Hey there, this is my first post so please don't be too hard on me. I wrote an "insert" function to insert an integer into an array of integers. It works, but I don't know if it's the best algorithm. Here's my code: int* insert(int *dest, size_t len, unsigned int index, int value) { int x = 0, i = 0; int *stackp = calloc(len+1, sizeof...
I am writing C / C++ code to run a shell command and capture the output: static const int BUFFER_SIZE=512; // (...) FILE* pipe; char buffer[BUFFER_SIZE]; // (...) if (!(pipe = popen(cmd.c_str(), "r"))) { out("\nProblem executing command: " + cmd + "\n"); return 1; } while (!feof(pipe)) { int read = fread(buffer, sizeof(char),...
C is always pretty awkward with strings, but it's usually okay to just allocate a char array of size 256 for your string and be on with it. However, what if you want the function to return a string and you don't know the size, since you will be concatenating strings together dozens or hundreds of times? Obviously something like this ...
Sometimes, when I have a multi-case if, or a very simple for, with only two statements, I will forgo braces, instead using the comma. Is this a bad exploitation of the feature, and is it ugly and bad form? Or is it an acceptable way to save time and space? For example: if (something) b = y, c = z--; instead of: if (something) { ...
Possible Duplicate: Potential Problem in Swapping values of two variables without using a third variable I recently read in a community that we can easily swap two numbers without using third using a XOR trick. m^=n^=m^=n; trick was mentioned. What do you guys think? Is this trick always useful? ...
In C, it's not an error to cast pointers to and from void *. A major obstacle in porting to C++ is the need to cast pointers when returning from functions dealing with generic pointers such as malloc, and functions declared in my own code such as void *block_get(Blkno const blkno);. My code however is intended to be compiled by C and C...
Possible Duplicates: Empty class in C++ What is the size of an empty struct in C? I read somewhere that size of an empty struct in C++ is 1. So I thought of verifying it. Unfortunately I saved it as a C file and used <stdio.h> header and I was surprised to see the output. It was 0. That means struct Empty { }; int main(v...
Hello, I'm writing a C++ application which shall be locale independent, so I decided to use UTF-16 as my in-memory representation for strings/texts (the application should be as platform independent as possible). For localize the application's messages i want to use GNU's gettext library. Since this library seems to use GNU's libunistri...
Given the files: // file: q7a.h static int err_code = 3; void printErrCode (); ///////////// END OF FILE ///////////////// // file: q7a.c #include <stdio.h> #include "q7a.h" void printErrCode () { printf ("%d ", err_code); } ///////////// END OF FILE ///////////////// // file: q7main.c #include "q7a.h" int main() { err_code = 5; printEr...
I want to make this code run, but I'm still too much of a n00b on C, and OpenGL and VS 2008 to identify on which of them is the fault: #include <stdio.h> #include <stdlib.h> #include <GL/glut.h> #include<math.h> void init(void) { //set display-window background color to white glClearColor(1.0,1.0,1.0,0.0); //set projection paramaters...
There is no function as sqlite3_column_date which I need: int i = 0; for (NSString *key in [self valuesWithTypes]) { id value; if ([[[self valuesWithTypes] objectForKey:key] isKindOfClass:[NSString class]]) { value = [[NSString stringWithUTF8String:(char *)sqlite3_column_text(statement, i)] autorelease]; } else if ([[[self v...
I'm developing a product that is interfaced over USB. I want to write a control app for it, but I cannot program a GUI for poo, so I came up with the idea of using a web page (local to the app's install directory) as the interface to the program. So, the line of communication would be: User --> HTML page (not hosted - it's local) --> C+...
void main(void) { int x,y,z; x=y=z=1; z = x && y && ++z;//is this fine? } I have lately started reading about sequence points stuffs but I cannot figure out whether the above sample of code is fine or not. I know the && operator introduces a sequence point so I am not very sure about the behavior of the expression z = x && y && ...
I have read in K&R that functions containing more than one word should be capitalized.Should one-word functions like prime(),be written as Prime()?Is this a good practise? ...
Why does this code not work as expected? #include <cstdio> int main() { char mona[] = "\x50\x4e\x47\x0d\x0a\x1a\x0a\x00\x00\x00\x0d\x49\x48\x44\x52\x00\x00\x01\x90" "\x00\x00\x02\x5d\x01\x03\x00\x00\x00\x26\xef\xb3\x78\x00\x00\x00\x45\x74\x45\x58" // <snip> "\x00\x49...
The comma , items separator used in an array initialization list may end the list in C, this is mentioned in The C Programming Language 2nd ed by Kernighan & Ritchie . e.g. int c[] = { 1, 2, 3, }; This is convenient when the list is long, and one doesn't want to have to change/check the previous line when adding items long long...
error: dereferencing pointer to incomplete type The problem line is "gl->point[0] = (struct list *)" I read somewhere that I could be storing a declaration. If that is the case I need that explained to me. struct ref { char **name; struct list **point; }; int main ( ) { typedef struct { char **name; s...
I implemented strstr() myself,the code works fine for all strings but when the string lies in the first index of the string,it returns null. #include<stdio.h> const char* mystrstr(const char *str1, const char *str2); int main() { const char *str1="chal bhai nikal"; const char *str2="c",*result; result=mystrstr(str1,str2); if(*resu...
I'm pretty new to C, so I apologize if this is pretty standard knowledge.. I have a function like so, where I am appending a bunch of C-style strings together and outputting it: char *example(int n, int days, int years){ char *ret; if (n < 5) { ret = (char*)malloc(sizeof(char)*256); sprintf(ret, "There are %d da...
Hello, I've been playing with DOS real mode assembly for a while and now I want to utilize some routines in a C program. I'm using Turbo C 2.01 and TASM 3.0. I'm however unable to modify a variable passed by address, see the _setval routine below. I don't need/want inline assembly. A simple example: foo.c #include <stdio.h> extern voi...