linux

Please explain the purpose of the exec function and what happens when it is called? 2.\#1/bin/bash echo "*cmd menu* 1-date 2-Is 3-who 4-pwd 0-exit " while: do HCapture the user's typed value read - p "please input number :" n n1= 'echo $nseds/[09]//g ' if [z"$n1]#(1) then continue fi if [n$n1]#(2) then exit 0 fi break done case $n1 in 1) date+\%Y\%m\%d;; 2) Is | WC +: (1) 3) who i (2) 4) pwd ;i (3) 0) break;; (4) \# prompts for entering numbers other than 1-4 ) echo "please input number is [14] esac What is the exit status when the test conditional test expression holds? Explain the result of the execution of step (1)(2)(3)(4)