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

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2
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2answers
169 views

What is the point of designing Lua C APIs?

I am a newbie of Lua. After studying some Lua C APIs examples, I am a little confused. I can see the Lua C API is used for processing Lua scripts: ...... lua_State *L = luaL_newstate(); ...
1
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2answers
152 views

Complex iterators in C

note: this was originally asked on SO. Part of my current project involves iterating over sequences that don't necessarily exist. For example, I have something similar to a relational database in ...
16
votes
2answers
417 views

Has variable width types been replaced by fixed types in modern C?

I came across an interesting point today in a review over on Code Review. @Veedrac recommened in this answer that variable size types (e.g. int and long) be replaced with fixed size types like ...
3
votes
3answers
203 views

How to maintain modularity in C?

I am writing C code with multiple modules like LCD display, flash memory, and GSM module etc. The project consists of thousands of lines of code, in different files. The behavior of the system can be ...
6
votes
2answers
2k views

What is the difference between function() and function(void)?

I have heard that it is a good practice to write functions that do not receive anything as a parameter like this: int func(void); But I hear that the right way to express that is like this: int ...
-1
votes
2answers
72 views

If I #include a file, do I need to have a valid path to any headers #included in the included file [closed]

For example, if I have created a library, libcommon, which uses some other custom, but widely used library in a specific field (some_other), like this: libcommon.h #ifndef LIBCOMMON_H #define ...
26
votes
10answers
7k views

What is the “type” of data that pointers hold in the C language?

I know that pointers hold addresses. I know that pointers' types are "generally" known based on the "type" of data they point to. But, pointers are still variables and the addresses they hold must ...
1
vote
0answers
350 views

Why C doesn't have better notation for pointers? [duplicate]

The * symbol is used for three different purposes multiplication Pointer declaration Pointer dereferencing. Why designers of C kept this notation? In other words, wouldn't it be nice if there ...
2
votes
1answer
209 views

C Module - Where to put prototypes and definitions that do not belong to the public interface?

Since I am mainly an Electrical Engineer, forgive me if I am somewhat off with some terminology. I am currently programming a display driver/interface module. And like so many times before, I have ...
9
votes
8answers
2k views

What stops C from being compiled/interpreted/JIT'ed?

Java is often praised for its amazing portability, which I presume is because of the JVM. My question is what stops C from being being compiled/interpreted/JIT'ed.., if so, C can also be write once ...
38
votes
6answers
4k views

How to think as a C programmer after biased with OOP language? [closed]

Previously, I've only used Object Oriented Programming languages (C++, Ruby, Python, PHP), and am now learning C. I'm finding it difficult to figure out the proper way to do things in a language with ...
5
votes
1answer
323 views

Kth selection routine - Floyd Algorithm 489

I have recently come across a promising Kth selection routine that reportedly outperforms quickselect the Floyd, Rivest Select routine. This Wikipedia article provides a pseudocode version which I ...
0
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0answers
39 views

Synchronizing content between web-based app and game server

I have a MUD server, written in C, that I'm trying to move from file-based storage to MongoDB. Eventually, I'd like to offload administration of game content and settings to a web console, written in ...
5
votes
2answers
139 views

What is a reasonable level of detail for a style guide? [closed]

We are developing embedded software for an automotive product in ANSI-C in a large team. Yesterday, in our regular code review, we had a general discussion about the style of our code. We have a ...
2
votes
2answers
302 views

What are the benefits of a device driver when I can access the I/O registers directly?

I was interested in what modern, C-based, Linux device driver development looked like, and so I took a good gander at this excellent article. I didn't read every single line, but perused the majority ...
2
votes
2answers
214 views

Compiling and deploying a C program to an MCU running an RTOS

Please note: Even though I'm specifically talking about an RTOS called Embox here, and even though I'm talking about AVR/ARm, I think this question can be answered by anybody whose ever done a fair ...
2
votes
1answer
90 views

Compiling and deploying RTOS to an MCU

Please note: Even though I'm specifically talking about an RTOS called Embox here, and even though I'm talking about AVR/ARm, I think this question can be answered by anybody whose ever done a fair ...
3
votes
2answers
719 views

Benefits of RTOS vs Bare Metal for MCU Programming?

Please note: This question specifically mentions two RTOSes but is more generic and can probably be answered by anybody who has written C code for embedded RTOSes before, and had their software run ...
0
votes
0answers
102 views

GMP Core Dump while using mpz_clear in C

I'm working on a prime factorization program written in C using the GMP library through cygwin. The algorithm that I have now works fine, but has memory leaks from not using the mpz_clear function on ...
51
votes
8answers
7k views

Why does C provide language 'bindings' where C++ falls short?

I recently was wondering when to use C over C++, and vice versa? Fortunately someone already beat me to it and although it took a while, I was able to digest all the answers and comments to that ...
0
votes
0answers
406 views

Best way to signal all child processes to terminate using C

I have been assigned the task of designing a simple web server using C in my UNIX & C class. The webserver listens and forks when a successful connection is made so that multiple clients may be ...
2
votes
0answers
197 views

Have any C compilers ever *defined* `unsigned short x=-3; x*=x;` to yield anything other than 9

In a C implementation where int can hold all values of type unsigned short, standard integer promotion rules dictate that given the code: unsigned short x=(USHORT_MAX+1)-3; // Or just -3 x*=x; a ...
-2
votes
1answer
194 views

Question about switch-case statement [closed]

What happens, and does code work properly if we write switch-case structure like this, why its not good to write code like this? I'm porting some firmware and have switch-case statement interrupted ...
1
vote
1answer
95 views

