Write a shell script to display the numbers of rows, columns and OS Type using system variables. Write a Shell Script that adds five numbers if provided as the command Line Argument and if the five numbers are not entered it outputs an Error Message. Write a for loop to be executed in sh which goes through your directory "/usr/XYZ/letters" (you are XYZ) and for each file in the directory, find the number of lines and display it with the name of the file. Write a shell script to pass the name of a file as a command line argument and check if it exist, then rename it as filename.new.hct, if not exist then display the message not exist. Define different types of users: how you can add a new user explain with the help of examples