Run cat /var/log/auth.log | grep denied | wc -l.
cat /var/log/auth.log | grep denied | wc -l
Mission 49
Pipeline counts
Filter logs through safe text pipelines.
Text and logscatgrepwcjournalctl
Lesson 49 of 360
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Text and logs · 8 minutes
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learner@clairos:/home/learner $
Unix ops lab: type a command, press Enter
Instructions
8 minutes
Click any instruction for the command details, the why, and the common mistake to avoid.
Run journalctl -u ssh | grep denied.
journalctl -u ssh | grep denied
Run cat /home/learner/data/ports.txt | sort | uniq.
cat /home/learner/data/ports.txt | sort | uniq
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Lesson support
What to notice while you play.
Count filtered lines without leaving the simulator.
Pipe auth.log into grep denied, then wc -l.
Pipelines are a daily Unix skill for triage and reporting.
- Piping unsupported commands.
- Forgetting the filter before the count.
Reference
Commands in this lesson.
cat <file>
Print text file contents.
grep [-i] <text> <file>
Find literal text inside a file.
wc [-l] <file>
Count lines, words, and characters.
journalctl -u <service>
Read simulated service journal entries.