install.brio-br

#!/bin/bash
# 'install.brio-br' - A script to install 'brio-br' and associated links to '/usr/local/bin' as root (default)
##
#########################
### Declare variables ###
#########################
##
APPL='install.brio-br'
APPLBR='brio-br'
BIN=${BIN:-/usr/local/bin}
BBRURL='https://raw.githubusercontent.com/DennisLfromGA/brunch-things/main/brio-br'
CWD="$(pwd)"
IBBRURL='https://raw.githubusercontent.com/DennisLfromGA/brunch-things/main/install.brio-br'
INSTRUCTIONS="
IMPORTANT: To initially download, install & run this script enter:

	cd /tmp &&\\
	curl -LO ${IBBRURL} &&\\
	sudo install -Dt /usr/local/bin -m 755 ${APPL} && ${BIN}/${APPL}

Once installed the script will autoupdate if needed when it's run.
"
PERM=${PERM:-755}
OPTIONS="\
Options:
	-h    Displays help message for options (this blurb)
	-i    Displays instructions for initial download, install and running this script
	-l    Lists installed files & links under ${BIN}
	-u    Displays usage for backup and restore
	-f    Force update of brio-br & install.brio-br
	-c    Check if installed versions of '${APPL}' & '${APPLBR}' are up-to-date
	-v    Displays the current version of '${APPL}'
	-V    Displays version number plus version history
"

SUDO=${SUDO:-sudo}
UPDATE="${UPDATE:-n}"
USAGE="
'${APPL}': A script to install '${APPLBR}' and associated links to '/usr/local/bin' as root (default)
${INSTRUCTIONS}
Will link: 'brio-b' & 'brio-backup'  to '${APPLBR}' which forces those scripts to run the 'backup'  option.
Will link: 'brio-r' & 'brio-restore' to '${APPLBR}' which forces those scripts to run the 'restore' option.

Usage: '${APPL}' [-h|-i|-l|-u|-f|-c|-v|-V] (see Help/Options)

Note: To replace the install PATH (default: /usr/local/bin) prepend '${APPL}' with BIN=your/path
      To replace the file permissions (default 755) prepend '${APPL}' with PERM=nnn
      To execute '${APPL}' as user '${USER}' instead of 'root' (default) prepend '${APPL}' with SUDO=' '

