Use the history function to retrieve the command line you used in exercise 19. use the edit function to remove the word "clear" and replace it with "date." next, go to the beginning of "cal" and delete the text on the line from "cal" to the end. now, change the -h to -u. finally, add "; date -u" so that your final command-line entry is: who -u ; date -u. execute the command-line entries.