#! /bin/sh
# expov - expire obsolete overview entries

# =()<. ${NEWSCONFIG-@<NEWSCONFIG>@}>()=
. ${NEWSCONFIG-/usr/local/libexec/cnews/config}

PATH=$NEWSCTL/bin:$NEWSBIN/nov:$NEWSBIN:$NEWSPATH ; export PATH
umask $NEWSUMASK

lock LOCKoverview $$
trap "unlock LOCKoverview ; rm -f $NEWSCTL/active.ovt ; trap 0 ; exit" 0 1 2 15

cd $NEWSCTL
lock LOCK $$
cp active active.ovt
unlock LOCK

# the sort is an attempt to maximise locality of reference in the file system
sort active.ovt | tr . / |
	while read d max min rest
	do
		cd $NEWSARTS
		if test ! -d $d
		then
			continue
		fi
		cd $d
		o=$NEWSOV/$d
		if test ! -r $o/.overview
		then
			if test ! -d $o
			then
				case "$rest" in
				x*|=*)	;;	# not worth complaining
				*)	echo "$0: directory \`$o' does not exist" >&2 ;;
				esac
				continue
			fi
			touch $o/.overview
		fi
		if ls -f | expovguts $max $min $o/.overview
		then
			: okay
		else
			echo "$0: expovguts failed in $d" >&2
			echo "	...using fallback code" >&2

			# fallback
			# could use one less temporary if GNU sort didn't
			# have bugs in -o
			sort $o/.overview >$o/.sov
			ls | egrep '^[0-9]+$' | join -t'	' - $o/.sov |
							sort -n >$o/.nov
			mv $o/.nov $o/.overview
			rm -f $o/.sov
		fi
	done

# and the trap handles cleanup