C is a general-purpose computer programming language used for operating systems, games and other high performance work.

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Assigning strings to pointer in C Language

I am a new learner of C language, my question is about pointers. As far i learned and searched pointers can only store addresses of other variables, but cannot store the actual values(like integers or ...
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Use of malloc in C

Is it necessary to call free function every time we use malloc in C. I am asking this because I have seen many times that it is not called . Thank you
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How to efficiently store IP addresses? [closed]

Background I have a requirement where I need to remove a few nodes in a network based upon a command given by the user. To keep the nodes from transmitting or receiving data I thought of changing its ...
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697 views

Implementing a priority queue with a circular array

[If this fits more to stackoverflow then transfer it there please.] Hi, I'm trying to implement a priority queue in C. The easiest way I found to do it is with a circular array (rather than using a ...
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How are negative signed values stored? [duplicate]

I was watching this video on the maximum and minimum values of signed integers. Take an example of a positive signed value - 0000 0001 The first bit denotes that the number is positive and the last ...
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67 views

Use one or multiple files for graphics properties?

I'm creating a 2D game in plain ANSI-C using SDL2. I'm planning to let users create their own graphics. So, to achieve this, I'll use an information file which will hold some data such as Width, ...
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269 views

ANSI C pointers corrupted values

I am working on ANSI C and having some issues with the pointers. That is that after a point in my program the pointer's values change without me interfering, is something like overwriting them. I ...
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I'm trying to figure out which functions from one C library are being used by C project. Does anyone have a simple solution? [closed]

To be specific, I want to know which function/types in libpri and being used in the Asterisk project. I'm not traditionally a C programmer, but I know some basic stuff because I took a class in ...
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1answer
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floating-point number stored in float variable has other value [duplicate]

I'm reading a book about C programming By "King.K.N" and I'm reading the following statement: If we store 0.1 in a float variable, we may later find that the variable has a value such as ...
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139 views

Can i create a function with variable parameters in C?

I've always wondered where a single function such as printf(); can take in variable parameters and provide the right results. For example, printf("Number is %d",a); which has two parameters, and ...
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210 views

Exercise in 1.6 C by Kernighan and Ritchie

I'm using this book by Kernighan and Ritchie, on the chapter about character input and output and file copying, I'm totally lost as to what this chapter is talking about. This question may seem too ...
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137 views

How much does C help you in other languages? [duplicate]

How much does learning C to moderate level help you as a programmer. For example, does being competent in C make it easier to pick up languages as time goes on and get a better understanding of them?
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258 views

Best online reference guide for gcc [closed]

My box is configured: Ubuntu, Code::Blocks IDE, GNU gcc compiler. I'm not very experienced in C. I am having some difficulty seperating what functions are available to me. Evidently there's a few ...
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73 views

Multiple threads making call to precompiled library

I have been asked this question in an interview and I thought to take advice from you guys. Say I have a pre-compiled library which references to some function say "strtok". There is no source code ...
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1answer
137 views

Has pre-increment operators become that common? [closed]

Bit of background to explain the reasoning: I've been programming for a good while, but took a break between 2012 and 2014 for other stuff. Before that break, I would hardly ever hear about "++i", let ...
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104 views

Idiomatic C API with regards to pointers

I am trying to get a better understanding of how one would structure an API in C. I create a struct Person I have a init function that sets data on that struct I have multiple "helper" functions ...
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163 views

Understanding the concept of “arguments” and “parameters” in C language as explained in K&R The C Programming Language

In the third last paragraph at page number 26 of the ebook "The C Programming Language" the author(s) say, "We will generally use parameter for a variable named in the parenthesized list in a ...
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312 views

What kind of applications are built using C [closed]

I studied C programming about ten years ago, whiles in Uni,however I would like to pick it up again. I'm looking at developing secure applications that utilize cryptography. Would C be the right ...
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1answer
155 views

(almost) Pure C instead of C preprocessor [closed]

Why isn't (almost) pure C used instead of the C preprocessor? Sure I understand it would be a little more verbose. For example: #define PI 3.14159 If we had regular C as preprocessor language, the ...
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281 views

C Linked List Implementation Pointer vs. Pointer-to-Pointer Consistency

To get some practice in C, I'm writing some basic functions for operating on a linked list of ints. I started out with functions that accepted as a "list" a pointer to the head node. Now, I find ...
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usage of double pointers and n pointers?

I am familiar with basic C pointers. Just wanted to ask what is the actual use of double pointers or for that matter n pointer? #include<stdio.h> int main() { int n = 10 , *ptr , **ptr_ptr ; ...
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1answer
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Global variable in a Linux shared library

Suppose we have the following setup under Linux, .so library named "libcnt.so" and 3 user space apps: "app1", "app2", "app3". This library does 1 simple thing, it says to the app (app dynamically ...
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106 views

Looking for a certain datatype if it exists

I'm looking for the kind of a certain datatypes. The main idea of this datatype is to describe a productionline containing several steps. Each step should be represented as a "vertex" containing an ...
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908 views

Is it a good idea to const-qualify the fields of structure in C?

Consider the following program: #include <stdlib.h> #include <stdio.h> typedef struct S_s { const int _a; } S_t; S_t * create_S(void) { return calloc(sizeof(S_t), 1); } void ...
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122 views

How much warnings in C to enable?

