Linux basics check

Ten questions across the filesystem, pipelines, permissions, services and networking.

Pass mark: 70% · 10 questions

1. 1. During an incident, logs live under…

   /etc/var/log/usr/bin

2. 2. What does the pipe | do in `cat log | grep 403`?

   Runs both commands in parallelFeeds cat's output into grep's inputWrites to a file called grep

3. 3. chmod 600 secret.key results in…

   rw- --- --- — owner read/write onlyrwx rwx rwxr-- r-- r--

4. 4. 'Permission denied' when running ./deploy.sh usually means…

   The file is missingThe execute bit is not set — chmod +x deploy.shYou must reboot

5. 5. systemctl enable nginx does what start does not:

   Starts it right nowMakes it start automatically at bootInstalls nginx

6. 6. A service listening on 127.0.0.1:5000 is…

   Reachable from the whole networkReachable only from this machine (loopback)Blocked by the kernel

7. 7. Which prints only usernames from /etc/passwd?

   cut -d : -f 1 /etc/passwdgrep users /etc/passwdwc -l /etc/passwd

8. 8. kill 1234 vs kill -9 1234?

   Identicalkill sends SIGTERM (graceful); -9 SIGKILL (force, no cleanup)-9 is politer

9. 9. Select ALL correct pairings:

   dig — DNS resolutionss -tlnp — who is listening on which portchmod — change file owner

10. 10. First command in the 60-second service triage?

    rebootsystemctl status <service>rm -rf /tmp