kernel-utils.sh

#!/bin/bash
set -eu

function current_kernel_version() {
  uname -r | sed -r 's/-[a-z]+//'
}

function kernels() {
  dpkg -l linux-{image,headers,modules,hwe,modules-extra}-"[0-9]*" | awk '/ii/{print $2}'
}

function current_kernel() {
  kernels | grep "$(current_kernel_version)"
}

function unused_kernels() {
  kernels | grep -v "$(current_kernel_version)"
}

function remove_unused_kernels() {
  sudo apt-get purge $(unused_kernels)
  sudo apt autoremove
}

function update_kernel() {
  sudo apt-get install linux-generic
  sudo apt autoremove
}

function print_usage() {
  echo "USAGE: $0 [cmd]"
  echo
  echo "  version - version of the current linux kernel"
  echo "  current - current linux kernel"
  echo "  unused  - unused linux kernels"
  echo "  remove_unused  - delete unused linux kernels"
  echo "  update  - update linux kernel"
}

function main() {
  if [ -z "${1-}" ]; then
    print_usage
    return 0
  fi

  case "$1" in
    -v|v|version)
        current_kernel_version
        ;;
    -c|c|current)
        current_kernel
        ;;
    -u|u|unused)
        unused_kernels
        ;;
    -rm|rm|remove_unused)
        remove_unused_kernels
        ;;
    update)
        update_kernel
        ;;
    *)
        print_usage
        return 1
        ;;
  esac
}

if [[ "${BASH_SOURCE[0]}" == "${0}" ]]; then
    main $@
fi