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

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Can someone clarify strings for me in the C programming language

Hey guys so I'll cut this short. A few weeks ago I started learning the programming language C. I have knowledge in web technologies like HMTL/CSS, Javscript, PHP, and basic server administration. ...
4
votes
3answers
134 views

Safety-critical software and optimising compilers

I'm reading some internal documentation for code developed to the MISRA C guidelines, and I see that in compiler flags section of the documentation there is a note to compile with optimisation off ...
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0answers
4 views

Linux C raw socket TCP handsake [migrated]

I'm trying to create a TCP connection using raw sockets in C (on a Debian system) but I'm having a hard time getting it working. It will send a packet but I dont get any response from the server. I ...
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0answers
27 views

What are some best practices for converting a codebase from Matlab to C using MATLAB Coder?

I am starting a project to convert a medium size Matlab codebase (~100 files, total of ~10K LOC) into C/C++. (That is, the end product needs to be runnable without Matlab.) I have been reading ...
3
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1answer
44 views

Bottleneck performance in ECS

I've been looking into building an entity-component-system. Basically, an entity is just an id wrapped around a struct, components are data belonging to that entity(and reference said id), and systems ...
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5answers
2k views

Why is *declaration* of data and functions necessary in C language, when the definition is written at the end of the source code?

Consider the following "C" code: #include<stdio.h> main() { printf("func:%d",Func_i()); } Func_i() { int i=3; return i; } Func_i() is defined at the end of the source code and ...
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2answers
220 views

Disadvantages of Pointers [on hold]

I was wondering why pointers are not included in modern languages now-a-days. I already did research on this on internet, and found out few theories/reasons: Memory leakage is the biggest concern ...
81
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6answers
11k views

Is every language written in C?

It may sound stupid but, sometimes while programming on different languages, this thought comes to my mind. Is each and every language written in C language? Is C language mother/father of all ...
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2answers
155 views

Why define struct in variable?

Consider the following program: Many people when they want to use a struct, they create a new variable as: struct structureName variableName While it works when you just define it as: ...
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votes
0answers
58 views

Replace tabs with spaces in C [on hold]

i want to replace tabs with spaces but i didn't get it. I have an file pointer which i give into the function and there are some \t and i want to replace them with as many spaces as needed. For ...
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votes
0answers
60 views

C application vs C++ application [on hold]

What are a real life application that is based on C language rather than C++? Why is it using C and not C++ since they are almost the same? Do you think we can convert that application to C++? And how ...
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1answer
35 views

How can this allocation of bi-dimensional arrays work?

I was seeing this post on StackOverflow and saw a new way (at least for me) to define a two dimensional array of 5x5, it works well, but I feel I don't understand what is going on in the background. ...
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0answers
58 views

Is the time complexity of this code snippet O(n)? [migrated]

struct lists * list_depth[ht]; for(int i=0; i<ht; i++) list_depth[i]=NULL; insert_to_list(&list_depth[0], root); for( int i = 1; i < ht; i++ ) { struct lists * temp = ...
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votes
0answers
46 views

Custom code folding in Eclipse [on hold]

For those who use Eclipse and are working primarily in Java, there is a custom folding plugin coffee script. It is old but still works. However, C/C++ users are left without code folding ...
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0answers
34 views

Find the number of increasing Sequence of length K [on hold]

Let we are giving a Array we have to find the number of increasing sequence of length K. 1 2 3 1 1 For the first window of [1, 2, 3], there are 3 non-decreasing subranges so the answer is 3. For ...
-1
votes
1answer
98 views

Is there a practical use case for 5 stars (pointer to a pointer to …) [closed]

I know of practical use cases of 3 stars (e.g. char*** test), I've seen one of 4 stars, but is there a practical use case for 5 stars that couldn't be made (elegantly) using less?
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3answers
121 views

Use of for loop conditional statement unrelated to iterating variable

Is it considered decent form to write code like this: int done = 0; for (x = 0; !done; x++) { ... something involving 'x', that might end early ... if (!(x < max)) done = 1; } ...
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0answers
56 views

Are there any tools that calculate the stability metrics for a C code base? [closed]

I am looking for static analysis tools which calculate the (in)stability* of various modules in a C code base; similar to how a tool like CCCC calculates the McCabe complexity of a code base. * ...
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3answers
73 views

Question about multidimensional arrays

I was wondering something about the multidimensional arrays and then I got a doubt about a concept, specifically about their representation on memory. For example, an array can be defined as follows. ...
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2answers
209 views

Searching algorithm used in switch statement

What is the searching algorithm used in switch statement in C language? If the cases are not in order still it searches proper case which means it is not a binary search algorithm, can anybody ...
0
votes
1answer
106 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 ...
-2
votes
1answer
82 views

Printing value of atoi of an array - what does the number mean? [closed]

Simple question, below is my code. The number my compiler returns is 4219296. My question is: why? What is my code doing here? #include <stdio.h> int array[]; int main() { atoi(array); ...
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votes
3answers
1k views

Why do we have to mention the data type of the variable in C

Usually in C, we have to tell the computer the type of data in variable declaration. E.g. in the following program, I want to print the sum of two floating point numbers X and Y. ...
0
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0answers
17 views

Is `\n` necessary to be given to `printf()` in C [migrated]

I am reading the book "The C Programming Language" by Brian Kernighan and Dennis Ritchie. In the first article they say that one must use \n in the printf() argument, otherwise the C compile will ...
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0answers
24 views

C - meaning of non zero adresses in nullspace [migrated]

This is a linked list queue implementation. This is my program int size(QueuePtr q) { QueuePtr temp = q->next; int size = 0; while(temp) { size++; temp ...
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0answers
6 views

Matrix Multiplication question [migrated]

So I'm trying to write a C function to calculate the multiplication of two arrays but I am a little bit stuck. double ** matrixMultiply(double **A, int nRowsOfA, int nColsOfA, double **B, int ...
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0answers
5 views

Loop in system call C program [migrated]

I want to call the function wget in a loop in ubuntu, how can I do it? This is what I did, but it didn't work. for (i = 1; i < 500; ++i) { system("wget -O page%i 'http://www.asdf.com/?=%i'", ...
3
votes
4answers
305 views

Why do we have to tell printf() the type of data in C?

