Ubuntu update/upgrade scripts

ubuntu_update.sh

#!/usr/bin/env bash
##########################################################################################################
# 
# Ubuntu OS Patching
#
# VN
# v1.0 202010
#
# Upgrade packages: $0 -uU
# Fix dependency issues: $0 -d
# Check packages to be installed: $0 -c
# Cleanup cache of old packages: $0 -C
# Delete obsolete packages: $0 -D
#
# References:
# https://askubuntu.com/questions/81585/what-is-dist-upgrade-and-why-does-it-upgrade-more-than-upgrade
#
##########################################################################################################

##############
# FUNCTIONS
##############
# --------------------------------------------------------------------------- #

function msg()
{
    echo "(I) " $*
}

# --------------------------------------------------------------------------- #

function err()
{
    echo "(E) " $*
    exit 1
}

# --------------------------------------------------------------------------- #

function debug()
{
    if [ $DEBUG -gt 0 ]; then
        echo "(D) " $*
    fi
}

# --------------------------------------------------------------------------- #

function update()
{
	apt-get update
}

# --------------------------------------------------------------------------- #

function upgradeAll()
{
	apt-get upgrade -y
}

# --------------------------------------------------------------------------- #

#intelligently handles changing dependencies with new versions of packages; ref https://askubuntu.com/questions/81585/what-is-dist-upgrade-and-why-does-it-upgrade-more-than-upgrade
function distupgrade()
{
        apt-get dist-upgrade -y
}

# --------------------------------------------------------------------------- #

function check()
{
	/usr/lib/update-notifier/apt-check --human-readable
}

# --------------------------------------------------------------------------- #

function clean()
{
	apt-get clean
}

# --------------------------------------------------------------------------- #

#remove packages that were automatically installed to satisfy dependencies for other packages and are now no longer needed
function deleteobsolete()
{
        apt-get autoremove -y
}

# --------------------------------------------------------------------------- #


function usage() {
            echo "Usage: $0 [-h] [-uUdDcC]"
            echo -e "$0 \n [-h]: Prints this help message\n [-u]: Update the package list \n [-U]: Upgrade all packages \n [-d]: handle changing dependencies with new versions of packages \n [-D]: uninstall obsolete packages\n [-c]: check number of packages to upgrade\n [-C]: clean the apt cache"
            exit 1
}

# --------------------------------------------------------------------------- #
# --------------------------------------------------------------------------- #

#########
# MAIN
#########

#script needs elevated privileges
if [ ${UID} != 0 ];then
	err "script should be run as root or sudo"
fi

#process input
while getopts ":huUcCdD" opt; do
  case ${opt} in
    u)
            option="update"
            echo -e "\ngiven option is $option"
	    update
	    #check
      ;;
    U)
            option="upgrade"
            echo -e "\ngiven option is $option"
	    check
	    upgradeAll
      ;;
    c)
            option="check"
            echo -e "\ngiven option is $option"
	    check
      ;;
    C)
	    option="clean"
            echo -e "\ngiven option is $option"
	    clean
      ;;
    d)
	    option="distupgrade"
            echo -e "\ngiven option is $option"
	    distupgrade
      ;;
    D)
            option="deleteobsolete"
            echo -e "\ngiven option is $option"
            deleteobsolete
      ;;
    h | *)
            #echo "Incorrect syntax"
            usage
      ;;
  esac
done
shift $((OPTIND -1))

if [ -z "${option}" ];then
    echo "ERROR: Any one option mandatory!"
    usage
fi

echo

ubuntu_upgrade.sh

#!/bin/bash

########################
# Ubuntu Upgrade Script
########################

#ensure system is updated
apt update
apt upgrade -y

#handles changing dependencies with new versions of packages
apt dist-upgrade

#remove packages that were automatically installed to satisfy dependencies for other packages and are now no longer needed
apt-get autoremove

#manage release upgrades
apt install -y update-manager-core

#if the new OS is listed in http://changelogs.ubuntu.com/meta-release-lts, upgrade will work; or else to upgrade with "-d" option to force upgrade to dev release
#silent-upgrade ("yes" to all prompts)
do-release-upgrade -f DistUpgradeViewNonInteractive