#!/bin/sh

# check-kernel #VERSION#

verwendung() {
  >&2 echo 'check-kernel checks if the installed kernel is currently running'
  >&2 echo ''
  >&2 echo 'Usage: sendmailadvanced [OPTIONS]'
  >&2 echo '  -r,--reboot     reboot system if installed kernel is not yet running'
  >&2 echo \
'#HELPTEXT#    #'
  exit 1
}

eval set -- "$(
  getopt -o eh:i:st \
    --long encrypt \
    --long help \
    --long version \
    -n "$(basename "$0")" -- "$@" \
    || echo verwendung
)"

reboot=false
while true; do
  case "$1" in
    -r|--reboot)
      shift
      reboot=true
    ;;
    --help)
      verwendung 0
      ;;
    --version)
      echo '#VERSION#'
      exit 0
      ;;
    --)
      shift
      break
    ;;
    *)
      >&2 echo "FEHLER: Verstehe Option \"$1\" doch nicht! Ich beende."
      verwendung
    ;;
  esac
  shift
done


if which pacman >/dev/null 2>&1; then
  # arch linux
  running=$(
    uname -r | \
      sed '
        s|-ARCH$||
      '
  )
  installed=$(
    pacman -Q linux | \
      cut -d' ' -f2
  )
elif which apt >/dev/null 2>&1; then
  # debian
  running=$(
    uname -r
  )
  installed=$(
    dpkg-query -W 'linux-image-*-?86' | \
      cut -f1 | \
      sed '
        s|^linux-image-||
      ' | \
      sort -V | \
      tail -n1
  )
else
  >&2 printf 'Cannot determin installed kernel.\n'
  exit 2
fi

if [ "${running}" = "${installed}" ]; then
  >&2 printf 'The installed kernel (%s) is currently running.\n' \
    "${installed}"
  exit 0
else
  >&2 printf 'The installed (%s) and running kernel (%s) differ.\n' \
    "${installed}" \
    "${running}"
  exit 1
fi