C is a general-purpose computer programming language used for operating systems, games and other high performance work.
-7
votes
1answer
125 views
In the scope of C, what is the significance of '->'? [on hold]
I'm looking at old command-line cdplayer software for linux. This software was written in 2006, but won't compile with the latest GCC. I've taken to weeding through the errors and trying to patch ...
-1
votes
2answers
109 views
Is main() function better on top of all other functions? [on hold]
My college professor told me that main functions should be defined on top of other function definitions. We should use a forward declaration in order to accomplish this (we use C at that time). So yes,...
-4
votes
1answer
89 views
Is the followig code Compiler dependent or independent? [on hold]
Hi is the following C code snippet compiler dependent:
int c = 11;
int x = ++c + c++;
or compiler independent?
-3
votes
0answers
39 views
Help with SIMD algorithm implementation [on hold]
Hello guys i am really stack i need to implement matrix multiplication algorithm using SIMD but I don't know too much of c or c++ and i am having a bad time looking for a library with good ...
-3
votes
0answers
41 views
2d Array called into function. Why are 0's being inserted into the array while inside the function?
//prototype
int draw(int board[d][d], int d);
// draw the current state of the board. (Function call)
board[d][d] = draw(board, d);
//This is the function itself.
int draw(int board[...
2
votes
1answer
74 views
Explicitly mark unexported functions in a DLL?
When writing an unmanaged Win32 DLL that exports functions, it's not uncommon to have some functions, variables and/or classes that aren't meant to be exported and are only for internal use within the ...
1
vote
3answers
220 views
Can you pass a label as an argument, and have the function return to it?
So I would like to be able to call a function like this:
void func(1, 2, 3, (void*)label) // can return normal or to the labels
//some code
label:
//different code
Is it possible, and is it bad ...
0
votes
1answer
57 views
How to send a http request through a program developed in C?
As you read in the title, for example, i wanna login to my account in StackOverflow by sending the E-mail and password through a program developed in c language, so all what i have to do is to enter ...
4
votes
1answer
88 views
Do I need to declare a delay timer variable as volatile even if I access it from another module
This is a question more about using volatile to prevent optimization than about caching write/read of a variable. Particularly timer delay variables since I don't want to declare everything volatile ...
1
vote
0answers
21 views
Zeromq bidirectional asynchronous transmission?
I have a system which consists of two applications. Currently, two applications communicate using multiple zeromq publish/subscribe sockets generated for each specific type of transmission. Sockets ...
0
votes
0answers
46 views
Converting a 1D character array to a 2D array in random order.
I define my character array (9 items) as the following:
char arr[] = {'a', 'c', 'b', 'z', 'k', 'l', 'j', 'o', 'd'}
From this array, I would like to create a 3x3 array, in which the characters are ...
1
vote
3answers
133 views
Writing a #define for a common statement
Often when I program in C I write the expression for (int i = 0; i < j; i++).
I never wrote a macro or a define expression, but could I write a #define to simplify the above expression so that do ...
-5
votes
1answer
221 views
Why code in C instead of C++ [closed]
Why code in C? Isn't C++ basically C but with better features? Why do people still use C? Would it be easier to make a game with C or C++?
-4
votes
0answers
53 views
how to create a pipeline code which interfaces between Borland and visual studio platforms?
what pipeline program will act as a interface between visual basic C++ builder and Borland 5.0
they must fulfill these-
a C/C++ code which will be a pipeline method interfacing between C and C++ ...
1
vote
1answer
47 views
Need info on malloc trace
When I try the below code I am not clearly able to analyze malloc api internal calls.What I am not clear is about the system call mmap is called only once for 2 or more malloc calls.If I am assigning ...
48
votes
8answers
13k views
What happens to garbage in C++?
Java has an automatic GC that once in a while Stops The World, but takes care of garbage on a heap. Now C/C++ applications don't have these STW freezes, their memory usage doesn't grow infinitely ...
