#!/bin/sh
# replace *i686.rpm with given *i586.rpm
#
# Usage:
# $0 ../DVD1/ RPMS/i586/pkg-1.0.i586.rpm
# will replace ../DVD1/Packages/pkg-1.0.i686 with given pkg-1.0.i586
# by removing the former and hardlinking the latter
#

# PACKAGES=/media/IODATA40G/DVD1/Packages/
PACKAGES=
test -d "$1"/CentOS   && PACKAGES="$1"/CentOS
test -d "$1"/Packages && PACKAGES="$1"/Packages
test -d "$1"/RPMS     && PACKAGES="$1"/RPMS
if [ -z "$PACKAGES" ]; then echo No $1/Packages exist. 2>&1; exit 1; fi
shift

# arg1: "pkg"
# return pkg-1.0.i686.rpm, or ""
# find corresponding .i686.rpm in $PACKAGES/
get_i686_pkg () {
	N="$1"
	#linear search is slow
	find $PACKAGES -type f -name $N'*.rpm' |
	while read i686_rpm; do
		N6=`rpm -q --qf '%{N}' -p $i686_rpm`
		if [ "$N" = "$N6" ]; then
			echo FOUND $i686_rpm >&2;
			echo $i686_rpm
			return
		fi
	done
	echo ""
	return 1
}

CTMP=/tmp/rep$$
trap "rm $CTMP" 0 1 2 15
cp /dev/null $CTMP

for i586_rpm in "$@"; do
	## get NAME of rpm
	N=`rpm -q --qf '%{N}' -p $i586_rpm`
	echo Finding $N
	## find corresponding .i686.rpm in $PACKAGES/
	i686_rpm=`get_i686_pkg $N`
	if [ -z "$i686_rpm" ]; then
		echo No corresponding $N.i686.rpm found. >&2
	fi
	if [ -n "$i686_rpm" ]; then
		# Usually "rm"ing is right, but 
		# if $i686_rpm was the same file as $i586_rpm, don't rm nor ln.
		if [ x`stat -c %d:%i $i586_rpm` != x`stat -c %d:%i $i686_rpm` ]; then
			echo rm "$i686_rpm" >> $CTMP
			if [ x`stat -c %d $i586_rpm` = x`stat -c %d $PACKAGES` ]; then
				echo ln $i586_rpm $PACKAGES >> $CTMP
			else
				echo cp -p $i586_rpm $PACKAGES >> $CTMP
			fi
		else
			:
		fi
	fi
done
echo '>>>>> preparing to do:'
cat $CTMP
echo '<<<<<'
echo -n "Do it? [y/N] "; read yn;
if [ "$yn" = "y" ]; then
	sh -x $CTMP
fi
#$CTMP erased by trap