () { html5media(); //initiate Flash fallback }).fadeIn(); }); } //Page Loader $("#cs-client-list li.client1 a").live('click', function(e) { csClients('case-study-1.html', 'client1'); e.preventDefault(); }); Originally I was using return false; but none of the sub-page Flash videos would load in IE7. When I switched to preventDefault, the videos loaded in IE7 but still not in IE8. I also get a weird error in both IE7 & IE8 with no helpful feedback: Error on Page: Unspecified error. / (Line 49) Code: 0 (Char 5) URI: http://www.mysite.com This is line 49 in my index page: <section id="case-studies" class="main-section"> I have a feeling it has to do with calling html5media(); too many times? At a loss...

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  • C++: Maybe you know this fitfall?

    - by Martijn Courteaux
    Hi, I'm developing a game. I have a header GameSystem (just methods like the game loop, no class) with two variables: int mouseX and int mouseY. These are updated in my game loop. Now I want to access them from Game.cpp file (a class built by a header-file and the source-file). So, I #include "GameSystem.h" in Game.h. After doing this I get a lot of compile errors. When I remove the include he says of course: Game.cpp:33: error: ‘mouseX’ was not declared in this scope Game.cpp:34: error: ‘mouseY’ was not declared in this scope Where I want to access mouseX and mouseY. All my .h files have Header Guards, generated by Eclipse. I'm using SDL and if I remove the lines that wants to access the variables, everything compiles and run perfectly (*). I hope you can help me... This is the error-log when I #include "GameSystem.h" (All the code he is refering to works, like explained by the (*)): In file included from ../trunk/source/domein/Game.h:14, from ../trunk/source/domein/Game.cpp:8: ../trunk/source/domein/GameSystem.h:30: error: expected constructor, destructor, or type conversion before ‘*’ token ../trunk/source/domein/GameSystem.h:46: error: variable or field ‘InitGame’ declared void ../trunk/source/domein/GameSystem.h:46: error: ‘Game’ was not declared in this scope ../trunk/source/domein/GameSystem.h:46: error: ‘g’ was not declared in this scope ../trunk/source/domein/GameSystem.h:46: error: expected primary-expression before ‘char’ ../trunk/source/domein/GameSystem.h:46: error: expected primary-expression before ‘bool’ ../trunk/source/domein/FPS.h:46: warning: ‘void FPS_SleepMilliseconds(int)’ defined but not used This is the code which try to access the two variables: SDL_Rect pointer; pointer.x = mouseX; pointer.y = mouseY; pointer.w = 3; pointer.h = 3; SDL_FillRect(buffer, &pointer, 0xFF0000);

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  • Strange Access Denied warning when running the simplest C++ program.

    - by DaveJohnston
    I am just starting to learn C++ (coming from a Java background) and I have come across something that I can't explain. I am working through the C++ Primer book and doing the exercises. Every time I get to a new exercise I create a new .cpp file and set it up with the main method (and any includes I think I will need) e.g.: #include <list> #include <vector> int main(int argc, char **args) { } and just to make sure I go to the command prompt and compile and run: g++ whatever.cpp a.exe Normally this works just fine and I start working on the exercise, but I just did it and got a strange error. It compiles fine, but when I run it it says Access Denied and AVG pops up telling me that a threat has been detected 'Trojan Horse Generic 17.CKZT'. I tried compiling again using the Microsoft Compiler (cl.exe) and it runs fines. So I went back, and added: #include <iostream> compiled using g++ and ran. This time it worked fine. So can anyone tell me why AVG would report an empty main method as a trojan horse but if the iostream header is included it doesn't?

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  • How do you use boost iterators

    - by Neil G
    It worked, and then I added the typedefs so that I could have a const_sparse_iterator as well. Now, when I compile this and try to use sparse_iterator, it says: /Users/neilrg/nn/src/./core/sparse_vector.h:331: error: invalid use of incomplete type 'struct sparse_vector<A>::sparse_iterator' Here's the code. More code here. tempalte<typename T> class sparse_vector { // There is more code at my previous question, but this might be enough...? private: template<typename base_type> class sparse_iterator_private : public boost::iterator_adaptor< sparse_iterator_private<base_type> // Derived , base_type // Base , value_type // Value , boost::random_access_traversal_tag // CategoryOrTraversal > { private: struct enabler {}; // a private type avoids misuse public: sparse_iterator_private() : sparse_iterator_private<base_type>::iterator_adaptor_(0) {} explicit sparse_iterator_private(typename array_type::iterator&& p) : sparse_iterator_private<base_type>::iterator_adaptor_(p) {} private: friend class boost::iterator_core_access; reference dereference() const { return this->base()->value; } }; public: typedef sparse_iterator_private<typename array_type::iterator> sparse_iterator; typedef sparse_iterator_private<typename array_type::const_iterator> const_sparse_iterator; };

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  • C Programming. How to deep copy a struct?

