I have some expressions such as x^2+y^2 that I'd like to use for some math calculations. On of the things I'd like to do is to take partial derivatives of the expressions. So if f(x,y) = x^2 + y^2 then the partial of f with respect to x would be 2x, the partial with respect to y would be 2y. I wrote a dinky function using a finite differ...
I've (re)started working in C after about 3 years:) And i discovered that my C language skills arent that good anymore. Can anyone recommend an online book for C? (not C++) It should cover the basic functions, plus pointers, and working with linear lists, reading from files..etc. This things are covered by basically any book for beginne...
I need to access the crypto functions of OpenSSL to encode Blowfish data in a CBC streams. I've googled and found some Blowfish libraries (hand written) and some OpenSSL wrappers (none of the seem complete.) In the end, I need to access the certain OpenSSL functions, such as the full blowfish.h library of commands. What's the pythonic/r...
Simple question: do I have to 'delete' or 'delete []' c? Does the language matter? char c[] = "hello" ...
As a follow-up to this question: From what I've seen, this should work as expected: void greet(){ char c[] = "Hello"; greetWith(c); return; } but this will cause undefined behavior: char *greet(){ char c[] = "Hello"; return c; } If I'm right, what's the best way to fix the second greet function? In an embedded environme...
The OpenGroup POSIX.1-2001 defines strerror_r, as does The Linux Standard Base Core Specification 3.1. But I can find no reference to the maximum size that could be reasonably expected for an error message. I expected some define somewhere that I could put in my code but there is none that I can find. The code must be thread safe. Whic...
Instruction on accessing a interface to an application, in plain C/C++ without: MFC ATL WTL Basically, I would like to make use of a COM object. Working sample source code or guidance - to using (functionality) a COM object, not creating a COM server. Regards ...
Hey guys, I am currently trying to learn C and I have come to a problem that I've been unable to solve. Consider: #include <stdio.h> #include <stdlib.h> #include <string.h> #define ELEMENTS 5 void make(char **array, int *array_size) { int i; char *t = "Hello, World!"; array = malloc(ELEMENTS * sizeof(char *)); for ...
I want to get the MIME type from a filename using C. Is there a way to do this without using a textfile containing MIME types and file extensions (i.e. Apache's file mime.types)? Maybe there is a function to get the MIME type using the filename? I rather not use the file extension if I don't have to. ...
We have a .lib file with functionality that must be included in a Delphi application. It is easy to include .obj files, but for some unknown reason, this won't work for .lib files. The help is not very helpful on this. And a google search did not help that much (most helpful was to use an other linker but I would like to avoid it if pos...
I have some code that uses the Oracle function add_months to increment a Date by X number of months. I now need to re-implement the same logic in a C / C++ function. For reasons I don't want/need to go into I can't simply issue a query to oracle to get the new date. Does anyone know of a simple and reliable way of adding X number of m...
I'd like to use a virtual machine like NekoVM into a small device but to build it, it requires Boehm GC, however there is no port of that GC to that small device so I was wondering if there is any alternative to it, something that could be done exclusively with C code? ...
What is the relationship between the Windows API and the C run time library? ...
Can you guys tell me the difference between them? BTW is there something called C++ library or C library?? Thanks. Dazza ...
I'd like to profile a program that forks and spawns several child processes. I want to see how much time is spent in some of the functions. What profiler can handle this job? ...
Given a struct, e.g. typedef struct { int value; } TestStruct; Why does the following code (in the context of an Objective-C class running on the IPhone) throw a "non-aligned pointer being freed" exception? TestStruct ts = {33}; free(&ts); N.B. My uber goal is to use a C library with many vector-math functions, hence the need to ...
Consider the following: typedef struct { float m00, m01, m02, m03; float m10, m11, m12, m13; float m20, m21, m22, m23; float m30, m31, m32, m33; } Matrix; @interface TestClass : NSObject { Matrix matrix; } - (TestClass *) init; @end @implementation TestClass - (TestClass *) init { self = [super init]; matrix = (Matri...
I came across a reference to it recently on proggit and (as of now) it is not explained. I suspect this might be it, but I don't know for sure. ...
Hello, I try to encrypt simple text with RSA algorithm. I have a problem with my code. RSA *_RSA ; unsigned char text[2560] = "A"; unsigned char sectext[2560]; unsigned char decrypttext[2560]; int i = 0; _RSA = RSA_generate_key ( 1024, 65537, NULL, NULL ); i = RSA_public_encrypt ( 1, text, sectext, _RSA, RSA_PKCS1_OAEP_PA...
Is there an easy way to compile c code in visual studio 2005? Its been a while(2-3 years) since I've done any coding in either c or c++, but I remember that you used to be able ti, in vs 2003, compile c code in visual studio. I thought it was just a matter of using an empty project(rather than, say a c++ project or a C# project) and gi...