Rename /usr/lib/dpkg/maintscript-helper in /usr/bin/dpkg-maintscript-helper

It is a public interface even if working around known limitations.

1 files changed, 256 insertions, 0 deletions

diff --git a/scripts/dpkg-maintscript-helper.sh b/scripts/dpkg-maintscript-helper.sh
new file mode 100755
index 000000000..db7ac3a18
--- /dev/null
+++ b/scripts/dpkg-maintscript-helper.sh
@@ -0,0 +1,256 @@
+#!/bin/sh
+#
+# Copyright © 2010 Raphaël Hertzog <hertzog@debian.org>
+# Copyright © 2008 Joey Hess <joeyh@debian.org>
+# Copyright © 2007 Guillem Jover (modifications on wiki.debian.org)
+# Copyright © 2005 Scott James Remnant (original implementation on www.dpkg.org)
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# The conffile related functions are inspired by
+# http://wiki.debian.org/DpkgConffileHandling
+
+# This script is documented in dpkg-maintscript-helper(1)
+
+##
+## Functions to remove an obsolete conffile during upgrade
+##
+rm_conffile() {
+	local CONFFILE="$1"
+	local LASTVERSION="$2"
+	local PACKAGE="$3"
+	if [ "$PACKAGE" = "--" -o -z "$PACKAGE" ]; then
+		PACKAGE="$DPKG_MAINTSCRIPT_PACKAGE"
+	fi
+	# Skip remaining parameters up to --
+	while [ "$1" != "--" -a "$1" != "" ]; do shift; done
+	shift
+
+	[ -n "$PACKAGE" ] || error "couldn't identify the package"
+	[ -n "$1" ] || error "maintainer script parameters are missing"
+	[ -n "$DPKG_MAINTSCRIPT_NAME" ] || \
+		error "environment variable DPKG_MAINTSCRIPT_NAME is required"
+
+	debug "Executing $0 rm_conffile in $DPKG_MAINTSCRIPT_NAME "\
+	      "of $DPKG_MAINTSCRIPT_PACKAGE"
+	debug "CONFFILE=$CONFFILE PACKAGE=$PACKAGE "\
+	      "LASTVERSION=$LASTVERSION ACTION=$1 PARAM=$2"
+	case "$DPKG_MAINTSCRIPT_NAME" in
+	preinst)
+		if [ "$1" = "install" -o "$1" = "upgrade" ] &&
+		   dpkg --compare-versions "$2" le-nl "$LASTVERSION"; then
+			prepare_rm_conffile "$CONFFILE" "$PACKAGE"
+		fi
+		;;
+	postinst)
+		if [ "$1" = "configure" ] &&
+		   dpkg --compare-versions "$2" le-nl "$LASTVERSION"; then
+			finish_rm_conffile $CONFFILE
+		fi
+		;;
+	postrm)
+		if [ "$1" = "purge" ]; then
+			rm -f "$CONFFILE.dpkg-bak" "$CONFFILE.dpkg-remove"
+		fi
+		if [ "$1" = "abort-install" -o "$1" = "abort-upgrade" ] &&
+		   dpkg --compare-versions "$2" le-nl "$LASTVERSION"; then
+			abort_rm_conffile "$CONFFILE"
+		fi
+		;;
+	*)
+		debug "$0 rm_conffile not required in $DPKG_MAINTSCRIPT_NAME"
+		;;
+	esac
+}
+
+prepare_rm_conffile() {
+	local CONFFILE="$1"
+	local PACKAGE="$2"
+
+	[ -e "$CONFFILE" ] || return 0
+
+	local md5sum="$(md5sum $CONFFILE | sed -e 's/ .*//')"
+	local old_md5sum="$(dpkg-query -W -f='${Conffiles}' $PACKAGE | \
+		sed -n -e "\' $CONFFILE ' { s/ obsolete$//; s/.* //; p }")"
+	if [ "$md5sum" != "$old_md5sum" ]; then
+		echo "Obsolete conffile $CONFFILE has been modified by you."
+		echo "Saving as $CONFFILE.dpkg-bak ..."
+		mv -f "$CONFFILE" "$CONFFILE.dpkg-bak"
+	else
+		echo "Moving obsolete conffile $CONFFILE out of the way..."
+		mv -f "$CONFFILE" "$CONFFILE.dpkg-remove"
+	fi
+}
+
+finish_rm_conffile() {
+	local CONFFILE="$1"
+
+	if [ -e "$CONFFILE.dpkg-remove" ]; then
+		echo "Removing obsolete conffile $CONFFILE ..."
+		rm -f "$CONFFILE.dpkg-remove"
+	fi
+}
+
+abort_rm_conffile() {
+	local CONFFILE="$1"
+
+	if [ -e "$CONFFILE.dpkg-remove" ]; then
+		echo "Reinstalling $CONFFILE that was moved away"
+		mv "$CONFFILE.dpkg-remove" "$CONFFILE"
+	fi
