Wiki/grub.md

Grub

• Get Menu number:

#!/bin/bash

# NAME: grub-display-lite.sh
# PATH: $HOME/bin
# DESC: Written for AU Q&A: https://askubuntu.com/q/1019213/307523
# DATE: Mar 26, 2018.
# NOTE: "lite" version written for Ubuntu Server and Lubuntu which do
#       not have `dialog` installed by default. `whiptail` is used
#       instead. Nice consequences are better resolution, mouse scroll
#       wheel and copy to clipboard support.

# $TERM variable may be missing when called via desktop shortcut
CurrentTERM=$(env | grep TERM)
if [[ $CurrentTERM == "" ]] ; then
    notify-send --urgency=critical "$0 cannot be run from GUI without TERM environment variable."
    exit 1
fi

# Version without upstart and recovery options displayed
awk -F\' '/menuentry / { print i++, $2}' /boot/grub/grub.cfg \
        | grep -v upstart | grep -v recovery > ~/.grub-display-menu

# Version with upstart and recovery options displayed
#awk -F\' '/menuentry / { print i++, $2}' /boot/grub/grub.cfg \
#        > ~/.grub-display-menu

MenuArr=()

while read -r line; do 
    MenuNmbr=${line%% *}
    MenuName=${line#* }
    MenuArr+=($MenuNmbr "$MenuName")
done < ~/.grub-display-menu
rm ~/.grub-display-menu

LongVersion=$(grub-install --version)
ShortVersion=$(echo "${LongVersion:20}")
DefaultItem=0

while true ; do

    Choice=$(whiptail \
        --title "Use arrow, page, home & end keys. Tab toggle option" \
        --backtitle "Grub Version: $ShortVersion" \
        --ok-button "Display Grub Boot" \
        --cancel-button "Exit" \
        --default-item "$DefaultItem" \
        --menu "Menu Number       ----------- Menu Name ----------" 24 76 16 \
        "${MenuArr[@]}" \
       >/dev/tty)

    clear
    if [[ $Choice == "" ]]; then break ; fi
    DefaultItem=$Choice

    for (( i=0; i < ${#MenuArr[@]}; i=i+2 )) ; do
        if [[ "${MenuArr[i]}" == $Choice ]] ; then
            i=$i+1
            MenuEntry="menuentry '"${MenuArr[i]}"'"
            break
        fi
    done

    TheGameIsAfoot=false
    while read -r line ; do
        if [[ $line = *"$MenuEntry"* ]]; then TheGameIsAfoot=true ; fi
        if [[ $TheGameIsAfoot == true ]]; then
            echo $line
            if [[ $line = *"}"* ]]; then break ; fi
        fi
    done < /boot/grub/grub.cfg

    read -p "Press <Enter> to continue"

done

exit 0