Search Results

Search found 9889 results on 396 pages for 'pointer speed'.

Page 271/396 | < Previous Page | 267 268 269 270 271 272 273 274 275 276 277 278  | Next Page >

  • Array of char *

    - by user353060
    Hello, I am having problems with array pointers. I've looked through Google and my attempts are futile so far. What I would like to do is, I have a char name[256]. I will be 10 of those. Hence, I would need to keep track of each of them by pointers. Trying to create a pointer to them. int main() { char superman[256] = "superman"; char batman[256] = "batman"; char catman[256] = "catman"; char *names[10]; names[0] = superman; names[1] = batman; system("pause"); return 0; } How do I actually traverse an array of pointers?

    Read the article

  • Double indirection and structures passed into a function

    - by ZPS
    I am curious why this code works: typedef struct test_struct { int id; } test_struct; void test_func(test_struct ** my_struct) { test_struct my_test_struct; my_test_struct.id=267; *my_struct = &my_test_struct; } int main () { test_struct * main_struct; test_func(&main_struct); printf("%d\n",main_struct->id); } This works, but pointing to the memory address of a functions local variable is a big no-no, right? But if i used a structure pointer and malloc, that would be the correct way, right? void test_func(test_struct ** my_struct) { test_struct *my_test_struct; my_test_struct = malloc(sizeof(test_struct)); my_test_struct->id=267; *my_struct = my_test_struct; } int main () { test_struct * main_struct; test_func(&main_struct); printf("%d\n",main_struct->id); }

    Read the article

  • Is it possible to generate plain-old XML using Haml?

    - by lsdr
    I've been working on a piece of software where I need to generate a custom XML file to send back to a client application. The current solutions on Ruby/Rails world for generating XML files are slow, at best. Using builder or event Nokogiri, while have a nice syntax and are maintainable solutions, they consume too much time and processing. I definetly could go to ERB, which provides a good speed at the expense of building the whole XML by hand. HAML is a great tool, have a nice and straight-forward syntax and is fairly fast. But I'm struggling to build pure XML files using it. Which makes me wonder, is it possible at all? Does any one have some pointers to some code or docs showing how to do this, build a full, valid XML from HAML?

    Read the article

  • Drupal: Programmatically saving imagefield images

    - by Ace
    Hey there! I'm trying to write a sync function that saves some data to nodes, which works fine, until I try to save the thumbnail image associated with the node. I've managed to download the file and put it in my sites/default/files folder, but what's the best way to tell Drupal, "put this file in that CCK imagefield"? EDIT To clarify a bit.. I sync the thumbnails separately (since one image can be used by several nodes)... I would like the initial thumbnail sync to save the files in the correct folder (not a temp one) and just point the imagefield to this file... That's what annoys me with field_file_save_file(), it saves a new file instead of just making a pointer.. Any advice?

    Read the article

  • Objective-C: Initializing char with char at index of string.

    - by Mr. McPepperNuts
    unichar myChar = [myString characterAtIndex:0]; [myNSMutableArray addObject:myChar]; I am trying to insert the first char of a string into an array, to create an array of chars. the first line does not give me an error. The second line however, provides the following error: warning: passing argument 1 of 'addObject:' makes pointer from integer without a cast This also crashes the application with a "bad address" error. I thought this error was due to a problem with memory allocation. Can someone shed some light on this.

    Read the article

  • Are raw C++ pointers first class objects?

    - by Shailesh Kumar
    According to Wikipedia: An object is first-class when it: can be stored in variables and data structures can be passed as a parameter to a subroutine can be returned as the result of a subroutine can be constructed at runtime has intrinsic identity (independent of any given name) Somebody had once told me that raw pointers are not first class objects while smart pointers like std::auto_ptr are. But to me, a raw pointer (to an object or to a function) in C++ does seem to me to satisfy the conditions stated above to qualify as a first class object. Am I missing something?

    Read the article

  • Resources for learning how to better read code

    - by rsteckly
    Hi, I recently inherited a large codebase and am having to read it. The thing is, I've usually been the dev starting a project. As a result, I don't have a lot of experience reading code. My reaction to having to read a lot of code is, well, umm to rewrite it. But I need to bring myself up to speed quickly and build on top of an existing system. Do other people have techniques they've learned to absorb a code base? At this point, I'm just reading through the code. I've tried generating UML diagrams using UModel. They're so big they won't print cleanly and when I zoom in, I really do lose the perspective of seeing all the relationships. How have other people dealt with this problem?