2
votes
1answer
106 views
Why do we use architecture-specific types in C
I think that the type names in Rust are much better than the ones in C. I'd choose f64 over double and u32 over unsigned int or uint_32t any day. Is there any reason (other than tradition) to use ...
1
vote
4answers
481 views
Why use a higher level language? [closed]
A question that gets asked a lot is "Why use low level languages if you can code in high level languages more easily (and often tersely)?". I think the answers are fairly straight forward here, being ...
0
votes
3answers
295 views
In C, why is NULL and 0 triggering an if statement
I have a function that is called by
myStruct *structName = myFunction(0);
The function looks like
myStruct *myfunction(int x)
{
if ( x == NULL)
{
return NULL;
}
/*rest of ...
4
votes
2answers
120 views
A question about implementing objects in a language written in C
I'm fairly new to programming (about four months learning), and have decided to mess about with an attempt at writing a language in C for both fun and practice, and am wondering how objects are ...
120
votes
15answers
29k views
Why do people use C if it is so dangerous?
I am considering learning C.
But why do people use C (or C++) if it can be used 'dangerously'?
By dangerous, I mean with pointers and other similar stuff.
Like the Stack Overflow question Why is ...
0
votes
1answer
167 views
How assembler coverts to machine code 1 and 0 [duplicate]
I know that assembler is the one which converts to machine code. So here in 8085 instruction set LDA has opcode "3A". My question is how assembler convert mnemonics to opcode and finally to machine ...
3
votes
2answers
135 views
Referential Transparency by using Zero References?
Referential Transparency is one of the corner stones of functional programming that allows us to apply equative reasoning to our code. However it does so at a cost to performance, by use of immutable ...
-5
votes
2answers
127 views
Why do I need these symbols to run a program? [closed]
#include <stdio.h>
int main() {
printf("Goodbye, World!");
return 0;
}
Why do I need #,<>, .h, and ()?
What are their purposes?
-2
votes
1answer
174 views
Calling an entire script (in C) from another script (in C++)?
I am a very inexperienced programmer, so apologies if this is a stupid question to be asking. And similarly, if anyone answering could assume that I know basically nothing at all and treat me like an ...
13
votes
1answer
391 views
What is the history for naming constants in all uppercase?
What is the history behind the convention of naming constants in all uppercase?
My intuition is that it started with the C preprocessor, where people developed a practice to name preprocessor macros ...
12
votes
4answers
3k views
Can a C struct behave like it had a function?
I use C and structs where a struct can have members but not functions. Assume for simplicity that I want to create a struct for strings that I name str and I want to be able to do str.replace(int i, ...
3
votes
3answers
282 views
Are global variables okay to use in asynchronous programs?
This may be a stupid question, sorry.
I've read about the drawbacks of global variables a lot on this site. I'm finally trying to increase my code quality for a large project that'll be reviewed by ...
3
votes
6answers
320 views
How efficient is malloc and how do implementations differ?
If I use malloc, does malloc always use the same algorithm regardless of what it is allocating or does it look at the data and select an appriopriate algorithm?
Can we make malloc faster or smarter ...
2
votes
1answer
37 views
Configuration related defines in public header?
Suppose you're building some library, C or C++ doesn't really matter for this question, IMO. The features (or implementation thereof) depend on capabilities of the target system.
A simple, probably ...
3
votes
2answers
135 views
memory allocation in C while calling function
I have a really basic question regarding how memory gets allocated in a code written in C.
Let's say that I have something like this:
int pointless(int a);
int main(){
int num1,num2;
num1=...
0
votes
0answers
28 views
Help me understand this flow for recursive function [duplicate]
This recursive function blows my mind a bit because it executes the recursive calls until it hits 1. It returns n, but afterwards it does the multiplication below it four times and returns the final ...
2
votes
3answers
78 views
Difference between passing by values/address and returning a values through functions?
According to a book I read you can pass variables from one function to another by passing by value/address. When you pass by address it will no longer preserve the variable if it is changed in a ...
0
votes
0answers
48 views
GUI - engine data exchange, design with C, getters or struct pointers passing?
