C tutorials geared towards maintaining existing code

[David Delony]

I'm interested in contributing to open source projects, most of which
are written in C. All of the tutorials I've found emphasize writing
programs from scratch. I'm interested in both on-and-offline
newbie-friendly tutorials that show how to maintain existing code.

 

[Roland Pibinger]

I'm interested in contributing to open source projects, most of which
are written in C. All of the tutorials I've found emphasize writing
programs from scratch. I'm interested in both on-and-offline
newbie-friendly tutorials that show how to maintain existing code.

(it depends on what you mean by 'newbie-friendly')

Diomidis Spinellis: "Code Reading: The Open Source Perspective"
http://www.spinellis.gr/codereading/

Examples are predominantly in C (some in Java, C++, ...)