1. Run the “top” command and explain the output. Which process is using the most CPU and memory?¶
By running the top commands on my machine I got the following results:
The processes that are using most memory are kernel_task and WindowServer and both of them are related to the operating system.
The first one is the kernel process and the second one is the file system and folders view program (Finder and desktop GUI).
2. How would you kill a process in a Linux terminal?¶
To kill a process, you must uniquely identify the one process that you want to kill and pass that identifier as an argument to the kill executable.
A good identifier would be the process id (PID) which can be supplied to the -9 option.
Some options may include using ports (kill any processes running on port X) or piping the grep function to search for processes that match a specific name.
Below, I will kill the top process that we started in the previous question with its PID:
we can see from the previous image that the PID for the top function is 47688
We will use the command: kill -9 47688 in a new tab while the old tab is still open.
The command itself has nothing to report, but the terminal where I was running the top reported that the process is killed and updating the numbers has stopped.
3. Run the following commands and explain the output and describe the differences - ps - pstree¶
Both of these commands prints the running process; but while ps print them as a list, pstree prints them as a nested list that help identify the parent/child relationships between processes.