Having quite big codebase and external libraries, in C application,
what would be pros and cons of two approaches (or suggest other):
(assume that there are NONE api provided calls for this)
Edit ...
0
votes
5answers
140 views
Range of values that can be stored in an integer type in C
C has family of integer types i.e {short, int, long, long long}. Any new programmer is likely to use int to represent integer variable in the application and since int type has 32 bit space with range ...
9
votes
1answer
157 views
Idiomatic wrapping of C++ template type API in C
I'm working on wrapping a C++ API which provides access to a data store (Hazelcast) in C functions, so that the data store can also be accessed from C-only code.
The Hazelcast C++ API for the Map ...
0
votes
1answer
31 views
DNS-SD implementation
I am trying to implement DNS-SD, and I understand how it works, but don't really understand the purpose, so I have a few questions about it.
Let us assume that we have two devices on local network, ...
8
votes
3answers
1k views
Why isn't C's most basic printing function named `print` instead of `printf`? [duplicate]
AFAIK, C does not have a print function. The most basic we can get is printf. So, is there a reason why this function is not simply named print, instead of printf?
Note that this question is about ...
14
votes
3answers
275 views
Supporting development for older OS
I am maintaining a large portion of legacy code, written in C. This code was initially written to be comiled against Windows 3 for Workgroups, and later a version for NT was created. This legacy ...
1
vote
2answers
176 views
What are microcontrollers programmed in most in industry? C or Assembly? [closed]
So recently in school we have started programming klm25z boards using ARM Assembly. I was wondering if in most industry jobs, microcontrollers are really programmed in assembly over C. It seems to ...
1
vote
1answer
156 views
Unit testing C code?
I learnt about the check testing framework today that seems good. This far I've scripted tests that uses valgrind so that the tests both display output from the tests and from valgrind. Is there a ...
2
votes
1answer
212 views
When to malloc and free?
Valgrind does not report a memory leak during my actual usage, only during my scripted test that I scripted with a shell script to test my own shell. I found that I didn't have to use malloc every ...
2
votes
0answers
103 views
What are the benefits of an input/output component design?
For the company I work at, all of our projects,
including a new one started last year, are written in C89.
We write for vxWorks (a real time embedded operation system).
Our software runs multi-...
-1
votes
1answer
61 views
During fork system call which execute first parent or child
As i am executing a one pipe example pgm from libc.pdf,I noticed that the parent process first completed then only child process completed.From my knowledged about os the child process must complete ...
-1
votes
2answers
67 views
Run C program in debug mode (without debugger)
If I want my program to be able to run in debug mode, is it a good idea to make it accept a flag such as -D=DEBUG when I run the program? I currently have a DEBUG variable in a .h file but that I can'...
2
votes
2answers
109 views
algorithm for shell language interpreter to find if a char is between quotes
Assume we have a string s (a C char *) that is a program in a language L. I want to parse L and know the following from the specification
The following characters must be quoted if they are to ...
-2
votes
1answer
154 views
For loop and recursion for a new shell in C [closed]
I code a new shell in C, that could be done in several ways: Flex/bison, finite state machine, abstract syntax tree or just a tokenizer in C. Now I've written a for-loop that changes the condition of ...
2
votes
1answer
169 views
Is it impossible to write proper, const correct callbacks in C?
In C, a non const object implicitly converts, without warning, to its const counterpart, so you can write a function, and call it as:
void foo( const char *p );
char bar[] = "bar";
foo( bar );
...
1
vote
1answer
147 views
Does having so many macros (#define) increase compilation time due to prolonged pre-processing?
In a very simplistic way, I understand:
"Compilation" = "Pre-processing" + "Parsing" + "Linking" + "Executable"
All the macros and other such pre-processing directives are taken care at the "Pre-...
4
votes
4answers
340 views
Coding style: Binary logic or multiple if()s?
Something that often comes up in code reviews is the structure of the code, particularly related to the use of control structures, where individuals can be fairly opinionated on what is "right" and ...