Equivalent translation of Asynchronous behaviour in C

As a follow-up to my other question, if one were to build a general-purpose translator from a language that has support (be it with an external library or otherwise) for asynchronous behaviour to a ...
3
votes
1answer
676 views

Implementation of Asynchronous function call in C

I took it upon myself recently to work towards making a general-purpose Translator to automatically translate js programs into C, but I got stuck when thinking of asynchronous behaviour. Using ANSI / ...
6
votes
8answers
1k views

Structuring Procedural vs OO code

I have spent the vast majority of my programming career using Java and very OO based C++. I am really interested in learning to think more procedurally, so I have been starting to do some practice ...
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votes
1answer
83 views

how integer type can handle text stream (getchar()) in C? [closed]

While going through C programming by Ritchie and kernighan, I came across the following code. #include<stdio.h> int main() { int t; t = getchar(); while ((t=getchar()) != EOF) { ...
3
votes
2answers
746 views

How does printf write to stdout? [closed]

I've been looking for an answer to this for a couple days, and all of the results I've come up with are about how printf accepts an arbitrary number of arguments. How does printf write to stdout? ...
-1
votes
2answers
123 views

In C is it possible to change http requests to https [closed]

Long story short I've got this package that currently has a security risk where credentials are sent over http and I need to convert them to https but I currently lack the knowledge to do so. Could ...
1
vote
5answers
4k views

How to share memory between applications written in C/C++

I'm going through a program written in C/C++ for control in robotics. Basically, three different programs run at the same time, and they communicate via shared memory. Google-ling around I found ...
20
votes
8answers
1k views

Is directly using Make considered obsolete? [closed]

So I have been coming across many comments/posts/etc regarding creating makefiles directly, and how it is a silly thing to do in 2015. I am aware of tools such as CMake, and I actually use CMake quite ...
0
votes
0answers
91 views

Abstract Web API from validation and configuration management in embedded system

Im working with embedded Linux for a router. There is a web GUI for the user to configure router options. When user fill a web form this is submitted to a web server function that is responsible of ...
0
votes
1answer
159 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 ...
2
votes
1answer
274 views

How can C++ make it possible to use dynamic container classes even in embedded systems?

How can C++ make it possible to use dynamic container classes even in embedded systems? Background info: I've been working with PIC (C) and AVR (C++) processors and at the moment (PIC C) I'm ...
0
votes
2answers
139 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 ...
1
vote
3answers
426 views

Alternative to goto-statement in this case? [duplicate]

Currently I am using gotos for closing handles and general cleanup if an error occurs. Since I don't want to nest all the ifs and a function for cleanup would require a return besides the cleanup(); ...
2
votes
2answers
132 views

Function naming design in a C Library

I'm writing a C (c99) library that operates on strings. I'm having a design problem writing functions that will perform in different modes. For example; the Find function can search for: the ...
-3
votes
1answer
163 views

Passing Parameters to pthread_create [closed]

I have a structure named graph. graph *G; Now I create memory of size of structure using malloc and the start pointer is stored in pointer G. G = (graph*)malloc(sizeof(graph)); My question is ...
5
votes
2answers
630 views

Should I always return an error code from C functions?

I have the following code in many places in a large application: if (datastruct.data_ok && cur_time > datastruct.start_time && cur_time < datastruct.end_time) { ...
0
votes
0answers
250 views

Writing Z80 table based assembler/disassembler

I have a long-term project: DIY computer with various processors. One of my wishes not only make hardware, but software too. So I started from assembler/disassembler for Linux, though there is a lot ...
0
votes
1answer
147 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 ...
17
votes
9answers
3k views

Can you “stop” a C program from being reverse engineered? [duplicate]

I'm sure that many of the middle to high level languages can be reverse engineered. But if a C program can be reverse-engineered, and turned back into editable source code, how do I discourage such a ...
2
votes
3answers
286 views

Will C compiler attach the whole object code of the header file?

When you compile a C source code does the compiler convert the whole header file to object code or just the functions of the header file you use? Like for example, in the header file #include ...
1
vote
2answers
181 views

In C, what is an unconditional jump?

I have to fill out some documentation regarding a C project i worked on. One topic is whether I used "unconditional jumps". As far as I know, a "break" statement counts as a jump. And I have a few of ...
2
votes
2answers
699 views

Returning multiple values from a c function using pointers; style of parameter list

What is good programming style for writing C-language functions and function calls to functions which return pointers? For example, if I have a function my_function which return two integers through ...
1
vote
0answers
90 views

How to use an enumeration type, when the values are not known at first?

We have a project, that consists of a cluster of C source code, a C library and a C++ library. The C++ library is dependent only upon the C library, or at least that is what I am trying to achieve. ...
0
votes
2answers
94 views

forking but not exiting

It is normal for the child in a fork() to call exec() or _exit(). Are there any realistic scenarios where the child might return from the function that called fork() instead? void foo() { pid_t ...
13
votes
2answers
743 views

Java has the JVM, what does C have?

I know that C has a compiler but what determines execution performance? For example in an if else block, what if the code just had all ifs instead of if elses, what determines that all the ifs will ...
2
votes
2answers
380 views

Should I use multiple state machines for a layered protocol?

When implementing a layered communications protocol are layers commonly implemented as state machines? I have an implementation of PMBus I am currently working on for an embedded device. I have a ...
0
votes
2answers
128 views

Trouble understanding simple recursion in c [duplicate]

My function: int num(int x) { if(x>0) num(x-1); else return 0; printf("%d",x); } This function takes a input x and prints the numbers from 1 upto x.I can't seem to ...