This is a 25 year old book about Linux programming.

Much of the contents is still true, but parts are outdated.

The value of shipping such generic documentation in Debian
has also decreased with everyone having an internet connection
and far more online resources available today.

This book is still sold at almost 19,00 euros in paper and kindle formats.
Today it is probably Non-Advanced, but most of the stuff is still valid. Even the
'The Linux Programming Interface: A Linux and UNIX System Programming Handbook'
is a 16 years old books about the topic, still sold at more than 90
euros. It would be nice if both them would see an update for sure, but

I honestly think that a structured book is still better of any (what?)
internet resource. If one thinks to the amount of net resources
available and the role of AIs, I think nobody would write a technical book on any
topic, nowadays.

The day it will happen, also the AI will stop to advance and the
internet information will be simply permanently obsolete.

Let me disagree about such an idea, honestly.