Select and Case statements using BASH - bash

Question

The idea behind this code is to print options to the user and allow them to execute commands. The file name is example.sh. I simply run it by ./example.sh and it gives 3 options: author, type, exit.
NAME="Mark Zuck"
PS3="enter command: "
select var in author type exit
do
case $var in
author)
echo $NAME
;;
type)
cat $2
;;
exit)
exit
;;
esac
done
Whenever I type author, the output is Mark Zuck, but I am trying to execute the command "type".
After putting 2 <"file name">, it should give me the contents of the file.
cat $2 doesn't work. I don't know how to solve this issue.
1) author
2) type
3) exit
enter command: 2 file1
enter command:
The output is above.
It should give me the content of the "file1" (file1 does exist)

Answer 1

select returns two values:
The first is in your custom var and contains the token associated to the number in select list
The second is in REPLY (like built-in read command) and contains the number
Ok? it's the standard test case.
If you type another response on select prompt, var is nul (empty) and REPLY contains the response!
So, I think, this script is for you.
Of course, the coma (,) is not adapted for you, it's just an example. Use what you want.
#! /usr/bin/env bash
NAME="Mark Zuck"
PS3="enter command: "
select var in author type exit
do
case "$var,$REPLY" in
"author,1")
echo "$NAME"
;;
",2 "*)
filename="${REPLY#2 }"
echo "filename=<$filename>"
cat "${filename}"
;;
"exit,3")
exit
;;
esac
done
Test:
> bash --version
GNU bash, version 5.2.9(1)-release (x86_64-redhat-linux-gnu)
> ./test_select.sh
1) author
2) type
3) exit
enter command: 1
Mark Zuck
enter command: 2 test_select.sh
filename=<test_select.sh>
#! /usr/bin/env bash
NAME="Mark Zuck"
PS3="enter command: "
select var in author type exit
do
case "$var,$REPLY" in
"author,1")
echo "$NAME"
;;
",2 "*)
filename="${REPLY#2 }"
echo "filename=<$filename>"
cat "${filename}"
;;
"exit,3")
exit
;;
esac
done
enter command: 3
>