Processes

Question 1

What is systemd (formerly init)?

Answer 1

systemd is the first process that is started by the kernal at boot, it also reparents processes that have lost their partent

Question 2

What is the command to send a process a signal?

Answer 2

kill

pkill

Question 3

What us the default signal sent by kill?

Answer 3

15

SIGTERM - tells process to stop

Question 4

What is the command to kill a process abruptly if it is not responding?

Answer 4

kill -9

SIGKILL - instructs kernel to kill a process

Question 5

What is the command to get a list of process signals (syntax)?

Answer 5

kill -l

Question 6

How can you search for a process?

Answer 6

pgrep

ps -aux | grep

Question 7

When searching for a process what will be returned?

Answer 7

The process searched if it exists and the grep process searching for it

Question 8

What kill signals cannot be caught, blocked or ignored?

Answer 8

SIGKILL

SIGSTOP

Question 9

How do you run a process with a specified priority?

Answer 9

nice -n 4 firefox

*n value between -20,19

Question 10

What are the 4 states a process can be in?

Answer 10

running - eligible to be scheduled for CPU time, will be run
sleeping - waiting for something
zombie - finished computing, waiting to return information/terminate
stopped - stopped waiting for SIGCONT to resume

Question 11

What is a reason that a process could be in a zombie state?

Answer 11

Waiting to return information or waiting on parent process to complete

Question 12

What is the command to change the priority of a process?

Answer 12

renice -n -14

*n value between -20,19

Question 13

What is the location of process information in the file system?

Answer 13

/proc