Get first kernel version to be booted from Grub Config (menu.lst) - Ubuntu Kernels

grub_first_kernel_version.sh

#!/usr/bin/env bash

grub_config="/boot/grub/menu.lst"
if [ ! -f "${grub_config}" ]; then
	echo "Grub config ${grub_config} not found."
	exit 1
fi

boot_default=$(grep ^default "${grub_config}" | awk '{print $2}')
let boot_default_plus_1=$boot_default+1

version=$(grep ^kernel "${grub_config}" | sed -n "${boot_default_plus_1}p" | awk '{print $2}' | sed 's/\/boot\/vmlinuz-//')
echo "${version}"