      (I.E.) BIN=~/bin PERM=775 SUDO=' ' ${APPL}
"
# VERSION format: "n.n.$(date +%Y%m%d%H%M)"
VERSION='3.1.0.202109111642'
VERHIST="\
${APPL}-3.1.0.202109111642 : Added option '-f' to force update of brio-br & install.brio-br
${APPL}-3.0.0.202109071554 : Added autoupdate feature for install.brio-br
${APPL}-2.0.2.202109061732 : Changed URLS from gists to a repo for install.brio-br & brio-br
${APPL}-2.0.1.202109061542 : Added option to force an update of brio-br
${APPL}-2.0.0.202109061536 : Added update check of both install.brio-br & brio-br
${APPL}-1.6.1.202109061244 : Made mostly minor cosmetic changes to display
${APPL}-1.6.0.202109061236 : Added 3rd digit to VERSION for minor tweaks
${APPL}-1.5.202109051624 : Added 'list files' to options
${APPL}-1.5.202109051624 + Misc. tweaks to functions, clarified file listing location, etc.
${APPL}-1.4.202109051455 : Minor tweak to 'valid responses' for instructions - duh!
${APPL}-1.3.202109051436 : Tweaked to include instructions option throughout
${APPL}-1.2.202109051325 : Added instructions to download, install & execute this script
${APPL}-1.1.202109051151 : Added raw link to download 'brio-br' and command-line options
${APPL}-1.0.202109041942 : Initial script to install 'brio-br' and associated links"
##
#######################
### Setup functions ###
#######################
##
## exit with exit code $1, spitting out message $@ to stderr
echo_e='/bin/echo -e'
error() {
	local ecode="${1}"
	shift
	${echo_e} "${*}" 1>&2
	exit "${ecode}"
}
##
check_for_opts() {
## Get command line parameters
	local OPTIND
	while getopts hoilufcvV OPT; do
		case ${OPT} in
			h|o) error 0 "${OPTIONS}";;
			i) error 0 "${INSTRUCTIONS}";;
			l) cd ${BIN} 1>/dev/null
				 echo; echo "File listing under ${BIN}:"
				 ls -li ${APPLBR} brio-b brio-backup  brio-r brio-restore ${APPL}
				 exit 0;;
			u) error 0 "${USAGE}";;
			c) check_versions; exit;;
			f) UPDATE=y; echo "Updates requested ...";;
			v) echo "${VERHIST}" | grep ${VERSION}; exit 0 ;;
			V) error 0 "VERSION:${VERSION}\n${VERHIST}" ;;
			\?) error 1 "${USAGE}\n${OPTIONS}";;
		esac
	done
	shift "$((OPTIND-1))"
	if [ "${#}" -gt 0 ]; then
		echo "${APPL}: invalid option -- ${1}"
		error 1 "${USAGE}\n${OPTIONS}"
	fi
}
##
check_versions() {
	cd /tmp 1>/dev/null
	if curl -sLO ${BBRURL} && diff -qw ${APPLBR} /usr/local/bin; then
		echo "Your installed version of '${APPLBR}' is up-to-date and good to go ..."
	else
		echo "Your installed version of '${APPLBR}' is missing or NOT up-to-date, update requested ..."
		UPDATE=b
	fi
	if curl -sLO ${IBBRURL} && diff -qw ${APPL} /usr/local/bin; then
		echo "Your installed version of '${APPL}' is up-to-date and good to go ..."
	else
		echo "Your installed version of '${APPL}' is missing or NOT up-to-date, an update will be done now ..."
		UPDATE=i
	fi
	echo
}
##
ask_nicely() {
	local REPLY=''
	if [ "${UPDATE}" = "b" -o "${UPDATE}" = "y" ]; then
		echo "Install '${APPLBR}' and associated links to '${BIN}' as root (default) [Ysilhq] ?"
		read -s -n 1 -p "Enter 'y' to install, 'i' for installation instructions, 'l' to list, 'c' check versions, 'h' for help, or 'q' to quit ? "
		echo
		case ${REPLY:-Y} in 
		[yY])
			echo; echo "Installing '${APPLBR}' and links to ${BIN} ..."
			;;
		[iI])
			error 0 "${INSTRUCTIONS}"
			;;
		[lL])
			cd ${BIN} 1>/dev/null
			echo; echo "File listing under ${BIN}:"
			ls -li ${APPLBR} brio-b brio-backup  brio-r brio-restore ${APPL}
			echo; ask_nicely
			;;
		[hH]|[oO])
			echo "${OPTIONS}"
			ask_nicely
			;;
		[uU])
			echo "${USAGE}"
			ask_nicely
			;;
		[cC])
			check_versions
			ask_nicely
			;;
		[qQ]|[aA])
			echo; error 0 "Aborting/Quitting ..."
			;;
		v)
			echo; echo "${VERHIST}" | grep ${VERSION}
			echo; ask_nicely
		;;
		V)
			echo; echo "VERSION:${VERSION}"
			echo "${VERHIST}"
			echo; ask_nicely
		;;
		*)
			echo "Sorry, valid responses are:"
			echo; echo "      'y' to install, 'i' for installation instructions, 'l' to list, 'h' for help, or 'q' to quit."
			echo; ask_nicely
			;;
		esac
	else
		error 0 "No updates needed or requested, exiting ..."
	fi
}
##
install_brio-br() {
	cd /tmp 1>/dev/null
	echo "Downloading '${APPLBR}' ..."
	curl -sLO --progress-bar ${BBRURL} || \
		error 2 "Cannot download '${APPLBR}'"
	echo "Removing installed '${APPLBR}', if any ..."
	${SUDO} rm -f ${BIN}/${APPLBR} 2>/dev/null || \
		error 2 "Cannot remove existing '${APPLBR}'"
	echo "Installing an updated '${APPLBR}' ..."
	${SUDO} install -Dt ${BIN} -m 755 /tmp/${APPLBR} || \
		error 3 "Cannot install '${APPLBR}'"
	## Using hard links to avoid 'nosymfollow'
	echo "Linking apps to '${APPLBR}' ..."
	${SUDO} ln -fT ${BIN}/${APPLBR} ${BIN}/brio-b || \
		error 4 "Cannot link '${APPLBR}' as 'brio-b'"
	${SUDO} ln -fT ${BIN}/${APPLBR} ${BIN}/brio-backup || \
		error 4 "Cannot link '${APPLBR}' as 'brio-backup'"
	${SUDO} ln -fT ${BIN}/${APPLBR} ${BIN}/brio-r || \
		error 4 "Cannot link '${APPLBR}' as 'brio-r'"
	${SUDO} ln -fT ${BIN}/${APPLBR} ${BIN}/brio-restore || \
		error 4 "Cannot link '${APPLBR}' as 'brio-restore'"
}
##
install_installer() {
	if [ "${UPDATE}" = "i" -o "${UPDATE}" = "y" ]; then
		cd /tmp 1>/dev/null
		echo "Downloading '${APPL}' ..."
		curl -sLO --progress-bar ${IBBRURL} || \
			error 2 "Cannot download '${APPL}'"
		echo "Removing installed '${APPL}', if any ..."
		${SUDO} rm -f ${BIN}/${APPL} 2>/dev/null ||
			error 2 "Cannot remove existing '${APPL}'"
		echo "Installing an updated '${APPL}' ..."
		sudo install -Dt /usr/local/bin -m 755 ${APPL} || \
			error 3 "Cannot install '${APPL}'"
		echo "'${APPL}' updated and installed, now launching it ..."
		echo; exec ${BIN}/${APPL} || \
			error 4 "Cannot execute '${APPL}'"
		exit
	fi
}
##
###########################
### Main section ###
###########################
##
if [ $(id -u) -eq 0 ]; then
	echo
	echo "ERROR: ${APPL} must NOT be run as root!"
	error 1 "${USAGE}"
fi
check_for_opts "${@}"
check_versions
ask_nicely
install_brio-br
install_installer
cd ${CWD} 1>/dev/null
error 0 "'${APPL}' successful, exiting."