custom_kernel/prep.sh

#!/bin/bash

function ubuntu_ {
echo -e ""
sudo apt-get update
sudo apt-get upgrade -y
sudo apt-get install wget build-essential bison flex libncurses-dev libssl-dev libelf-dev dwarves ubuntu-dev-tools lzop zstd -y
sudo apt-get install debhelper -y
exit
}

function redhat_ {
echo -e ""
sudo dnf -y groupinstall 'Development Tools'
sudo dnf -y install ncurses-devel openssl-devel elfutils-libelf-devel python3 dwarves
exit
}

clear
PS3="Select item please: "
items=("$(tput setaf 11)Ubuntu$(tput sgr0)" "$(tput setaf 9)Redhat$(tput sgr0)")
echo "$(tput sgr0)Make your choice:$(tput sgr0)"
select item in "${items[@]}" Quit
do
    case $REPLY in
        1) ubuntu_ ;;
        2) redhat_ ;;
        $((${#items[@]}+1))) echo "We're done!"; break;;
        *) echo "Ooops - unknown choice $REPLY";;
    esac
done