#!/bin/sh

# The default Debian ntp.conf enables logging of various statistics to
# the /var/log/ntpstats directory.  The daemon automatically changes
# to a new datestamped set of files at midnight, so all we need to do
# is delete old ones, and compress the ones we're keeping so disk
# usage is controlled.

statsdir=$(cat /etc/ntp.conf | grep -v '^#' | sed -nr 's/^statsdir[[:space:]]+([^[:space:]]+).*$/\1/p')

if [ -n "$statsdir" ] && [ -d "$statsdir" ]; then
	# only keep a week's depth of these. Delete only files exactly
	# within the directory and do not descend into subdirectories
	# to avoid security risks on platforms where find is not using
	# fts-library.
	find "$statsdir" -maxdepth 1 -type f -mtime +7 -delete

	# compress whatever is left to save space but make sure to really
	# do it only in the expected directory.
	cd "$statsdir" || exit 1
	ls -d -- *stats.???????? > /dev/null 2>&1
	if [ $? -eq 0 ]; then
		# Note that gzip won't compress the file names that
		# are hard links to the live/current files, so this
		# compresses yesterday and previous, leaving the live
		# log alone.  We suppress the warnings gzip issues
		# about not compressing the linked file.
		gzip --best --quiet -- *stats.????????
		return=$?
		case $return in
		    2)
			exit 0			# squash all warnings
			;;
		    *)
			exit $return	 	# but let real errors through
			;;
		esac
	fi
fi