Let's consider this C code: #include <stdio.h> main() { int x=5; printf("x is "); printf("%d",5); } In this, when we wrote int x=5; we told the computer that x is an integer. The ...
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votes
0answers
22 views

Get defines dynamically for messages [migrated]

In this following code, i want to use predefined message for my errors_manager function, with the macro CALL_MSG(). but when i use an variable, i can't get the content of the variable ! err = ILLOPS ...
-2
votes
2answers
68 views

Using a global struct with pthreads in C [closed]

I'm trying to simulate clients going into a bank and being served by tellers over a period of time. I am using a thread to determine if a client came into the bank via an arrival rate and am using ...
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votes
3answers
79 views

Some tips on creating programs in C? [closed]

So I'm currently in my first year in university studying electrical engineering. I'm taking a intro to C course, and I'll say it now, I'm not sure if I'm going to be able to pass the exam. Even with ...
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0answers
3 views

convert string to integer does not work for nagative case C programming [migrated]

I have some homework in which the first step is converting the input string into an integer. Example when I input "1 2 3 4" then its output is : 1 2 3 4, or input is: a1b3c 4 then output is 1 3 4. ...
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0answers
5 views

Complex Data Type in C Producing Trouble in Algorithm [migrated]

I'm trying to perform a calculation which involves the following C-function: long double complex* tridiag_thomas(long double complex *a, long double complex *b, long double complex *c, long double ...
2
votes
1answer
113 views

Exceptions in ANSI C

Would it be possible to implement exception mechanism in pure ANSI C similar to the one used in popular OOP languages (with familiar try-catch-finally clauses)? If yes then how? I'm especially ...
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0answers
40 views

type name for state machine state (as opposed to other state variables)

I need to create a typedef for a state machine state, e.g. enum ToasterStateMachineState { TSM_READY, TSM_TOASTING, TSM_DONE }; But ToasterStateMachineState seems verbose and redundant; is ...
4
votes
1answer
108 views

What is grouping?

In the introduction to K&R there is the following text: Similarly, C offers only straightforward, single-thread control flow: tests, loops, grouping, and subprograms, but not ...
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3answers
135 views

Socket Connecting to Large number of IPs

I have a text file of ~600 CIDR notation IP blocks which, when expanded, amount to ~17.5M IP addresses. I need to socket connect to each one. If it connects, I add it to a "live" list, if it returns ...
0
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0answers
57 views

Does multiple Bloom filters make sense?

In order to decrease the number of false positives, I came up with a couple of possible solutions. Create two different types of Bloom filters; eg. filter1 using 3 different hash algorithms, filter2 ...
-1
votes
1answer
64 views

How implement a doubly linked list using single pointer inside? [closed]

struct{ int value; int *pointer; } I want to make doubly linked list using the above structure.
1
vote
3answers
234 views

Including extra headers that I do not really need

I always wondered what are the effects of including not needed headers to the final executable once compiled. In my code some times I may included many different headers that I do not need (or I used ...
2
votes
1answer
194 views

Quickest sorting algorithm for sorting a low number of integers

I am making a program on my spare time that I want to run as quickly as possible. The program is written in C. A large set of the procedures operate on pointers to 7 integers that are sorted by their ...
24
votes
7answers
2k views

Is it good practice to rely on headers being included transitively?

I'm cleaning up the includes in a C++ project I'm working on, and I keep wondering whether or not I should explicitly include all headers used directly in a particular file, or whether I should only ...
1
vote
1answer
73 views

Holding of files being edited in a text editor

I'm writing an implementation of Ex (hopefully Vi eventually) as a personal project. I need to somehow store an identifier for the file associated with each buffer. In terms of security/race ...
0
votes
0answers
83 views

In-place merging of sorted intervals in an array?

So I have code producing k sorted intervals in an n-sized array. What I'm brainstorming is the possibility of in-place merge of these intervals into a single sorted interval/array. The problem is ...
4
votes
2answers
164 views

When should a trig function, with a degree argument, return -0.0?

In creating trig functions my_sind(d), my_cosd(d), my_tand(d), that used a degree argument rather than a radian one and provided exact answers at multiples of 90, I noticed that the result was ...
0
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3answers
123 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 ...
6
votes
1answer
208 views

Do any notable C extensions include integer types that are independent of machine word size

An interesting characteristic of C compared with some other languages is that many of its data types are based upon the word size of the target architecture, rather than being specified in absolute ...
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vote
2answers
364 views

Generics in low level languages

I'm developing a language like Vala and OOC that compiles back to C. This means that, eventually, every feature needs to be adoptable to C code in some way or another. Generics is one of the features ...
7
votes
2answers
205 views

Autoreleasing objects in Reference Counting Systems

I'm experimenting a bit in C and I'm trying to implement my own Reference Counting System. I've mainly worked with Objective-C in the past but AFAIK autoreleasing objects is something that is unique ...
1
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0answers
65 views

Is conversion from C/C++ to Verilog/VHDL for FPGA a derivative work? [duplicate]

Say I have a C/C++ software licensed under GPL that gets converted into hardware design. By this conversion I mean that the exact functionality of the original software is being programmed into an ...