Implementing simple menus with select

With the Bash shell, it is possible to create simple menus with the help of the built-in select command.

The syntax of select is as follows:

            PS3=prompting-text 
            select VARIABLE in item1 item2 item3 
            do 
              commands 
            done

The advantage of a menu with select is that we can have an endless loop with it. We can have a condition in which we exit the loop.

In the following script, select_01.sh, we show the menu with five options including a, bc, def, ghi, and jkl. The script will execute the command inside do and done:

#!/bin/bash 
select var1 in a  bc   def    ghi   jkl 
do 
echo "Present value of var1 is $var1 
done

Let's test the program:

$ chmod +x select_01.sh$ ./select_01.sh

The following will be the output after executing the preceding commands:

1) a2) bc3) def4) ghi5) jkl#? 2"Present value of var1 is bc#? 4"Present value of var1 is ghi#? 5"Present value of var1 is jkl#?Press     ^C    to quit

We can...