Hello I am just trying to understand what a couple of these linux commands are doing in this piece of code fragment in C. I do not understand what "grep -w Z" and "cut -d ' ' -f 5" are doing. I thought grep -w just gets the line that matches the word, but what does the Z part do? Also I do not understand what cut -d ' ' -f 5 is doing. Can someone please explain clearly and concisely.

Code fragment:

system("kill -9 $(ps -1|grep -w Z|tr -s ' '|cut -d ' ' -f 5)");