    Read the article

  • Android internet connectivity check problem

    - by Chaoz
    Hello, I'm new to Android development and working on an Android application that requires the phone to be connected to the internet, through either Wifi, EDGE or 3G. This is the code that I'm using: public static boolean isConnected() { ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE); return cm.getActiveNetworkInfo().isConnectedOrConnecting(); } I've also set these permissions in the manifest file: <uses-permission android:name="android.permission.INTERNET" /> <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" /> This works fine in the emulator running version 1.5 of Android when 3G is enabled, but it crashes when I disable the 3G connection. My application throws a null pointer exception when I call isConnectedOrConnecting(). Hope that anyone knows the solution to this. Thanks in advance!

    Read the article

  • Why does accessing a member of a malloced array of structs seg fault?

    - by WSkinner
    I am working through Learn C The Hard Way and am stumped on something. I've written a simplified version of the problem I am running into to make it easier to get down to it. Here is the code: #include <stdlib.h> #define GROUP_SIZE 10 #define DATA_SIZE 64 struct Dummy { char *name; }; struct Group { struct Dummy **dummies; }; int main() { struct Group *group1 = malloc(sizeof(struct Group)); group1->dummies = malloc(sizeof(struct Dummy) * GROUP_SIZE); struct Dummy *dummy1 = group1->dummies[3]; // Why does this seg fault? dummy1->name = (char *) malloc(DATA_SIZE); return 0; } when I try to set the name pointer on one of my dummies I get a seg fault. Using valgrind it tells me this is uninitialized space. Why is this?

    Read the article

  • Maven Quick-start Guide

    - by Dave
    I'm tasked with getting a development environment set up for a new program at work. The lead has chosen Eclipse as the IDE for its OSGi support and Maven as the build utility. I've struggled through getting Maven integrated with Eclipse and I'm grudgingly declaring success and moving forward. My question: is there any sort of guide to getting started with Maven? I've found boatloads of documentation, most all of it very, very detailed and simultaneously unhelpful. I downloaded a 300+ page book that goes into excruciating detail about POMs, but doesn't tell you how to initialize a project from existing source. Hopefully, this question will result in a pointer to something I missed or a collection of links for those who follow me.

    Read the article

  • Boost singleton and undefined reference

    - by Ockonal
    Hello, I globally use singleton pattern in my project. To make it easier - boost::singleton. Current project uses Ogre3d library for rendering. Here is some class: class GraphicSystem : public singleton<GraphicSystem> { private: Ogre::RenderWindow *mWindow; public: Ogre::RenderWindow *getWindow() const { return mWindow; } }; In GraphicSystem constructor I fill the mWindow value: mWindow = mRoot->createRenderWindow(...); I cheked it, everything makes normally. So, now I have to use handler for the window in input system (to get window handle). Somewhere else in another class: Ogre::RenderWindow *temp = GraphicSystem::get_mutable_instance().getWindow(); GraphicSystem::get_mutable_instance().getWindow()->getCustomAttribute("WINDOW", &mWindowHandle); temp is 0x00, and there is segfault at last line (getting custon attribute). I can't understand, why does singleton returns undefined pointer for the window. All another singleton-based classes work well.

    Read the article

  • Compatible types and structures in C

    - by Oli Charlesworth
    I have the following code: int main(void) { struct { int x; } a, b; struct { int x; } c; struct { int x; } *p; b = a; /* OK */ c = a; /* Doesn't work */ p = &a; /* Doesn't work */ return 0; } which fails to compile under GCC (3.4.6), with the following error: test.c:8: error: incompatible types in assignment test.c:9: warning: assignment from incompatible pointer type Now, from what I understand (admittedly from the C99 standard), is that a and c should be compatible types, as they fulfill all the criteria in section 6.2.7, paragraph 1. I've tried compiling with std=c99, to no avail. Presumably my interpretation of the standard is wrong?

    Read the article

  • status failed for LdrLoadDll

    - by kiddo
    hello all,I'am trying to work-out the LdrLoadDll function and am having no luck with that..i also googled for some examples there is no much documentation or correct example about this.I know what it exactly does..Please check the code below. //declaration function pointer for LdrLoadDll typedef NTSTATUS (_stdcall*fp_LdrLoadDll)( IN PWCHAR PathToFile OPTIONAL, IN ULONG Flags OPTIONAL, IN PUNICODE_STRING ModuleFileName, OUT PHANDLE ModuleHandle ); //calling LdrLoadDll using getprocaddress HANDLE handle; HMODULE module = LoadLibrary(L"ntdll.dll"); fp_LdrLoadDll loadDll; loadDll = (fp_LdrLoadDll)GetProcAddress(module,"LdrLoadDll"); if(loadDll == NULL) { MessageBox(0,L"Not able to load the function",L"LdrLoadDll",&handle); } UNICODE_STRING input; input.Buffer = L"C:\\Desktop\\myDll.dll"; input.Length = wcslen(input.Buffer)*2; input.MaximumLength = wcslen(input.Buffer) +2; NTSTATUS status = loadDll(NULL,LOAD_WITH_ALTERED_SEARCH_PATH,&input,0); When i execute the above am not getting the handle niether valid status.Please help me with this.

