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

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using flat file vs sqlite db for frequent data grabbing in a cron job

I have some automated task to be done using certain types of logs generated on the server end of each day. Log files contains specific machine identification "MAC" that is to be re-written in to ...
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1answer
134 views

How to implement an algorithm out-of-core?

I want to implement a parallel clustering algorithm "out-of-core" in CUDA. My CPU has 12GB of RAM and GPU has 4GB of it. What I want is that the entire dataset should be on the disk, and I can pick ...
5
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1answer
161 views

At ping, why do we have to do array copying instead of passing on the source array that the client sent to us?

So I have been googling about this OpenSSL heart-bleed thing and somehow sees that it is caused by the heartbeat extension which requires client to ping the server to show its aliveness and it all ...
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2answers
102 views

Advice for simple communication protocol (iPod and Arduino)

I connected iPod with Arduino using serial (UART) connection. Arduino sends 0-1023 number (so it's two bytes) as it's samples light sensor value. I'm asking about advice about simple and reliable ...
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2answers
157 views

How to manage memory in C interface for C++ implementation considering c++11?

I have a library implemented in C++ which has a C interface. This C interface is, for all intents and purposes, the only way to use this library. C++11 seems to discourage the use of raw pointers but ...
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3answers
68 views

Best and safest API for a function which fills a buffer with variable-length data

I have a function which receives a buffer and returns some data in the buffer. The data can be smaller than the buffer capacity. Which is the best and safest API for this? int fn(void *buffer, ...
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2answers
57 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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2answers
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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5answers
105 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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2answers
237 views

Are (C) object files created with different compilers binary-compatible?

I understand that C++ compilers are not compatible with each other. However, I was unable to find anything on this topic for C in particular. I know that the C standard leaves a lot of room for ...
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1answer
91 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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3answers
145 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
231 views

Representing a deck of cards in C (not C++)

So far my best ideas have been as fallows A) Represent a "card" in one structure and have a "deck" in another a deck being an array of 52 cards and a card being 2 chars one for and rank one for suit. ...
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4answers
247 views

How do you call one program from another?

What I'm wondering is how running programs communicate with each other, and if someone could post some sample code for how to do this, so I can try it out myself, just for educational purposes. For ...
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0answers
93 views

What is the underlying mechanism behind va_list and where is it defined?

http://www.cplusplus.com/reference/cstdarg/va_list/ According to the above link, va_list is an argument or parameter used in some macros - va_start, va_arg, va_end. These macros are present in the ...
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1answer
179 views

What is this programming style? “Monoid-ic”?

In a moderately old blog post, Conal Elliot makes an interesting (if less than serious) argument that C is a purely functional language, by drawing a parallel between the combination of the C ...
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0answers
113 views

How to extract the active code path from a complex algorithm

I have been puzzled lately by an intruiging idea. I wonder if there is a (known) method to extract the executed source code from a large complex algorithm. I will try to elaborate this question: ...
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1answer
115 views

Global variable vs. local-static variable for storing state

I am writing an application for my graduation coursework, in C, using GTK+ UI library. Sometimes I ask for user input, which I need to save for later use. The doubt comes on how to store this data. I ...
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2answers
215 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 ...
3
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2answers
249 views

Speed difference between VM-based and compiled code [closed]

Not so long ago I was told by a senior academic that, these days, VM-based code could run nearly as fast as compiled code, but my own experience is that compiled code runs several orders of time ...
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2answers
230 views

Creation of an Assembler [closed]

I've always been interested in how programming languages are created, so for the past 8 months I've been researching, practicing and more about the creation of compilers. I've been able to quite ...
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0answers
110 views

Problem with Vi editor using PuTTy [closed]

For my computer science class for intro to c/c++ we are using the PuTTy client to work with Vi. During one of my assignments I was in the other room and apparently my cat jumped up on my laptop and ...
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3answers
366 views

How to teach pointers to beginners in C? [closed]

I'll hold a little presentation about C-Pointers in a small group of people with beginners programming skills, with no CS background. Just people who would like to learn something about coding and ...
2
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1answer
138 views

OOP in C: which of these two approaches is closer to a cannonical solution? [closed]

Here are the two approaches to writing OOP (as in "we have objects and we can instantiate any number of them, each having it's own private data"). The language is C and the platform is embedded ...
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3answers
197 views

How do I maintain consistency between hard-coded values in different files?

