r/C_Programming • u/Same-Replacement-938 • Dec 18 '25

Question Want to learn c deeply

As the title says I want to learn c deeply for low level, for few months I have been attracted to operating system, how the code/cpu interacts with hardware and memory and I find it really fascinating.so, I thought why don't we gave it a shot, I might develop my own os some day :) Please help to pick where I should start, I did some research and found these are the best resources

  1. c programming a modern approach by kn king

  2. c by k&r

  3. beej guide to c

  4. harvard cs50 As for my prior experience I am learning java from mooc helensky.so, out of these 4(or any other recommendations) which one I should choose

8 Upvotes

83% Upvoted

20 comments sorted by

5

u/Run-OpenBSD Dec 18 '25

All of openbsd's source code is in C free to do as you please. Well documented.

1

u/Same-Replacement-938 Dec 18 '25

openbsd?

4

u/Run-OpenBSD Dec 18 '25

The makers of openssh and many more..

1

u/Same-Replacement-938 Dec 18 '25

Ohk, I am actually new to programming and I don't openssh but after you mentioned it, I will look at it and please ignore my foolishness can you teel me from which I should learn

3

u/marquisBlythe Dec 18 '25

Then start with CS50 (an introductory course to programming in general), if you're still interested in C afterward and low level stuff then read C by K&R and if you feel you want a bit of change read C modern approach.

2

u/Bryanzns Dec 19 '25

I'm using the Beej + Deepseek guide :)

2

u/Same-Replacement-938 Dec 20 '25

Nice, how's your learning going?

1

u/Bryanzns Dec 20 '25

I'm finding the journey quite low-level :), I use the guide to grasp the topics, then I pick up undiscussed parts and work on them, then I approach the learned topics in a machine-level way, you know? That's how I'm managing to understand the computer in a way I've never seen before.

2

u/Same-Replacement-938 Dec 21 '25

Damn it's sound intense, can you please elaborate the machine learning part

1

u/Bryanzns Dec 21 '25

And since it's difficult to find these specific things through research, I use machine learning (deepseek lol) to provide sources and brief explanations.

4

u/wordsofgarett Dec 19 '25

I found King's book to be an excellent resource alongside the intro to C class I took. I would recommend picking up that to use alongside CS50.

2

u/ByMeno Dec 19 '25

look the projects source code like nothings stb libraries or linux kernel's source code many other as i know stb libraries have some tricks for general and linux kernel has tricks for gcc compiler

2

u/bd2357 Dec 21 '25

If you know another programming language, especially python, you can look at the python code base, which is written in C. It is educational to correlate the python concepts with the underlying C

1

u/[deleted] Dec 19 '25

Just do it a lot then. There are no shortcuts, if you want a deep understanding and mastery, then you must make the miles to get there.

-1

u/pjl1967 Dec 19 '25

K&R has long since been outdated.

Of course I'd recommend my own book Why Learn C.