CompTIA Linux+ Linux GNU and Unix Commands Flashcards

Which command sends a SIGKILL signal to a process with PID 1234?

Answer: kill -9 1234

Signal 9 (SIGKILL) forcefully terminates a process immediately without cleanup.

A script needs to run in the background and survive after logout. Which command achieves this?

Answer: nohup ./script.sh &

nohup prevents the process from receiving SIGHUP on logout; & puts it in the background.

What is the result of running 'mkdir -p /tmp/a/b/c'?

Answer: Creates /tmp/a, /tmp/a/b, and /tmp/a/b/c even if intermediate dirs don't exist

mkdir -p creates all intermediate directories in the path without error if they already exist.

Which command shows the full path of an executable named 'python3'?

Answer: which python3

which searches the PATH environment variable and returns the full path of the named executable.

A user types 'history | tail -5'. What is displayed?

Answer: The last 5 commands entered in the shell

history outputs all previous commands; piping through tail -5 shows only the last 5 entries.

What does the 'awk '{print $3}'' command extract from its input?

Answer: The third whitespace-delimited field from each line

In awk, $1, $2, $3 refer to fields split by whitespace; $3 prints the third field of each line.

Which command archives and compresses a directory 'project/' into 'project.tar.gz'?

Answer: tar -czf project.tar.gz project/

tar -czf creates (-c) an archive, compresses with gzip (-z), and writes to the named file (-f).