    - by user69514
    I have the following two structs where "child struct" has a "rusage struct" as an element. Then I create two structs of type "child" let's call them childA and childB How do I copy just the rusage struct from childA to childB? typedef struct{ int numb; char *name; pid_t pid; long userT; long systemT; struct rusage usage; }child; typedef struct{ struct timeval ru_utime; /* user time used */ struct timeval ru_stime; /* system time used */ long ru_maxrss; /* maximum resident set size */ long ru_ixrss; /* integral shared memory size */ long ru_idrss; /* integral unshared data size */ long ru_isrss; /* integral unshared stack size */ long ru_minflt; /* page reclaims */ long ru_majflt; /* page faults */ long ru_nswap; /* swaps */ long ru_inblock; /* block input operations */ long ru_oublock; /* block output operations */ long ru_msgsnd; /* messages sent */ long ru_msgrcv; /* messages received */ long ru_nsignals; /* signals received */ long ru_nvcsw; /* voluntary context switches */ long ru_nivcsw; /* involuntary context switches */ }rusage; I did the following, but I guess it copies the memory location, because if I changed the value of usage in childA, it also changes in childB. memcpy(&childA,&childB, sizeof(rusage)); I know that gives childB all the values from childA. I have already taken care of the others fields in childB, I just need to be able to copy the rusage struct called usage that resides in the "child" struct.

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  • OSX launchctl programmatically as root

    - by Lukas1
    I'm trying to start samba service using launchctl from OSX app as root, but I get error status -60031. I can run without problems the command in Terminal: sudo launchctl load -F /System/Library/LaunchDaemons/com.apple.AppleFileServer.plist` In the objective-c code, I'm using (I know it's deprecated, but that really shouldn't be the issue here) AuthorizationExecuteWithPrivileges method. Here's the code: NSString *command = @"launchctl"; // Conversion of NSArray args to char** args here (not relevant part of the code) OSStatus authStatus = AuthorizationCreate(NULL, kAuthorizationEmptyEnvironment, kAuthorizationFlagDefaults, &_authRef); if (authStatus != errAuthorizationSuccess) { NSLog(@"Failed to create application authorization: %d", (int)authStatus); return; } FILE* pipe = NULL; AuthorizationFlags flags = kAuthorizationFlagDefaults; AuthorizationItem right = {kAuthorizationRightExecute, 0, NULL, 0}; AuthorizationRights rights = {1, &right}; // Call AuthorizationCopyRights to determine or extend the allowable rights. OSStatus stat = AuthorizationCopyRights(_authRef, &rights, NULL, flags, NULL); if (stat != errAuthorizationSuccess) { NSLog(@"Copy Rights Unsuccessful: %d", (int)stat); return; } OSStatus status = AuthorizationExecuteWithPrivileges(_authRef, command.UTF8String, flags, args, &pipe); if (status != errAuthorizationSuccess) { NSLog(@"Error executing command %@ with status %d", command, status); } else { // some other stuff } I have also tried using different flags then kAuthorizationFlagDefaults, but that led to either the same problem or error code -60011 - invalid flags. What am I doing wrong here, please?

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  • Why do I get this strange output behavior?

    - by WilliamKF
    I have the following program test.cc: #include <iostream> unsigned char bogus1[] = { // Changing # of periods (0x2e) changes output after periods. 0x2e, 0x2e, 0x2e, 0x2e }; unsigned int bogus2 = 1816; // Changing this value changes output. int main() { std::clog << bogus1; } I build it with: g++ -g -c -o test.o test.cc; g++ -static-libgcc -o test test.o Using g++ version 3.4.6 I run it through valgrind and nothing is reported wrong. However the output has two extra control characters and looks like this: .... Thats a control-X and a control-G at the end. If you change the value of bogus2 you get different control characters. If you change the number of periods in the array the issue goes away or changes. I suspect it is a memory corruption bug in the compiler or iostream package. What is going on here?

