#! /bin/sh
#
# rot		Logrotate script.
#		Used by other scripts to rotate log file(s).
#
# Usage:	adm/rot number-of-cycles logfile [logfile..]
#

if ! [ "$1" -gt 0 ] 2>/dev/null
then
	echo "Usage: rot number-of-cycles logfile [logfile..]" >&2
	exit 1
fi

NUM=$(($1 - 1))
shift
for FN in "$@"
do
	if ! [ -s "$FN" ]
	then
		continue
	fi

	C=$NUM
	while [ $C -gt 0 ]
	do
		PREV=$(($C - 1))
		if [ -f "$FN".$PREV ] && ! [ -f "$FN".$PREV.gz ]
		then
			gzip -f "$FN".$PREV
		fi
    		if [ -f "$FN".$PREV.gz ]
		then
    			mv -f "$FN".$PREV.gz "$FN".$C.gz
		fi
		C=$PREV
	done

	if [ -f "$FN" ]
	then
    		mv -f "$FN" "$FN".0
		touch "$FN"
	fi
done