    Read the article

  • Scalable (half-million files) version control system

    - by hashable
    We use SVN for our source-code revision control and are experimenting using it for non-source-code files. We are working with a large set (300-500k) of short (1-4kB) text files that will be updated on a regular basis and need to version control it. We tried using SVN in flat-file mode and it is struggling to handle the first commit (500k files checked in) taking about 36 hours. On a daily basis, we need the system to be able to handle 10k modified files per commit transaction in a short time (<5 min). My questions: Is SVN the right solution for my purpose. The initial speed seems too slow for practical use. If Yes, is there a particular svn server implementation that is fast? (We are currently using the gnu/linux default svn server and command line client.) If No, what are the best f/oss/commercial alternatives Thanks

    Read the article

  • Apache server-side files caching via .htaccess?

    - by purpler
    Hi, I'm starting new website and gonna include several JS libs and would like to know how .htaccess file template should look like with caching of media and JS files on? Whats better for compression, GZip or Deflate? Is it better/faster solution to serve those JS libs of the Google CDN perhaps then locally? I'm asking CDN question since some of scripts served off GoogleCDN are potentially going to update and eventually break the website layout so i thought it would be better for me to host them locally and cache via webserver if its going to work with same/near-same speed.

    Read the article

  • str_replace() with two-dimensional array

    - by Qiao
    You can use arrays with str_replace(): $array_from = array ('from1', 'from2'); $array_to = array ('to1', 'to2'); $text = str_replace ($array_from, $array_to, $text); But what if you have two-dimensional array? $array_from_to = array ( 'from1' => 'to1'; 'from2' => 'to2'; ); How can you use it with str_replace()? Speed matters - array is big enough.

    Read the article

  • Objective C LValue required as unary '&' operand

    - by Bob
    Hello! In my code, I get this error when I try to get a pointer to my class property. (I wrote a small *.OBJ file translator in Python, discarding the normals) CODE: //line: line of text const char *str = [line UTF8String]; Point3D *p1, *p2, *p3; p1 = [Point3D makeX:0 Y:0 Z:0]; p2 = [Point3D makeX:0 Y:0 Z:0]; p3 = [Point3D makeX:0 Y:0 Z:0]; sscanf(str, "t %f,%f,%f %f,%f,%f %f,%f,%f",(&[p1 x]),&([p1 y]),&([p1 z]),&([p2 x]),&([p2 y]),&([p2 z]),&([p3 x]),&([p3 y]),&([p3 z])); Triangle3D *tri = [Triangle3D make:p1 p2:p2 p3:p3];

    Read the article

  • Handle/Grip bar convention

    - by tomdemuyt
    Greetings, Because textarea elements do not resize with jquery.touch ( http://plugins.jquery.com/project/touch ), I've put an textarea in a table where the first row allows the user to drag the table around and resize it with the textarea growing/shrinking/moving along. It works well, except that users dont seem to 'get' that they can use the bar to resize/move. I was trying to find some 'grip bar' graphics but google isnt helping me. What is the best way to show users that an element can be moved/resized ? Pointer to graphics ( generators ) would be great. Or, does any one know how to make textarea's movable/resizable ? T.

    Read the article

  • Extract anything that looks like links from large amount of data in python

    - by Riz
    Hi, I have around 5 GB of html data which I want to process to find links to a set of websites and perform some additional filtering. Right now I use simple regexp for each site and iterate over them, searching for matches. In my case links can be outside of "a" tags and be not well formed in many ways(like "\n" in the middle of link) so I try to grab as much "links" as I can and check them later in other scripts(so no BeatifulSoup\lxml\etc). The problem is that my script is pretty slow, so I am thinking about any ways to speed it up. I am writing a set of test to check different approaches, but hope to get some advices :) Right now I am thinking about getting all links without filtering first(maybe using C module or standalone app, which doesn't use regexp but simple search to get start and end of every link) and then using regexp to match ones I need.