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  • Garbage data from serial port.

    - by sasayins
    Hi I wrote a code in Linux platform that read the data in serial port, my code below: int fd; char *rbuff=NULL; struct termios new_opt, old_opt; int ret; fd = open("/dev/ttyS0", O_RDWR | O_NOCTTY); if( fd == -1 ) { printf("Can't open file: %s\n", strerror(errno)); return -1; } tcgetattr(fd, &old_opt); new_opt.c_cflag = B115200 | CS8 | CLOCAL | CREAD; new_opt.c_iflag = IGNPAR /*| ICRNL*/; new_opt.c_oflag = 0; new_opt.c_lflag = ICANON; tcsetattr(fd, TCSANOW, &new_opt); rbuff = malloc(NBUFF); printf("reading..\n"); memset(rbuff,0x00,NBUFF); ret = read(fd, rbuff, NBUFF); printf("value:%s",rbuff); if(ret == -1) { printf("Read error:%s\n",strerror(errno)); return -1; } tcsetattr(fd, TCSANOW, &old_opt); close(fd); My problem is the code above doesn't read the first data that was transmitted, then the second transmission the data is garbage, then the third is the normal data. Did I missed a setting in the serial port? Thanks.

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  • Function calculating the probability of a letter in an sentence

    - by Mike
    I have a function that is supposed to calculate the number of times a letter occurs in a sentence, and based on that, calculate the probability of it occurring in the sentence. To accomplish this, I have a sentence: The Washington Metropolitan Area is the most educated and affluent metropolitan area in the United States. An array of structures, containing the letter, the number of times it occurs, and the probability of it occurring, with one structure for each letter character and an additional structure for punctuation and spaces: struct letters { char letter; int occur; double prob; }box[53]; This is the function itself: void probability(letters box[53], int sum { cout<<sum<<endl<<endl; for(int c8=0;c8<26;c8++) { box[c8].prob = (box[c8].occur/sum); cout<<box[c8].letter<<endl; cout<<box[c8].occur<<endl; cout<<box[c8].prob<<endl<<endl; } } It correctly identifies that there are 90 letters in the sentence in the first line, prints out the uppercase letter as per the structure in the second line of the for loop, and prints out the number of times it occurs. It continually prints 0 for the probability. What am I doing wrong?

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  • What's the most trivial function that would benfit from being computed on a GPU?

    - by hanDerPeder
    Hi. I'm just starting out learning OpenCL. I'm trying to get a feel for what performance gains to expect when moving functions/algorithms to the GPU. The most basic kernel given in most tutorials is a kernel that takes two arrays of numbers and sums the value at the corresponding indexes and adds them to a third array, like so: __kernel void add(__global float *a, __global float *b, __global float *answer) { int gid = get_global_id(0); answer[gid] = a[gid] + b[gid]; } __kernel void sub(__global float* n, __global float* answer) { int gid = get_global_id(0); answer[gid] = n[gid] - 2; } __kernel void ranksort(__global const float *a, __global float *answer) { int gid = get_global_id(0); int gSize = get_global_size(0); int x = 0; for(int i = 0; i < gSize; i++){ if(a[gid] > a[i]) x++; } answer[x] = a[gid]; } I am assuming that you could never justify computing this on the GPU, the memory transfer would out weight the time it would take computing this on the CPU by magnitudes (I might be wrong about this, hence this question). What I am wondering is what would be the most trivial example where you would expect significant speedup when using a OpenCL kernel instead of the CPU?

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  • How is the C++ synthesized move constructor affected by volatile and virtual members?

    - by user1827766
    Look at the following code: struct node { node(); //node(const node&); //#1 //node(node&&); //#2 virtual //#3 ~node (); node* volatile //#4 next; }; main() { node m(node()); //#5 node n=node(); //#6 } When compiled with gcc-4.6.1 it produces the following error: g++ -g --std=c++0x -c -o node.o node.cc node.cc: In constructor node::node(node&&): node.cc:3:8: error: expression node::next has side-effects node.cc: In function int main(): node.cc:18:14: note: synthesized method node::node(node&&) first required here As I understand the compiler fails to create default move or copy constructor on line #6, if I uncomment either line #1 or #2 it compiles fine, that is clear. The code compiles fine without c++0x option, so the error is related to default move constructor. However, what in the node class prevents default move constructor to be created? If I comment any of the lines #3 or #4 (i.e. make the destructor non-virtual or make data member non-volatile) it compiles again, so is it the combination of these two makes it not to compile? Another puzzle, line #5 does not cause an compilation error, what is different from line #6? Is it all specific for gcc? or gcc-4.6.1?

