#!/bin/sh
# install lynx.cfg, ensuring the old config-file is saved to a unique file,
# and prepending customizations to the newly-installed file.
#
# $1 = install program
# $2 = file to install
# $3 = where to install it
PRG="$1"
SRC=$2
DST=$3

if test -f "$DST" ; then
	echo "** checking if you have customized $DST"
	OLD=lynx-cfg.old
	NEW=lynx-cfg.new
	TST=lynx-cfg.tst
	TMP=lynx-cfg.tmp
	trap "rm -f $OLD $NEW $TST $TMP; exit 9" 1 2 5 15
	rm -f $OLD $NEW $TST $TMP

	# Make a list of the settings which are in the original lynx.cfg
	# Do not keep the user's HELPFILE setting since we modify that in
	# a different makefile rule.
	egrep '^[ 	]*[A-Za-z]' $SRC |sed -e 's/^[ 	]*HELPFILE:.*/HELPFILE:/' >$TMP
	egrep '^[ 	]*[A-Za-z]' $SRC |fgrep -v -f $TMP >$OLD
	egrep '^[ 	]*[A-Za-z]' $DST |fgrep -v -f $TMP >$TST

	if test -s $TST ; then
		cat >$TMP <<EOF
## The following lines were saved from your previous configuration.

EOF
		cat $TST >>$TMP
		cat $SRC >$NEW
		cat $TMP >>$NEW

		# See if we have saved this information before (ignoring the
		# HELPFILE line).
		if cmp -s $NEW $OLD
		then
			echo "... installed $DST would not be changed"
		else
			NUM=1
			while test -f ${DST}-${NUM}
			do
				if cmp -s $NEW ${DST}-${NUM}
				then
					break
				fi
				NUM=`expr $NUM + 1`
			done
			if test ! -f ${DST}-${NUM}
			then
				echo "... saving old config as ${DST}-${NUM}"
				mv $DST ${DST}-${NUM} || exit 1
			fi
			echo "** installing $NEW as $DST"
			eval $PRG $NEW $DST || exit 1
		fi
	else
		echo "... no customizations found"
		echo "** installing $SRC as $DST"
		eval $PRG $SRC $DST || exit 1
	fi
	rm -f $SKIP $OLD $NEW $TST $TMP
elif cmp -s $SRC $DST
then
	echo "... installed $DST would not be changed"
else
	echo "** installing $SRC as $DST"
	eval $PRG $SRC $DST || exit 1
fi