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

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Writing generic code when your target is a C compiler

I need to write some algorithms for a PIC micro controller. AFAIK, the official tools support either assembler or a subset of C. My goal is to write the algorithms in a generic and reusable way ...
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1answer
579 views

Having trouble understanding recursion [duplicate]

I have just started learning about recursion but I'm having a hard time understanding it. Please would you recommend any links or books that explain recursion in detail.
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4answers
479 views

How does using #define for loop and condition bounds in C increase security?

My program uses the following define statements: #define LOWEST_PATIENT_ID 10000 #define HIGHEST_PATIENT_ID 99999 #define LOWEST_CRITICAL_STATUS 1 #define HIGHEST_CRITICAL_STATUS 100 used in this ...
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5answers
107 views

What conclusion to be drawn from no difference in generated assembly from 2 rather different programs?

I might not have had a counterexample when I got the reply "A pointer is just an address, what's the difficulty?" but I didn't really buy such a simple explanation and at assembly code it's not ...
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140 views

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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760 views

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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5answers
843 views

New to Programming/objective c

I've recently started to work on some iPhone apps, starting from a base where I had essentially no programming experience (I studied Maths & had very few programming modules) I worked my way ...
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3answers
72 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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3answers
171 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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3answers
131 views

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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2answers
58 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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135 views

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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2answers
116 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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3answers
400 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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3answers
278 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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1answer
128 views

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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3answers
190 views

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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3answers
147 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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2answers
81 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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1answer
140 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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2answers
128 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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2answers
216 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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2answers
174 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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1answer
227 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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2answers
352 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
218 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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3answers
350 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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2answers
304 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
969 views

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
682 views

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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1answer
160 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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3answers
160 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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1answer
3k views

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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72 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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1answer
94 views

Algorithm for base-conversion in C?

I put in this code which does what it's supposed to do, but perhaps there is a better or more general approach? I'm converting a 4-digit base 10 number e.g. "11" to base 16 e.g. "17" (which gets ...
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2answers
223 views

Shared source file between two parts of project [closed]

I have the following sort of directory structure: part1 build src part2 build src Now I have a header file that I would like to include in both parts of these projects, it will ...
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2answers
283 views

Dynamic initialization, how does it work?

I have a question regarding dynamic initialization. Example code void main() { int a = 100; //Statement1 //Statement2 ... float b = 6.32987; //StatementA ... return; } The StatementA allocates ...
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1answer
116 views

The keyword const and the linker file

If I declare in a header file, for example, extern unsigned long * Ptr; and the value of this pointer Ptr in the linker file. Will this adrress be 'constant'? Can I change its value ?
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1answer
171 views

Example(s) of “A subscript ([ ]) expression that does not evaluate to an array” in C

I think I have never seen a [] that doesn't mean array in C. Background: I was reading about l-values and r-values here: http://msdn.microsoft.com/en-us/library/bkbs2cds.aspx and there it says so. I ...
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2answers
539 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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4answers
912 views

How should I go about developing some basic C/C++ knowledge so that I can grok the concepts written in some Classic software programming books? [closed]

I know Java and JavaScript pretty well. I have never really worked on C/C++. But at this stage of my career I feel that the fact that I do not have adequate knowledge on C/C++ syntax(especially ...
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1answer
601 views

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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3answers
92 views

How to manage intermediate outputs efficiently?

I am implementing a C preprocessor in C... I have the three functions: trigraph replacing function Line splicing function comment removing function However these functions work separately on ...
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2answers
484 views

How to practice programming? [closed]

I've been a PHP developer for 5 years now. Before I started working in that field, I've been practicing at home. I've created my own CMS, so I could actually show some of my code to the potential ...
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2answers
532 views

tcp retransmission queue

I'm trying to understand how tcp retransmission queue works so I can implement it in my application that uses TCAP over SCTP. What I understood from the TCP queue is that every message is saved in ...
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2answers
584 views

Equivalent of common IntelliJ actions in vim for C development [closed]

I am attempting to move from IntelliJ IDEA to vim, primarily for C development. What are the equivalent of the following common IntelliJ features/tasks in vim (and what plugin is required if any)? ...
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2answers
324 views

Asp.net certification [closed]

I want to get my certification in .NET, which certification is the best for me? For the past 8 months I have been working in the .NET 3.5 and 4.0 frameworks. How can I grow myself by appearing this ...
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1answer
144 views

distributed computing with remote hetrogenous machines

The way i am doing it now is using boost::asio TCP sockets handling everything manually with a main server that orchestrates the processes between the available machines, but the number of machines ...
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2answers
341 views

What is the exact syntax of inline?

CASE 1 (Definition and declaration in same source file) Suppose both my prototype and definition of global function is in .cpp file. Where should I write inline keyword to make compiler know? In ...
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1answer
395 views

Multi-threaded server

I have written a server/client program in which I am using 2 threads : One to recieve data continously and Other to send data as the user writes it on screen Problem: I have created the threads ...