Unfa.ir

—

I’ve been working with OpenWRT on linksys NSLU2 lately for some projects that I ran into a strange error while using the package manager OPKG.

as you may know OpenWrt, the latest version of this project is called kamikaze (8.09). the older one was called “White Russian” (as the big lebowsky’s favorite drink). some interesting naming of these distributions is that they are both Alcohol Drink mix’s. and also IPKG is OPKG in here!

Anyways I’ve ran into this problem when trying to install some packages using “opkg install <package> or <file>”.

the output would be something like:

Configuring <Package>

//usr/lib/opkg/info/<Package>.postinst: line 2: update-alternatives: not found

postinst script returned status 127

The reason for this error is that somehow update-alternatives is not availble in OpenWrt or maybe in this version.

So the solution would be to add this file in the Path it should be,

you need to use Vi or ,as my favorite, Nano to do so.

nano /opt/bin/update-alternatives

and paste this into the file:

#!/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

update-alternatives --remove
update-alternatives --help

is the link pointing to the provided path (ie. /usr/bin/foo).
is the name in $ad/alternatives (ie. foo)

is the name referred to (ie. /usr/bin/foo-extra-spiffy)

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

"
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
"
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