Write a small shell script which does the following using shell functions:

1. Goes into a loop and prints out a menu with three options

1. Query the user for a month and year, then show the month using the cal command

2. Show who is logged on, then let the user send a message to another logged on user

3. Queries for a filename, then prints out the file type (file command), the owner, and the

file permissions

2. Reads the users selection and performs the selected function

3. Allows the user to exit the program with a return code of 0