#!/usr/bin/env bash

# One-Liner command with sudo
#sudo sed -i 's/^GRUB_TIMEOUT=.*/GRUB_TIMEOUT=1/g' /etc/default/grub && sudo update-grub

path_to_grub=/etc/default/grub

if test ! -w ${path_to_grub}; then
  echo "no permission, run as root"
  exit 1
fi

if ! (grep '^GRUB_HIDDEN_TIMEOUT' ${path_to_grub} &> /dev/null); then
  sed -i 's/^GRUB_TIMEOUT=.*/GRUB_TIMEOUT=1/g' ${path_to_grub} \
  && (update-grub || echo echo "Something went wrong with update-grub") \
  || echo "Something went wrong with sed ${path_to_grub}"
else
  echo "Does not make sense if GRUB_HIDDEN_TIMEOUT is set"
  exit 1
fi