This is a tiny project of about 2000LOC. It is being compiled with -Wall. Now, I tried adding -Wextra. Two things happened: Some minor but valid warnings popped up, e.g. Comparing signed with ...
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924 views

Algorithm for recursive evaluation of postfix expressions

I'm reading Sedgewick's book on algorithms in C and I'm looking for an algorithm to evaluate postfix expressions (addition and multiplication only) without using a stack. I tried to implement one but ...
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346 views

How small is the footprint of a small C compiler?

This week I could optimize using a reduced C library that allowed a drastic shrinkage in code size - from about 60 K to about 6 K and then we could load the code in the 8 K on-chip memory of an FPGA ...
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283 views

C/C++ in applications that do not concern performance [closed]

C is the best language (or maybe the single language) suitable for operating systems, drivers, embedded systems etc. For more complex domains like computer graphics C++ is a better choice. But these ...
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90 views

What's the simplest way to deal with events in C in this situation?

I'm writing a text-based game, in C. I want the game to handle NPCs movement and actions in the background, while the user is making his moves. I'd also use time-based events to tell the user when ...
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1answer
316 views

How static functions are better than Class Methods in Objective-C [closed]

I was going to through this post by Mattt Thompson in which he mentions that Static functions are nicer than shoe-horned class methods I just don't see any flaw with Class methods in ...
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1answer
112 views

Introducing function waypoints to protect device [closed]

Defining a magic pointer or counter inside a program / class and checking for a fixed value before executing critical commands is a way to generate a barrier against wrong execution. This check is ...
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170 views

Alternative to printing debug information to stdout\stderr [duplicate]

I currently have a long running application on an embedded Linux environment and all debug messages are currently being outputted to stdout using printf. This isn't ideal for special users who ...
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comparison of floating point numbers vs. comparsion of Integers in C [closed]

Does comparison of floating point numbers takes (considerably) longer time than comparison of Integers in C? I just wrote a C program of heap sort to sort floating point numbers. I am on ubuntu ...
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179 views

How can I handle this string concatenation in C in a reusable way

I've been writing a small C application that operates on files, and I've found that I have been copy+pasting this code around my functions: char fullpath[PATH_MAX]; fullpath[0] = '\0'; ...
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90 views

Should functions be prepared for overlapping buffers?

So I have a function in C like this: void crunch(const char *in, char *out, size_t inLen, size_t outLen) { //... } If the two buffers overlap, the function may mess up the input buffer as well, ...
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262 views

Is TCP message order still guaranteed when using async IO

Here the scenario I'm imagining. Two messages are transferred, both will require 2 packets each (I know you don't deal with packets directly with TCP, but on the IP level each message will consist of ...
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176 views

What are and how do (data-) types work?

What is a "variable"/data type? How does a compiler / interpreter handle types? My specific concern has to do with the different types in lower and higher level languages. For instance in Python, ...
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184 views

Perfomance of 8 bit operations on 64 bit architechture

I am usually a Python / Database programmer, and I am considering using C for a problem. I have a set of sequences, 8 characters long with 4 possible characters. My problem involves combining sets of ...
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816 views

Better design for a generic doubly linked list around which I plan to make different wrappers?

I am currently writing a C code for a doubly linked list(dll) around which I want to write wrapers for implementing stack, queues etc. instead of writing separate codes for all of them. I'll be ...
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Why nginx's http parser doesnt use regular expressions?

I see the http parser written by Igor Sysoev for nginx does not use regular expressions https://github.com/joyent/http-parser What could be the main reason for such design decision? I guess I could ...
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707 views

Giving a double type for sqrt library function in C

The C Programming Language by Ritchie says that: The library routine sqrt expects a double type and will produce nonsense if inadvertently handled something else. So if n is an integer, we can use ...
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1answer
229 views

Did I answer this correctly and concisely? [closed]

By email I just answered my brother who is learning computer programming that C++ and Java are more similar than C and C++ even though C++ is nearly a superset of C. Do you agree? AFAIK Stanley ...
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487 views

Which language is more suitable heavy file tasks?

I need to write a script (based on basic functions) to process /image/audio/video files. The process is mainly filesystem tasks and converts. The database of files has been stored by mysql. The script ...
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405 views

How to access an encrypted INI file from C on an embedded system with little RAM

I want to encrypt an INI file using a Delphi program on a Windows PC. Then I need to decrypt & access it in C on an embedded system with little RAM. I will do that once & fetch all info; I ...
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5answers
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Learning basic algorithms - better C or C++? [closed]

I'm studying fundamental algorithms (quicksort, mergesort, binary trees, etc..) and I'm going to re-code every algorithm by scratch to learn how they work. Should I code them in C or C++? I think with ...
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1answer
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Is it possible to call a Javascript function from C?

I'd like to find a way to call Javascript functions from C. Are there any language bindings available for this purpose? I'm trying to make a library of Javascript functions accessible from C. ...
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227 views

Tool to visualize values from variables during the execution of a program in C

I just need to see what is stored, in realtime, in some particular variables and struct used by an application written in C. I need something like the stack tracer that comes with the ADT plugins for ...
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164 views

Roadblock-confused about structure of program

I'm new to programming, and I'm working in C. I know that this is structured programming but if I use blocks, say for local variables: { int i; for(i=0; i<25; i++){ printf("testing...\n"); ...
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C programming in Windows 7 [closed]

Which is the best book and what are the best tools for C programming in Windows 7? Would using C in any way hinder me when it comes to using the Windows API as opposed to using C++ or C#? I would ...
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Organizing C++ Components [closed]

In my current company we've brought the discussion about how to organize most of our different C++ components considering the following requirements: There might be interdependencies between ...