    Read the article

  • If free() knows the length of my array, why can't I ask for it in my own code?

    - by Chris Cooper
    I know that it's a common convention to pass the length of dynamically allocated arrays to functions that manipulate them: void initializeAndFree(int* anArray, int length); int main(){ int arrayLength = 0; scanf("%d", &arrayLength); int* myArray = (int*)malloc(sizeof(int)*arrayLength); initializeAndFree(myArray, arrayLength); } void initializeAndFree(int* anArray, int length){ int i = 0; for (i = 0; i < length; i++) { anArray[i] = 0; } free(anArray); } but if there's no way for me to get the length of the allocated memory from a pointer, how does free() "automagically" know what to deallocate? Why can't I get in on the magic, as a C programmer? Where does free() get its free (har-har) knowledge from?

    Read the article

  • migrating C++ code from structures to classes

    - by eSKay
    I am migrating some C++ code from structures to classes. I was using structures mainly for bit-field optimizations which I do not need any more (I am more worried about speed than saving space now). What are the general guidelines for doing this migration? I am still in the planning stage as this is a very big move affecting a major part of the code. I want to plan everything first before doing it. What are all the essential things I should keep in mind?

    Read the article

  • c++/cli pass (managed) delegate to unmanaged code

    - by Ron Klein
    How do I pass a function pointer from managed C++ (C++/CLI) to an unmanaged method? I read a few articles, like this one from MSDN, but it describes two different assemblies, while I want only one. Here is my code: 1) Header (MyInterop.ManagedCppLib.h): #pragma once using namespace System; namespace MyInterop { namespace ManagedCppLib { public ref class MyManagedClass { public: void DoSomething(); }; }} 2) CPP Code (MyInterop.ManagedCppLib.cpp) #include "stdafx.h" #include "MyInterop.ManagedCppLib.h" #pragma unmanaged void UnmanagedMethod(int a, int b, void (*sum)(const int)) { int result = a + b; sum(result); } #pragma managed void MyInterop::ManagedCppLib::MyManagedClass::DoSomething() { System::Console::WriteLine("hello from managed C++"); UnmanagedMethod(3, 7, /* ANY IDEA??? */); } I tried creating my managed delegate and then I tried to use Marshal::GetFunctionPointerForDelegate method, but I couldn't compile.

    Read the article

  • Interpreter in C++: Function table storage problem

    - by sub
    In my interpreter I have built-in functions available in the language like print exit input, etc. These functions can obviously be accessed from inside the language. The interpreter then looks for the corresponding function with the right name in a vector and calls it via a pointer stored with its name. So I gather all these functions in files like io.cpp, string.cpp, arithmetic.cpp. But I have to add every function to the function list in the interpreter in order for it to be found. So in these function files I have things like: void print( arg ) { cout << arg.ToString; } I'd add this print function to the interpreter function list with: interpreter.AddFunc( "print", print ); But where should I call the interpreter.AddFunc? I can't just put it there below the print function as it has to be in a function according to the C++ syntax. Where and how should all the functions be added to the list?

    Read the article

  • Indexing datetime in MySQL

    - by User1
    What is the best way to index a datetime in MySQL? Which method is faster: Store the datetime as a double (via unix timestamp) Store the datetime as a datetime The application generating the timestamp data can output either format. Unfortunately, datetime will be a key for this particular data structure so speed will matter. Also, is it possible to make an index on an expression? For example, index on UNIX_TIMESTAMP(mydate) where mydate is a field in a table and UNIX_TIMESTAMP is a mysql function. I know that Postgres can do it. I'm thinking there must be a way in mysql as well.

    Read the article

  • The shortest way to convert infix expressions to postfix (RPN) in C

    - by kuszi
    Original formulation is given here (you can try also your program for correctness) . Additional rules: 1. The program should read from standard input and write do standard output. 2. The program should return zero to the calling system/program. 3. The program should compile and run with gcc -O2 -lm -s -fomit-frame-pointer. The challenge has some history: the call for short implementations has been announced at the Polish programming contest blog in September 2009. After the contest, the shortest code was 81 chars long. Later on the second call has been made for even shorter code and after the year matix2267 published his solution in 78 bytes: main(c){read(0,&c,1)?c-41&&main(c-40&&(c%96<27||main(c),putchar(c))):exit(0);} Anyone to make it even shorter or prove this is impossible?

    Read the article

< Previous Page | 267 268 269 270 271 272 273 274 275 276 277 278  | Next Page >