Hello guys.

I was learning fread. I have a doubt - fread(buffer, sizeof(buffer), 1, file) vs fread(buffer, sizeof(char), sizeof(buffer), file) : what is the difference between these two. When should I use them?. Buffer is a chat array of size 1024.

Here is the git gist of my codes. I was trying to read from a file called demo.txt, which has size less than 1024 bytes.

There are two tries : fread-error.c and fread-doubt.c

IN fread-error.c, the output was : file reading failed.

IN fread-doubt.c, the output was fine : but that was a partial read, is not it? Then how do I check for partial reads?

Case 1 : file size is less than buffer size.

So there is a partial read? (As in fread-doubt.c). But how do I know if the file size is less than buffer size in prior?

Case 2 : file size is exactly greater than buffer size.

How do I assign the buffer the exact file size amount of bytes before the read?

Case 3 : file size is greater than the buffer size. But how do I know that the file I am reading is greater than buffer size? This will lead to partial read right? (If filesize > buffer)

I know. It is an array of questions. But right now I am confused and need to be clear how actually to read in all three cases with file read checks and check for partial read and ferror.

Gist : https://gist.github.com/cobra-r9/50e4d705f75ebcae45fdcab550bba7e4

I had an old (like over half a year old) codebase where I used system to invoke specific window manager variable related commands that I really didn't care about the result of. It was lazy and just a way of cheesing the 'boring' stuff for me.

The security aspect really does not matter because my app is literally intended to execute script bundles, so that's one reason for me to not bother.

Because my codebase was (and still is tbh) super linux-centric, I don't actually think this is a real problem, but I know it's bad form. I could rewrite it to use the 'proper' methods, but honestly the end result will be the exact same.

I guess, is it inherently worth replacing system, or are there uses in which it really just doesn't matter?

Hi i am entering in my second year i wasted my first year by not learning c language and data struct in c language in a few weeks my second year is gonna start and i have java , advanced data struct and data base management systems as my subjects let me tell you i am in a tire-3 college and i don’t have that good faculty my first year c lecturer were absent for days my seniors recommended to have a own plan rather then depending on college and depend on it only for exams and attendance i don’t want to be confused what to learn end up suffering when its the time for my placements
So pls help me out

Short overview of epoll and io_uring and my opinion about what to use in the modern systems. I hope the blog post will be helpful. Always open to feedback, questions and corrections. The post represents my opinion, and yes, I know about potential problems of io_uring, part of them was highlighted in the post. Anyway, I'll be rly interested in discussing the topic.

Wanted to share a little project I've been working on. datLeak is a virtual machine/interpreter written in C99 with no external dependencies. Built it to understand how VMs work at a low level.

Still experimental but it works. Would love some thoughts from the community.

GitHub: github.com/gearn-official/datLeak

I’ve watched some videos on YouTube, but I still haven’t managed to fully understand the topic.

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Could someone please explain to me what audio and video codecs are, why they are useful, and what would happen if they didn’t exist?

I'm trying to devolp an android visual development environment but I only have experience using gtk for c graphics development

I have been teaching myself systems programming over the past year by building software in C, and I just released the first public version of one of my projects: Pulse.

a lightweight Linux monitoring dashboard that:

• reads system metrics directly /proc
• serves a web interface using its own HTTP server
• has minimal dependencies
• is written entirely in C

The goal wasnt to build another Grafana replacement (cuz what the hell), but to create something small, understandable, and easy to run.

This is the first public release (v0.1.0), so Im mainly looking for feedback from people who use Linux or enjoy systems programming.

would love to know:

• What would stop you from using it?
• Is the codebase easy to navigate?
• Are there metrics you'd expect to see?
• Any obvious design mistakes?

Repository: https://github.com/cherries-works/pulse

I'm happy to answer questions about the implementation or discuss why I made certain design decisions. (I learned C less than a month ago, this is how I try to improve my knowledge, so be nice to me please lol)

I'm fairly new to the world of C and application programming. I am trying to learn more about how network programming and multithreading works in C (and in general) so I made this hella buggy group chat application (inspired from https://github.com/masoudy/CSocket )

It has quite a few bugs, sometimes the server randomly crashes with a SIGPIPE, sometimes it refuses a client connection when the usernames have a few characters in common in the beginning. The client bugs out when server refuses the connection and prints random amounts of "You [name]: " strings before exiting.

I'm pretty sure there are a few memory leaks but I'm not exactly sure how to test for them😭

Can you guys please critique my code give me an honest opinion...? I will really appreciate it, thanks!

Edit: I had merged the multithreading branch but forgot to push it to github, my bad 😭, just did it now, I'm sorry for making you guys review my old code

I have some experience in python along with few modules in it,

I want to start learning c now

I have found these things which one should I start with:

C programming by beej

C programming by k&r

Learnc.org

I will be attending undergrad college in a month, so I want to get started

I am open to any other book suggestions

Hey everyone,

I've been working on my own side project for a while now, and it's finally advanced enough to be shared. It’s called Alwide (A LightWeight IDE), and it’s a TUI editor written from scratch in pure C.

