diff options
Diffstat (limited to 'update-alternatives')
-rwxr-xr-x | update-alternatives | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/update-alternatives b/update-alternatives new file mode 100755 index 0000000..a403202 --- /dev/null +++ b/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="$IPKG_OFFLINE_ROOT/usr/lib/ipkg/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=$IPKG_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 $path | sed 's|/\+|/|g'` + + # This is a bad hack, but I haven't thought of a cleaner solution yet... + [ -n "$IPKG_OFFLINE_ROOT" ] && path=`echo $path | sed "s|^$IPKG_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 $path | sed 's|/\+|/|g'` + + # This is a bad hack, but I haven't thought of a cleaner solution yet... + [ -n "$IPKG_OFFLINE_ROOT" ] && path=`echo $path | sed "s|^$IPKG_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 |