pacrevert

pacrevert

#!/bin/bash

read -d $'\0' HELP <<-EOF
	Usage: ${0##*/} [-h|--help]
	       ${0##*/} [-l|--logfile <logfile>] { PACKAGE | - }

	Revert package upgrades from the most recent transaction.
	Specify which packages on the command line to limit which
	are downgraded, or use '-' to read package list from stdin.

	Options:
	  --logfile  Use an alternate logfile.
EOF

# Args
TEMP=$(getopt -o 'hl:' --longoptions 'help,logfile' -n "${0##*/}" -- "$@")
if [[ $? -ne 0 ]]; then
	echo "$HELP"
	exit 1
fi

eval set -- "$TEMP"
unset TEMP

while true; do
	case "$1" in
	--logfile)
		LOGFILE="$2"
		shift 2
		;;
	--help)
		echo "$HELP"
		exit
		;;
	--)
		shift
		break
		;;
	esac
done
LOGFILE="${LOGFILE:-$(pacconf logfile)}"

declare -a PACKAGES
while true; do
	case "$1" in
	"")
		break
		;;
	-)
		[[ -n "$EXTRA" ]] && break
		while read -r -a EXTRA; do
			PACKAGES+=("${EXTRA[@]}")
		done
		shift
		;;
	*)
		PACKAGES+=("$1")
		shift
		;;
	esac
done

# Patterns
PKGEXT="pkg.tar.*"
PTN='([[:alnum:]:.-]+)'
UPGRADE_PTN="s/$PTN \($PTN -> $PTN\)/\1 \2 \3/"
REMOVED_PTN="s/$PTN \($PTN\)/\1 \2/"

# Get the most recent transaction
paclast() {
	sed -n 'H;/transaction started$/h;${x;p}' "$LOGFILE"
}

# Find package w/ version in cache
pacfind() {
	PKG="$1" VER="$2"
	NAME="$PKG-$VER-*.$PKGEXT"
	find $(pacconf cachedir) -name "$NAME" | head -n1 |
		grep $ || echo "WARNING: '$PKG-$VER' not in cache" 1>&2
}

pacrevert() {
	local PKG OLDVER NEWVER
	paclast | 
	while read TIME CALLER TYPE INFO; do
		if [[ "$INFO" == "completed" ]]; then
			break
		fi

		if [[ "$CALLER" == "[ALPM]" ]]; then
			case "$TYPE" in
			upgraded)
				sed -E "$UPGRADE_PTN" <<< "$INFO"
				;;
			downgraded)
				sed -E "$UPGRADE_PTN" <<< "$INFO"
				;;
			removed)
				sed -E "$REMOVED_PTN" <<< "$INFO"
				;;
			*)
				continue
			esac 
		fi
	done |
	while read PKG OLDVER NEWVER; do
		if [[ ${#PACKAGES[@]} -gt 0 ]]; then
			printf "%s\n" "${PACKAGES[@]}" |
				grep -Fqx "$PKG" || {
				echo "WARNING: skipping package '$PKG'" 1>&2
				continue
			}
		fi
		pacfind "$PKG" "$OLDVER"
	done
}

paclast | paclog --caller=ALPM --logfile=-
pacrevert "$@" | pacman -U -