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  • Convert this code from C++ to C#

    - by Alhariri
    please any one convert this code from c++ to c# beacuse i dont know how to read from file in c++ please help me int DoEnDe(int c) { SDES S(key); int i,n; n=10; //Number of Rounds unsigned char ch; FILE *fp; FILE *ft; fp=fopen(tfname,"w"); ft=fopen(sfname,"r"); if (fp==NULL) { printf("\nTarget File not opened SORRY"); getch(); fclose(fp); return(0); } if (ft==NULL) { printf("\nSource File not opened SORRY"); getch(); fclose(ft); return(0); } while (fread(&ch,1,1,ft)==1) { S.OUTPUT=ch; for (i=0;i<n;i++) { if (c==1) S.DES_Encryption(S.OUTPUT); if (c==2) S.DES_Decryption(S.OUTPUT); } fwrite(&S.OUTPUT,1,1,fp); } printf("\nCompleted!!!!!"); getch(); fclose(fp); fclose(ft); return(1); }

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  • Using an initializer_list on a map of vectors

    - by Hooked
    I've been trying to initialize a map of <ints, vector<ints> > using the new 0X standard, but I cannot seem to get the syntax correct. I'd like to make a map with a single entry with key:value = 1:<3,4 #include <initializer_list> #include <map> #include <vector> using namespace std; map<int, vector<int> > A = {1,{3,4}}; .... It dies with the following error using gcc 4.4.3: error: no matching function for call to std::map<int,std::vector<int,std::allocator<int> >,std::less<int>,std::allocator<std::pair<const int,std::vector<int,std::allocator<int> > > > >::map(<brace-enclosed initializer list>) Edit Following the suggestion by Cogwheel and adding the extra brace it now compiles with a warning that can be gotten rid of using the -fno-deduce-init-list flag. Is there any danger in doing so?

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  • Simple C++ code (what's wrong here?)

    - by JW
    Noob to C++. I'm trying to get user input (Last Name, First Name Middle Name), change part of it (Middle Name to Middle Initial) and then rearrange it (First Middle Initial Last). Where am I messing up in my code? --Thanks for ANY help you can offer! ... #include <iostream> using std::cout; using std::cin; #include <string> using std::string; int main() { string myString, last, first, middle; cout << "Enter your name: Last, First Middle"; cin >> last >> first >> middle; char comma, space1, space2; comma = myString.find_first_of(','); space1 = myString.find_first_of(' '); space2 = myString.find_last_of(' '); last = myString.substr (0, comma); // user input last name first = myString.substr (space1+1, -1); // user input first name middle = myString.substr (space2+1, -1); // user input middle name middle.insert (0, space2+1); // inserts middle initial in front of middle name middle.erase (1, -1); // deletes full middle name, leaving only middle initial myString = first + ' ' + middle + ' ' + last; // return 0; }

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  • Building argv and argc

    - by Wylie Coyote SG.
    I'm a student programmer using Qt to build a GUI application for work. The primary purpose of this application is to open some of our old style files, allows better editing and then save the file in a new format and file extension. Recently I have been asked to allow this conversion to take place from a terminal. While I do know what argv and argc are along with what they represent I am unsure how to accomplish what they want. For instance how to handle relative paths vs. absolute... maybe how to get absolute from relative; perhaps none of that is even needed. My programming experience has been primarily with guis so this is a little new to me. Users would like the following to be ran from the terminal application -o /fileLocation /fileDestination template(to determine new format) I began to use for loops and if statements to begin accomplishing this when I relized that I might be taking the worng approach to all of this. I WOULD ALSO BE REALLY INTERESTED IF QT HAS SOMETHING FOR THIS! Here is what I have began coming up with: int main(int argc, char *argv[]) { if(argc > 1) { for(int i = 0; i < argc; i++) { if(argv[i] == "-c") { QString fileName = QString::fromStdString(argv[i+1]); QString fileDestination = QString::fromStdString(argv[i+2]); QString templateName = QString::fromStdString(argv[i+3]); QFile fileToConvert(fileName); if(fileToConvert.open(QFile::ReadOnly)) { //do stuff Thanks for reading my post and a big thanks for any contributions you make to helping me overcome this issue.

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