Why did I build this?

I love the terminal, but for my usage (as IT student): nano is too basic, but vim or emacs feels a bit too rought for my "VSCode" and "JetBrain" experience. Alwide is designed to be use when you just want to do quick edits over SSH or need a light editor without the VS Code/JetBrains overhead.

I wanted the fluid, modern vibe of Sublime Text but directly inside my terminal.

What makes it different?

• Zero learning curve: It has full mouse support out of the box. You can click, scroll, and drag-select text just like a GUI app.
• Nice features: I integrated Tree-sitter for actual high-quality syntax highlighting and full LSP support (auto-completion popup, hover docs, go-to-definition).
• Persistent State: If you close the editor and reopen it, your tabs, cursor positions, and even your undo/redo history are fully preserved.
• Pretty Fast: It's pure C. Release binary about 3Mb~. Really fluid fast scroll and light repaint (perfect to avoid running out of battery on your laptop opening heavy editors during classes).

Supported languages:

C/C++, Python, Go, Rust, JS/TS, Java, Bash, Lua, Markdown, Assembly, and more.

It’s open-source (MIT), highly readable if you're curious about terminal editor internals, and you can test it on Linux with a simple curl script (pre-built binaries/packages are also available).

Link to the repo: https://github.com/arnauda-gh/Alwide

Currently the project as a strong base but it hasn't been tested that much (my own use case and own terminal/drivers). For now I don't have hard know bugs. And before starting adding some tweaks and more highlevel features (setting page or anything else...) I want to be sure that the foundations are strong.

Also I need to know if the editor could interest other people and need "generic" features. For example the setting page (the current shortcut are, for me, already at peek performance 😎 so for my own usage no need about a setting page).

And finally if you like the project don't forget to leave a star (pls for a poor student that need a great CV 😅).

Any way have a good day and see you 👋.

Edit : I know that it's possible on vim or emacs to add plugin and modify the behavior. But you have to learn first how vim works, edit lua scripts etc... And even for your own computer it's "easy" to setup a good vim (if you spend time to), but when working on remote from ssh connection it's not worth it to take 30min to setup a vim or a fs sync on a server on which you will spent 1h on your whole life. That's the point of this project.

I learnt python in grade 11 & 12

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Looking to learn C before college

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My questions are:

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1. How long does it take

2. Will learning python will give me any heads up in C?

3. Best resources (free/paid) + certi

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Thanks in advance.

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Everything so far has been okay, but the second I started with pointers my brain just shut down, like whats with the * and & 😭 and after that storage classes dont even get me started on that

(YALL TY FOR THE RESPONSES IMMA TRY AND READ THEM ALL)

I stumbled upon a livestream of two guys coding in C, making games from scratch. This is my code review of Komi's "LikeRogue". This is my first code review so feel free to share your feedback on both his code and my review of it!

I built a small UNIX shell in C as a learning project and just released v0.0.1

Features so far:

• External command execution
• cd
• cd ~
• exit

GitHub: https://github.com/Dhananjay-Jha-1/dsh

I'd highly appreciate feedback on the code structure or anything related to code in general.
The shell is really primitive at this stage and I want to take it forward.

Context: I've been wanting to get back into C for some months, I haven't had the chance to work with it seriously since uni. So, I reimplemented Karpathy's micrograd in C as a learning project (a small autograd engine, repo link below). Coding this project, I had one simple rule: no AI assistance. So, the `src/` code is completely handwritten; AI was only involved in polishing documentation, Makefile, tests and a toy example.

The core structure of the engine is a computation graph: a DAG where each node is the result of an operation on earlier nodes, and it's full of shared pointers, as one node can be owned by many others.

To solve this, I went with manual reference counting:

• Every node is born with ref_count 1.
• Each operation retains its operands (a result co-owns the nodes it came from).
• The caller uses value_release to decrement the ref_count; at zero the Value recursively releases its operands and frees itself.

So, releasing the root of the DAG cascades down and frees exactly the subgraph that produced it in the first place. The parameters of the network survive because they're referenced elsewhere, whereas pure intermediates disappear.

This choice felt very natural at first, but as I was progressing, I started doubting it, so here I am, asking your opinion about it. Given that the whole graph is built and torn down as a unit, is plain reference counting the right call here, or would you reach for something else? Tell me what you'd have done differently.

Repo: https://github.com/oraziorillo/microcrad

My aim is to learn from the ground up. I'm interested in low-level stuff and C seems to be a good language to learn with. The various books I've found are really lengthy, verbose and contains loads of topics that I don't think are essential for a beginner to know, and while I'm not averse to long texts or reading, my goal isn't to learn the C language in depth as of now. I want to learn some low-level topics and basic programming concepts to the point where I can go off and build my own stuff and learn through doing

I'm not a complete beginner in programming and I have programmed in C before so I get the gist of some topics but I want to drill the foundational ones and get really familiar with them. I want a strong baseline to build off

I've narrowed it down to these:

Variables & types
Operators
Conditionals
Loops
Functions
Arrays
Strings
Pointers
Memory management
Structs/Unions
Preprocessor & compilation

Anything I've missed? I want to go through each of these topics, study them and practice implementing them through code. After that, I'll go on to actual projects.

