FPSC- Programmer (BS-17) - PMD High Yield - 2026 — Test 9

Correct Answer: D. It takes effect immediately but is lost after a reload or reboot
Explanation: Use --permanent and then firewall-cmd --reload to keep the rule. ALSO KNOW (related points): • Which file on RHEL shows the exact release version? → /etc/redhat-release

Correct Answer: B. It switches SELinux to permissive mode, logging violations but not enforcing them, until the next reboot
Explanation: Permanently disabling SELinux requires editing /etc/selinux/config and rebooting. ALSO KNOW (related points): • Which command shows the current SELinux mode? → getenforce

Correct Answer: C. SIGTERM (15), which asks the process to terminate gracefully
Explanation: SIGKILL (kill -9) cannot be caught or ignored, so the process gets no chance to clean up. ALSO KNOW (related points): • Which signal can a process NOT catch, block, or ignore? → SIGKILL • Why is nohup used, as in nohup ./longjob.sh &? → So the process keeps running after the user logs out (it ignores SIGHUP) • Which command shows memory usage, including swap, in human-readable units? → free -h

Correct Answer: B. -20 to 19; -20 is the highest priority
Explanation: Only root can lower a nice value (raise priority). Regular users can only increase it. ALSO KNOW (related points): • What does appending & to a command (for example, ./backup.sh &) do? → It runs the command in the background of the current shell • Which key sequence suspends (stops) the current foreground job? → Ctrl+Z • Which column in ps aux output shows a process's state, where 'R' means running and 'S' means sleeping? → STAT

Correct Answer: B. A process that has finished but whose exit status has not yet been collected (reaped) by its parent
Explanation: It appears with state 'Z' in ps output. Killing it has no effect; the parent must reap it. ALSO KNOW (related points): • What happens to an orphan process whose parent exits? → It is adopted by PID 1 (systemd), which later reaps it • Which command gives a live, continuously updating view of processes and resource usage? → top • Which command lists the open files of a process, or shows which process is holding a file open? → lsof

Correct Answer: B. The first sends both stdout and stderr to the file; the second sends stderr to the terminal and only stdout to the file
Explanation: Redirections are processed left to right. 2>&1 copies wherever stdout points at that moment. ALSO KNOW (related points): • What is the difference between > and >>? → > truncates (overwrites) the file; >> appends to it • In which section of the man pages are system administration commands (such as useradd) documented? → Section 8 • What does touch newfile.txt do if newfile.txt already exists? → It updates the file's timestamps without changing its contents • What does mv old.txt new.txt do when both are in the same directory? → It renames the file

Correct Answer: D. uniq removes only adjacent duplicate lines, so the input must be sorted first
Explanation: sort -u combines the two steps. ALSO KNOW (related points): • What is the file descriptor number of standard error? → 2 • What does grep -v error log.txt print? → The lines that do NOT contain 'error' • What does wc -l file.txt report? → The number of lines (strictly, the number of newline characters)

Correct Answer: C. It replaces only the first occurrence of 'old' on each line
Explanation: Add the g flag (s/old/new/g) to replace every occurrence on a line. Use -i to edit the file in place. ALSO KNOW (related points): • What does tail -f /var/log/messages do? → It shows the last lines and keeps printing new lines as they are written • What does awk '{print $2}' file print? → The second whitespace-separated field of each line • What does ls -l | grep '^d' list? → Only the directories in the current listing

Correct Answer: D. cut -d: -f1,3 /etc/passwd
Explanation: Without -d, cut splits fields on tabs. -c selects characters. ALSO KNOW (related points): • What does command | tee output.txt do? → It writes the output to output.txt and also shows it on the screen • Which command shows the full path of the executable that runs when you type a command name? → which • What happens when you run rm -rf / as root on a modern system without any extra options? → GNU rm refuses, because --preserve-root is on by default

Correct Answer: B. find /home -mtime -7
Explanation: -7 means less than 7 days ago. +7 means more than 7 days ago. ALSO KNOW (related points): • Which files are hidden by default in ls output? → Files whose names begin with a dot (.) • Is the Linux filesystem case-sensitive? → Yes; Report.txt and report.txt are different files • What does the command chmod -R 755 /var/www do? → It applies 755 recursively to /var/www and everything inside it, including files, which then become executable