I have a C source file and another (non-code) file in a project which contain the same hard-coded value. Ideally, the value would be specified in only one location and be copied to the other location ...
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3answers
288 views

Choice between 1-dimensional and 2-dimensional array

I'm implementing the Chessboard class to represent the chessboard. I've to implement the transformations (reflections and rotations) on the chess board possible. The possible transformations includes ...
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5answers
339 views

How to make it obvious that a function is being accessed from the outside?

This is a C specific question. I am trying to keep everything possible inside the translation unit boundaries, exposing only a few functions through the .h file. That is, I am giving static linkage to ...
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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
271 views

How do we go from assembly to machine code(code generation) [closed]

I know this is abstract as it's all about signals and switch - (electronics) - underneath, but is there a easy way to visualize the step between assembling code to machine code. For example if you ...
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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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1answer
219 views

Next power of 2 for a number (in search for better “bit-twiddling” way)

I just wonder if there exists better (i.e. faster?) way to get the next power of 2 for a given number than the following one (maybe some better sort of "bit-twiddling" hack is possible?) ... static ...
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3answers
176 views

C API in C++ with RAII, two alternatives to implement error handling (Exceptions)

I have an API written in C, which produces a result by returning a pointer to allocated memory. For using it with C++ (C++11) I've wrapped the function calls in objects, which keep the result in a ...
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6answers
534 views

Coming from high-level to C [closed]

I have a web background that grants me basic understanding over programming. Some older kids wouldn't even call that programming knowledge ("any moron can do PHP/Python/Ruby"), I guess, but let's not ...
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1answer
169 views

Is learning different programming languages from different categories good? [closed]

I have read some posts regarding learning different programming languages or not. Most of the answers indicate that learning more than one programming language increase our horizon as a programmer and ...
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1answer
82 views

Creating a window to draw pixels in [closed]

I'm creating a fictional architecture and other fictional components for this computer/emulator. I'm facing an issue, this being the virtual display. I need to be able to create a Window in which my ...
3
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1answer
141 views

How can Lisp produce an iterative process from a recursive procedure?

I am starting to learn Lisp, using the SICP book. The authors mention that a procedure (i.e. function) can be recursive or iterative. Additionally, the process those procedures will generate will also ...
2
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1answer
102 views

Is the result of strcmp the same on all machines and compilers?

Code: #include <stdio.h> #include <stdlib.h> #include <string.h> int main() { int n = strcmp("hello","help"); printf("%d\n", n ) ; return 0; } Result: -1 Does ...
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0answers
52 views

wrap mysql API for gui use

Some time ago now, I've written a command-line tool, that connects to MySQL, and through a series of commands, does all sorts of good stuff. It was originally intended to be used by myself and, ...
3
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2answers
238 views

using unsigned integers in c, c++

I have a very simple question that baffles me for a long time. I am dealing with networks and databases so a lot of data I am dealing with are 32-bit and 64-bit counters (unsigned), 32-bit and 64-bit ...
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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, ...
0
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1answer
142 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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1answer
103 views

A Server sending data to be processed to clients [closed]

About a year ago I had an idea in mind which was using my friends computers to help me process my data, so I programmed a socket server application with boost::asio, and gave the client part of it to ...
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3answers
148 views

Question about moving to embedded systems [closed]

I currently work as a .net developer and have coming up to 3 years experience in the industry as well as a degree in computer science specifically software engineering (I know that means nothing but ...
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1answer
194 views

Is using non-standard single-line comments fine in C? [closed]

I noticed Visual C++ 2010 (my current environment) and XCode both allow non-standard single-line comments in my C programs. Since these are both my target platforms, I assume it's fine to use it? VC++ ...
0
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3answers
415 views

Why are there so few comments in C/C++ code? [closed]

I'm a web developer primarily, and I've been learning C/C++ and trying to get involved in some open source projects. Something I find very unusual is the lack of comments in C/C++ source code (I've ...
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2answers
258 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 ...
9
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3answers
542 views

How should I mark types in C and C++ programs?

In this answer of mine, I used _t at end of types, which ended at best, controversial. This is the practice I use in my current projects. typedef struct { int x; int y; } point_t; This was ...
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3answers
307 views

Can only integers be stored as register variables?

I am confused about this: what type of data can we store in register variables? I guess logically we can store any kind of data as register variables because they are variables, but really I am ...
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2answers
299 views

Drawback of mixing C++ code with C for performance purposes

Often you can see answers like “Avoid using C libraries in your C++ code“ or “This can be rewritten using STD/Boost in pure C++“. I understand C++ produces more maintainable code and has many ...