+	if [ -e "$CONFFILE.dpkg-bak" ]; then
+		echo "Reinstalling $CONFFILE that was backupped"
+		mv "$CONFFILE.dpkg-bak" "$CONFFILE"
+	fi
+}
+
+##
+## Functions to rename a conffile during upgrade
+##
+mv_conffile() {
+	local OLDCONFFILE="$1"
+	local NEWCONFFILE="$2"
+	local LASTVERSION="$3"
+	local PACKAGE="$4"
+	if [ "$PACKAGE" = "--" -o -z "$PACKAGE" ]; then
+		PACKAGE="$DPKG_MAINTSCRIPT_PACKAGE"
+	fi
+	# Skip remaining parameters up to --
+	while [ "$1" != "--" -a "$1" != "" ]; do shift; done
+	shift
+
+	[ -n "$PACKAGE" ] || error "couldn't identify the package"
+	[ -n "$1" ] || error "maintainer script parameters are missing"
+	[ -n "$DPKG_MAINTSCRIPT_NAME" ] || \
+		error "environment variable DPKG_MAINTSCRIPT_NAME is required"
+
+	debug "Executing $0 mv_conffile in $DPKG_MAINTSCRIPT_NAME "\
+	      "of $DPKG_MAINTSCRIPT_PACKAGE"
+	debug "CONFFILE=$OLDCONFFILE -> $NEWCONFFILE PACKAGE=$PACKAGE "\
+	      "LASTVERSION=$LASTVERSION ACTION=$1 PARAM=$2"
+	case "$DPKG_MAINTSCRIPT_NAME" in
+	preinst)
+		if [ "$1" = "install" -o "$1" = "upgrade" ] &&
+		   dpkg --compare-versions "$2" le-nl "$LASTVERSION"; then
+			prepare_mv_conffile "$OLDCONFFILE" "$PACKAGE"
+		fi
+		;;
+	postinst)
+		if [ "$1" = "configure" ] &&
+		   dpkg --compare-versions "$2" le-nl "$LASTVERSION"; then
+			finish_mv_conffile "$OLDCONFFILE" "$NEWCONFFILE"
+		fi
+		;;
+	postrm)
+		if [ "$1" = "abort-install" -o "$1" = "abort-upgrade" ] &&
+		   dpkg --compare-versions "$2" le-nl "$LASTVERSION"; then
+			abort_rm_conffile "$OLDCONFFILE"
+		fi
+		;;
+	*)
+		debug "$0 mv_conffile not required in $DPKG_MAINTSCRIPT_NAME"
+		;;
+	esac
+}
+
+prepare_mv_conffile() {
+	local CONFFILE="$1"
+	local PACKAGE="$2"
+
+	[ -e "$CONFFILE" ] || return 0
+
+	local md5sum="$(md5sum $CONFFILE | sed -e 's/ .*//')"
+	local old_md5sum="$(dpkg-query -W -f='${Conffiles}' $PACKAGE | \
+		sed -n -e "\' $CONFFILE ' { s/ obsolete$//; s/.* //; p }")"
+	if [ "$md5sum" = "$old_md5sum" ]; then
+		mv -f "$CONFFILE" "$CONFFILE.dpkg-remove"
+	fi
+}
+
+finish_mv_conffile() {
+	local OLDCONFFILE="$1"
+	local NEWCONFFILE="$2"
+
+	rm -f $OLDCONFFILE.dpkg-remove
+
+	[ -e "$OLDCONFFILE" ] || return 0
+
+	echo "Preserving user changes to $NEWCONFFILE (renamed from $OLDCONFFILE)..."
+	mv -f "$NEWCONFFILE" "$NEWCONFFILE.dpkg-new"
+	mv -f "$OLDCONFFILE" "$NEWCONFFILE"
+}
+
+abort_mv_conffile() {
+	local CONFFILE="$1"
+
+	if [ -e "$CONFFILE.dpkg-remove" ]; then
+		echo "Reinstalling $CONFFILE that was moved away"
+		mv "$CONFFILE.dpkg-remove" "$CONFFILE"
+	fi
+}
+
+# Common functions
+debug() {
+	if [ -n "$DPKG_DEBUG" ]; then
+		echo "DEBUG: $PROGNAME: $1" >&2
+	fi
+}
+
+error() {
+	echo "ERROR: $PROGNAME: $1" >&2
+	exit 1
+}
+
+usage() {
+	cat <<END
+Syntax: $0 <command> [<parameters>] -- <maintainer script parameters>
+
+Commands and parameters:
+
+  rm_conffile <conffile> <last-version> [<package>]
+	Remove obsolete conffile.
+	Must be called in preinst, postinst and postrm.
+
+  mv_conffile <old-conf> <new-conf> <last-version> [<package>]
+	Rename a conffile.
+	Must be called in preinst, postinst and postrm.
+
+  help
+	Display this usage information.
+END
+}
+
+# Main code
+set -e
+
+PROGNAME=$(basename $0)
+command="$1"
+shift
+
+case "$command" in
+rm_conffile)
+	rm_conffile "$@"
+	;;
+mv_conffile)
+	mv_conffile "$@"
+	;;
+--help|help|-?|-h)
+	usage
+	;;
+*)
+	usage
+	exit 1
+esac
+
+exit 0