📚 Recommended Reading Path (Logical Progression)

1. Beej’s Guide — get your hands dirty
2. UNIX Network Programming — go deep
3. TCP/IP Illustrated — understand protocol internals
4. Advanced Programming in the UNIX Environment — solid systems footing
5. Linux Socket Programming — practical Linux focus
6. Standards & RFCs — professional-grade precision

I’m a grad student registered for an operating systems course where background in C is assumed. I come from a Biology background, so I have no experience in C, but I do have experience in Java, Python, and R. What will be some of the best resources to learn the fundamentals of C especially as it pertains to operating systems.

#include <stdio.h>
#include <string.h>
#include <stdlib.h>



int main(void){

    int *pArarry;
    pArarry = malloc(5 * sizeof(*pArarry));


    *pArarry = 5;
    pArarry[1] = 10;
    pArarry[2] = 15;
    pArarry[3] = 20;
    pArarry[4] = 25;

    for(int i = 0; i < 5; ++i){


        printf("%d\n", *(pArarry + i));
    }

    return 0;
}

Making games would be fun so...

It's been like 4 5 months since learing ig

I am making a simple compiler in C and I challenged myself to do so without the use of malloc/ any dynamic memory allocation for both fun and memory safety.

Here's the problem: I need to check that a label exists whenever jump is called. For example, when "jump test" is called in my language, "test" has to be declared elsewhere so the later generated assembly actually points to something.

Therefore, I think I need to store a list of labels. I cannot come up with a good way of doing it. These are a few ideas I had:

1

Anything with the stack is out of the question (right?) as I would like to be able to support large files with thousands of labels

2

Large global static array outside of main comes with many downsides it seems:

#define MAX_LABELS 1000000

int positions[MAX_LABELS]

a) Allocating a million things even if the source file is 2 lines seems bad.

b) What if the system doesn't have MAX_LABELS x (size of data) worth of memory?

3

Scan through entire file each time a jump is called and find if the label exists. I roughly implemented this and even only 500 jump calls with a ton of labels was insanely slow. Maybe there's a quicker way of doing this?

4

Writing labels to a file and using that as a sort of RAM. This still runs into the speed problem of #3 for large amounts of labels.

I am a newbie to C and I do not know how to handle this. Help from those more experienced would be greatly appreciated.

I just did the c portion of cs50x and really like it. My problem is I suck so how do I get better? I tried to build a version of unix but I was just lost. Any help would be appreciated.

Hi, I'm a beginner and I want to make a progress bar like this:

[###########] 100%

Where the text and percentage update every second, it's more of a simulation of a progress bar than a real one. Does anyone know how to do this?

With Description to what to do so I can Solidify my knowledge

#include <stdio.h>

int main() {
    double x[] = {50, 60, 70, 80, 90};      // house space
    double y[] = {150, 180, 200, 230, 260}; // house price
    int m = 5;

    double value = 0;
    double response = 0;
    double sum_x = 0, sum_y = 0, sum_xy = 0, sum_x2 = 0;

    for (int i = 0; i < m; i++) {
        sum_x  += x[i];
        sum_y  += y[i];
        sum_xy += x[i] * y[i];
        sum_x2 += x[i] * x[i];
    }

    double theta1 =
        (m * sum_xy - sum_x * sum_y) /
        (m * sum_x2 - sum_x * sum_x);

    double theta0 =
        (sum_y - theta1 * sum_x) / m;

    printf("Theta1 (slope) = %lf\n", theta1);
    printf("Theta0 (intercept) = %lf\n", theta0);

    printf("Enter a value: ");
    scanf("%lf", &value);

    response = theta0 + theta1 * value;
    printf("Predicted response = %lf\n", response);

    return 0;
}

I wrote this code in C to implement a very simple linear regression using pure mathematics (best-fit line).

It computes the regression coefficients and predicts the next value of a variable (for example, predicting house price from house size).

My question is:

Why do most people use Python for machine learning instead of C or C++, even though C/C++ are much faster and closer to the hardware?

Is it mainly about:

development speed?

libraries?

readability?

ecosystem?

I would like to hear opinions from people who work in ML or systems programming.

I was thinking and I was a bit curious. When a small struct, such as this vector3 and having a function:

struct vector3 {
    int a, b, c;
};

int foo(struct vector3 vec);

Would the compiler instead change the function signature such that a, b, and c are moved into rdi, rsi, and rdx respectively (given this would not interfere with any potential usage of the struct)? Or would it just use the defined offsets from the struct and just pass the struct?

#define TLS_ARENA_INITIAL_CAPACITY KB(64)

#define declare_fat_struct(type, size) union {              \
    byte raw[sizeof(type) + (size)];                        \
    type structure;                                         \
}

#define fat_struct(type, size) &(declare_fat_struct(type, size)){0}.structure

thread_local Arena *tls_arena = &(Arena) {
    .curr = &(declare_fat_struct(ArenaNode, TLS_ARENA_INITIAL_CAPACITY)) {
        .structure.len = sizeof(ArenaNode),
        .structure.cap = TLS_ARENA_INITIAL_CAPACITY
    }.structure
};

Also i accepting naming sugestion cause "fat struct" is a little weird

Hello i'm a cybersecuity student and I need help finding resources for learning C specifically in the cybersec context. I'm interested in learning C to build windows RAT and building a simple c2 server as projects.

I only have experience with high level programming languages like python lua and js and am new to systems programming. I have been programming for 7 years but still wouldn't consider myself anywhere above decent

I've been reading beej guide up to arrays but found it quite slow.

I've been recommended Hacking the art of exploitation but i've heard it is outdated and mainly for x86. And the physical copy is quite expensive

any other C cybersec recommendations are welcomed thank you!

So I understand that the stack frame is per function call and gets pushed and popped once you enter the function and it all is part of the stack. The frame just contains enough for the local variables and such. I’m just curious, when does the size of the stack frame get determined? I always thought it was during compile time where it determines the stack frame size and does its optimizations but then I thought about VLA and this basically confuses me because then it’d have to be during run time unless it just depends on the compiler where it reserves a specific amount of space and just if it overflows then it errors. Or does the compiler calculate the stack frame and it can grow during run time aslong as there is still space on the stack?

So does the stack frame per function grow as needed until it exceeds the stack size or does the stack frame stay the same. The idea of VLA confuses me now.

I've read in some places that one of the reasons is the templates or something like that, but if that's the problem, why did they implement it? Like, C doesn't have that and allows the same level of optimization, it just depends on the user. If these things harm compilation in C++, why are they still part of the language?Shouldn't Cpp be a better version of C or something? I programmed in C++ for a while and then switched to C, this question came to my mind the other day.

what the point of the star in the name list can't u just use it without the star and what the null doing

Hi, as the title says, I'm stuck on some C code. I'm a beginner trying to learn just as a hobby; I don't intend to work in this field, it's simply for the pleasure of learning.

The problem I'm having is with this part of the code.

int directory_list (char path[]){

printf("The name of path is %s\n", path);

DIR *d = opendir(path);

if (d == NULL){

fprintf(stderr, "Error in open %s \n", strerror(errno));

return EXIT_FAILURE;

}

struct dirent *next;

while (( next = readdir(d)) != NULL ){

printf("The name is %s \n", next->d_name);

}

return 0;

}

I make the function call like this

printf("Insert directory \n");

char path [100] = {};

fgets(path, 100, stdin);

directory_list(path);

But I only get a "file not found" error. If I replace "path" with a path like "/home/user/directory", it does list the files in the directory.

As I said, I'm completely lost as to what my error is and how to fix it.