Author here. Happy to answer questions about the methodology or the c-from-scratch project.

I liked the overview and examples. But your program has no output?

Good observation! The shift is intentional - safety-critical code typically doesn't "output" in the printf sense. Instead it returns status codes and modifies state that the caller inspects.

The pulse monitor example returns PULSE_OK/PULSE_ERR_* codes, and the caller queries state via pulse_status(). In a real system, that status feeds into a larger state machine or triggers hardware responses - not console output.

That said, the c-from-scratch repo (https://github.com/SpeyTech/c-from-scratch) does include demo programs with actual output for learning purposes.

The article focuses on the methodology shift rather than a complete runnable example.

Fair point though - I could add a note about where to find working demos.

I like the shift in emphasis to testing over just looking for output, but part of the point of a "hello world" program is to make sure the output is working. If it helps, you could frame it as debug output instead of a result. "Sending pulse...", "Received pulse!".

Creator here. Thanks to whoever submitted this!

C-Sentinel came from 30 years of UNIX systems work and one frustration: monitoring tools tell you what happened, not why it matters.

The idea is simple: capture a system "fingerprint" (processes, configs, network, audit events), let an LLM reason about the combination of signals, and surface non-obvious risks.

Some design choices that might interest HN:

Pure C99, 99KB binary - no runtime dependencies, runs anywhere Privacy-first - usernames hashed, no PII in output Auditd integration - who accessed /etc/shadow and why "Why this score?" - explainable risk factors, not black box

Built as a wee project, launched on LinkedIn, somehow hit 23K impressions. Now here. Wild.

Happy to answer questions about the architecture, the C choices, or why I didn't use Rust (short answer: portability and simplicity).

Repo: github.com/williamofai/c-sentinel Live demo: sentinel.speytech.com