Скачать или смотреть frank 0102 5 of 20 write a public domain GPS interface to chrony March 3, 2026

This is my 102st video and my 5th GPS NMEA to chrony video.

Write a simple, public domain, interface between a GPS receiver outputting NMEA sentences and chrony. Unlike ntp and ntpsec, chrony does not include any GPS drivers. It is not hard, but it is not obvious how to write the interface.

I read several C guidelines on the interweb at colleges and universities. I was disappointed. The ones I read were not, in my opinion, very good.

google for "c source code guidelines site:.edu"


I want a C guideline that addresses the Top 25 Common Weakness Enumeration (CWE). In my opinion, most of the C style guides just tell me how to space the source code. I came up with my own C guidelines that try to take on the issues that appear in the Top 25 year after year after year.

I copied the ctags source code from NetBSD and compiled it
on a Linux machine using a make file with the Airbus flags.
I also ran scan-build on ctags and the static analyzer on
the Linux machine. It showed using garbage data from an
variable.

This is 2026. Has no one at NetBSD run the NetBSD source code
through a static analyzer? ctags was originally written in the
1970's for 2BSD.

I put all of my code on my Google Drive:

https://drive.google.com/drive/folders/1OK...



1. Frank C guideline: == number one rule. Do not read, do homework.

Write a small C and make program for each example in the Top 25, Cusp,
and Stubborn CWE. It took 6-8 weeks for me. I worked 1-2 hours everyday.

I did not just come up with the rest of the rules on my list.

I wrote an example C program and modified my make file to observe which
compiler flag or sanitizer or linter or static analyzer or dynamic analyzer
exposed the CWE.


2. Frank C guideline:

Use the JPL and Airbus GCC and clang flags.

use -fsanitize=address,leak,undefined


3. Frank C guideline:

use Valgrind and a static analyzer and a linter.


4. Frank C guideline:

Check buffer size == number 1 defect in C programs. HIGH PRIORITY


5. Frank C guideline:

No banned.h functions.

Show banned.h === this


6. Frank C guideline:

Set pointers to NULL immediately after free( ) (CERT RULE)

7. Frank C guideline:

This is the only C source code formatting and spacing I would recommend:

No implied blocks. Put { } around everything.

Safety people at nuclear power plant, MISRA, AUTOSAR, etc. recommend this.


8. Frank C guideline:

Validate parameters. Many C guidelines recommend this.


9. No function-like Macros.

Side effects.
No type safety.
Debugging issues.
Undefined behavior.

10. Separate assignment statements from evaluation/condition statements