How to generate dynamic menu and make it usable?

Question

I'm trying to create script that will generate menu with filenames stored in specific folder and then allow me to print that file content with cat after entering number assigned to that file. The loop I have made works perfectly in terms of menu generation, but I don't know how to automaticly set variables and use them in order to print that files content or generate case structure (not sure which approach is better in this situation). My loop looks like this:

number=1
for file in ./menus/*; do
  echo "$number)" `basename -s .sh "$file"`
  let "number += 1"
done

Answer 1

Instead of complicated case / if statements, you can make a trick and use an array to store filenames inside, and then just call the file you need using it's array index:

number=1
for file in ./menus/*; do
fnames+=($(basename -s .sh $file))
#OR just fnames+=( $file )
echo "$number)" `basename -s .sh "$file"`
let "number += 1"
done
read -p "select a file id" fid
fid=$(($fid-1)) # reduce user input by 1 since array starts counting from zero
cat "${fnames[$fid]}.sh" # or just cat "${fnames[$fid]}" 

You can also make your jobe with a nice GUI using Yad (an advanced fork of Zenity) like bellow.
In this case you don't need numbering - you just select the file from a GUI list, and by pressing enter or click at ok you cat the selected file and you can see it's content on a new yad window.

As a single line command in bash (for testing):

fc=$(basename -s .sh $(find . -name "*.sh") |yad --list --width=500 --height=500 --center --column="File" --separator="") && cat $fc.sh |yad --text-info --width=800 --height=300

As a script:

yadb=0
while [ $yadb -eq "0" ];do 
    fc=$(basename -s .sh $(find . -name "*.sh") |yad --list --width=500 --height=500 --center --column="File" --separator="")
    yadb=$?
    if [ $yadb -eq "0" ]; then 
       cat $fc.sh |yad --text-info --width=800 --height=300
    fi
    # If you press cancel on yad window , then yadb will become 1 , file will not be displayed and while loop will be ended.
done

Answer 2

Use dialog for that...

apt-get install dialog

Example:

#!/bin/bash

HEIGHT=15
WIDTH=40
CHOICE_HEIGHT=4
BACKTITLE="Backtitle here"
TITLE="Title here"
MENU="Choose one of the following options:"

OPTIONS=(1 "Option 1"
         2 "Option 2"
         3 "Option 3")

CHOICE=$(dialog --clear \
                --backtitle "$BACKTITLE" \
                --title "$TITLE" \
                --menu "$MENU" \
                $HEIGHT $WIDTH $CHOICE_HEIGHT \
                "${OPTIONS[@]}" \
                2>&1 >/dev/tty)

clear
case $CHOICE in
        1)
            echo "You chose Option 1"
            ;;
        2)
            echo "You chose Option 2"
            ;;
        3)
            echo "You chose Option 3"
            ;;
esac