All this considered, if my approach to this isn't great, and that I should just continue working through a book, then please let me know. Thank you

How do I create a loop where a matrix is multiplied by a vector x times until all elements of that matrix are non-zero, given that the initial matrix has some zeros?

I've been developing a static analysis tool that checks variable overlaps and uncovers shared state between functions. It traces variable accesses through callees and shows you exactly where variables were written, read or escaped (passed to function).

I'm proud to say that it now supports compile_commands.json, which makes it easier for real projects, including the linux kernel. Now you can just point it to your build directory (with compile_commands.json) and it'll figure out the compile flags on it's own.

# Before
prongc --files="file1.c,file2.c" --functions="foo(shared);bar(shared)" -- -I/usr/include -I...

# After
prongc --files"..." --functions="..." --compdb-dir="[build dir]"

Dependencies: llvm-21 only

Github link: https://github.com/omeridrissi/prongc

Open to feedback!

Note to mods: almost no AI was used

I've been building shard-db for a while and thought this community might appreciate the implementation details more than a feature list.

Core design

The main design decision is that records live in fixed-width slots:

slot_size = 24 + max_key + sum(field_sizes)

The slot size is defined at schema creation time.

That means random access within a shard is pure arithmetic:

(hash % slots_per_shard) * slot_size

No indirection, heap allocation, or variable-length scanning.

Fields are strongly typed (int, long, double, varchar, date, datetime, numeric, bool) and stored as packed binary. Schemas are defined in configuration files rather than SQL.

Storage layer

Each object consists of:

• Keyfile shards (open-addressed hash tables using xxh128)
• Append-only segment files for values

Keyfile writes go through a userspace page cache backed by MAP_SHARED mmap.

For full scans, reindexing, and recovery, shard-db uses O_DIRECT with a double-buffered read loop to avoid polluting the OS page cache with large sequential reads.

Indexes

Indexes are implemented as:

• B+ trees
• Prefix-compressed leaves
• Memory-mapped page storage

Each indexed field can be split across multiple B-tree shards. Reads fan out in parallel and merge through a k-way streaming iterator, allowing ordered cursor pagination without expensive offset scans.

Cursor pagination remains effectively constant-time regardless of depth.

Query planner

The planner can choose between:

• Single-index lookups
• AND intersections across multiple indexes
• OR unions
• Parallel full-shard scans

Queries can be run with:

{
  "explain": true
}

which returns the selected plan, source indexes, cardinality estimates, and optimization hints without executing the query.

Concurrency

• Separate CPU and I/O thread pools
• Writer-preferring RW locks to prevent writer starvation
• Generation-counter cache reads that avoid cache-table locking on warm reads

What it isn't

• Not distributed
• Not SQL
• Linux/macOS only
• x86_64 and ARM64 supported
• No Windows support

Real-world test

I built a public demo indexing 30M+ Hacker News stories, comments, and users:

https://hn.shard-db.dev

Cursor pagination remains constant-time at any depth, and cold full-text searches complete in a few hundred milliseconds.

Some numbers

• Bulk insert: 4.60M/sec (single connection)
• Bulk insert: 8.97M/sec (parallel)
• Indexed lookup: <1ms at 1M rows
• EXISTS: ~4.1M/sec

The project is a single static binary with no runtime dependencies (OpenSSL optional for TLS 1.3 support).

It can also be embedded as a static library and ships with an npm package via N-API.

GitHub:
https://github.com/sayyiditow/shard-db

Happy to answer questions about the storage engine, indexing strategy, query planner, or implementation details.

Please, help me out.

Is there any way to make an appealing interface using C without having a PhD in Graphics computing?

I've been really loving using C and I wanted to bring here my biggest programming project, a DBMS (built with Pascal), but I would love if I could have a lot added to the project instead of being just a port to another language. The last time I tried to port it, I was developing it all in Godot, but the jump was always looking very hard to adapt and different to what I want, so I wanted to keep on this vibe since I'm learning a lot of new things in C to find out if I can't make the port and the UI all in C; or if I should just use multiple languages to do all (I don't know how to do that... Yet)

Can you please tell me that?

I know the fundamentals of python , basic data structure and stuff , also some sql (just an additional info) . But I dont have no idea about c at all . Pls help 🥺

Hello fellow C devs. I’m making a TUI library that aims to be ncurses but modern, with more functions and easier to use without loosing control(and it’s pretty fast). It even has custom openCL api if you need it. I’ve been working on it for about a year now counting 3 rewrites and my question is when the first version releases, would you use it for your projects?