1 files changed, 189 insertions, 0 deletions
diff --git a/utils/update-alternatives b/utils/update-alternatives
new file mode 100755
index 0000000..4983e19
--- /dev/null
+++ b/utils/update-alternatives
@@ -0,0 +1,189 @@
+#!/bin/sh
+# update-alternatives
+#
+# Copyright (C) 2001 Carl D. Worth
+#
+# This program was inspired by the Debian update-alternatives program
+# which is Copyright (C) 1995 Ian Jackson. This version of
+# update-alternatives is command-line compatible with Debian's for a
+# subset of the options, (only --install, --remove, and --help)
+#
+# 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, 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.
+
+set -e
+
+# admin dir
+ad="$OPKG_OFFLINE_ROOT/usr/lib/opkg/alternatives"
+
+usage() {
+	echo "update-alternatives: $*
+
+Usage: update-alternatives --install <link> <name> <path> <priority>
+       update-alternatives --remove <name> <path>
+       update-alternatives --help
+<link> is the link pointing to the provided path (ie. /usr/bin/foo).
+<name> is the name in $ad/alternatives (ie. foo)
+<path> is the name referred to (ie. /usr/bin/foo-extra-spiffy)
+<priority> is an integer; options with higher numbers are chosen.
+" >&2
+	exit 2
+}
+
+quit() {
+	echo "update-alternatives: $*" >&2
+	exit 2
+}
+
+register_alt() {
+	[ $# -lt 2 ] && return 1
+	local name="$1"
+	local link="$2"
+
+	if [ ! -d $ad ]; then
+		mkdir -p $ad
+	fi
+
+	if [ -e "$ad/$name" ]; then
+		local olink=`head -n 1 $ad/$name`
+		if [ "$link" != "$olink" ]; then
+			echo "update-alternatives: Error: cannot register alternative $name to $link since it is already registered to $olink" >&2
+			return 1
+		fi
+	else
+		echo "$link" > "$ad/$name"
+	fi
+
+	return 0
+}
+
+protect_slashes() {
+	sed -e 's/\//\\\//g'
+}
+
+remove_alt() {
+	[ $# -lt 2 ] && return 1
+	local name="$1"
+	local path="$2"
+	
+	[ ! -f $ad/$name ] && return 0
+
+	path=`echo $path | protect_slashes`
+	sed -ne "/^$path\>.*/!p" $ad/$name > $ad/$name.new
+	mv $ad/$name.new $ad/$name
+}
+
+add_alt() {
+	[ $# -lt 3 ] && return 1
+	local name="$1"
+	local path="$2"
+	local priority="$3"
+	remove_alt $name $path
+	echo "$path $priority" >> $ad/$name
+}
+
+find_best_alt() {
+	[ $# -lt 1 ] && return 1
+	[ ! -f $ad/$name ] && return 0
+
+	link=$OPKG_OFFLINE_ROOT/`head -n 1 $ad/$name`
+
+##	path=`sed -ne "1!p" $ad/$name | sort -nr -k2 | head -1 | sed 's/ .*//'`
+## busybox safe:
+	path=`sed -ne "1!p" $ad/$name | sed -e "s/\(.*\) \(.*\)/\2 \1/g" | sort -nr | head -n 1 | sed 's/[^ ]* //'`
+	if [ -z "$path" ]; then
+		echo "update-alternatives: removing $link as no more alternatives exist for it"
+		rm $ad/$name
+		if [ -L $link ]; then
+			rm $link
+		fi
+		return 0
+	fi
+
+	if [ ! -e $link -o -L $link ]; then
+		local link_dir=`dirname $link`
+		if [ ! -d $link_dir ]; then
+			mkdir -p $link_dir
+		fi
+		ln -sf $path $link
+		echo "update-alternatives: Linking $link to $path"
+	else
+		echo "update-alternatives: Error: not linking $link to $path since $link exists and is not a link"
+		return 1
+	fi
+
+	return 0
+}
+
+do_install() {
+	if [ $# -lt 4 ]; then
+		usage "--install needs <link> <name> <path> <priority>"
+	fi
+	local link="$1"
+	local name="$2"
+	local path="$3"
+	local priority="$4"
+
+	path=`echo $path | sed 's|/\+|/|g'`
+
+	# This is a bad hack, but I haven't thought of a cleaner solution yet...
+	[ -n "$OPKG_OFFLINE_ROOT" ] && path=`echo $path | sed "s|^$OPKG_OFFLINE_ROOT/*|/|"`
+
+	register_alt $name $link
+	add_alt $name $path $priority
+	find_best_alt $name
+}
+
+do_remove() {
+       if [ $# -lt 2 ]; then
+		usage "--remove needs <name> <path>"
+	fi	
+	local name="$1"
+	local path="$2"
+
+	path=`echo $path | sed 's|/\+|/|g'`
+
+	# This is a bad hack, but I haven't thought of a cleaner solution yet...
+	[ -n "$OPKG_OFFLINE_ROOT" ] && path=`echo $path | sed "s|^$OPKG_OFFLINE_ROOT/*|/|"`
+
+	remove_alt $name $path
+	find_best_alt $name
+}
+
+###
+# update-alternatives "main"
+###
+
+while [ $# -gt 0 ]; do
+	arg="$1"
+	shift
+
+	case $arg in
+	--help)
+		usage "help:"
+		exit 0
+		;;
+	--install)
+		do_install $*
+		exit $?
+		;;
+	--remove)
+		do_remove $*
+		exit $?
+		;;
+	*)
+		usage "unknown argument \`$arg'"
+		;;
+	esac
+done
+
+usage "at least one of --install or --remove must appear"
+
+exit 0