(16%) Assume you are running the following commands on the mypasswd file which has any number of lines (at least 50) of the following format: u1192345:x:520:66:Muhammd_Subhi:/home/comp311/u1192345:/bin/bash Write a single command to do each of the following: 1- display the last names of all users whose default shell is ksh and whose first name is Samer (all cases) 2- display the first and last names of all comp231 users after changing last names that are "hamdi"(all cases) to "newname" 3- display the user id numbers of all users whose last name is hamdan (all cases) 4- display the last names of all the users whose first names starts with the letter 'd' or 'D'.