Red Hat Linux 8 Bible — learning notebook
Article: https://yenra.com/red-hat-linux-8-bible/
Prepared: September 15, 2026
Book identity: Chris Negus, Wiley, 2002; ISBN 9780764549687.
This is distinct from Linux Bible, 8th Edition and from RHEL 8.

Repeat the following record for each lesson.

BOOK AND QUESTION
Your copy's title / edition / page:
Task being taught:
Concept in your own words:
Historical assumptions (paths, packages, privileges, service manager):

CURRENT ENVIRONMENT
Distribution and release:
Shell / tool / application versions:
Current official documentation URL and date checked:
Changes needed for this environment:
Potential effects and recovery route:

BOUNDED EXERCISE
Invented input or practice files:
Predicted result:
Command or procedure:
Observed output:
What passed / what remains uncertain:
Next exercise or explanation:

KNOWN-ANSWER SHELL EXERCISE
printf '%s\n' 'pear' 'apple' 'pear' | LC_ALL=C sort | uniq -c

Expected records: 1 apple; 2 pear (leading spacing may vary).
The command uses supplied text and does not modify files.
The sort makes duplicates adjacent; uniq -c counts adjacent duplicates.

References:
https://books.google.com/books/about/Red_Hat_Linux_8_Bible.html?id=y39GAAAAYAAJ
https://manpages.debian.org/trixie/bash/bash.1.en.html
https://manpages.debian.org/trixie/coreutils/uniq.1.en.html
https://manpages.debian.org/trixie/systemd/systemctl.1.en.html