#! /bin/sh
set -e

# check if we run on battery and if so then don't run
if which on_ac_power >/dev/null 2>&1; then
	ON_BATTERY=0
	on_ac_power >/dev/null 2>&1 || ON_BATTERY=$?
	if [ "${ON_BATTERY}" -eq 1 ]; then
			exit 0
	fi
fi

# check if we are already running (lockfile)
LOCKFILE="/var/lock/mlocate.daily.lock"
if [ -e "${LOCKFILE}" ]; then
	echo >&2 "Warning: \"${LOCKFILE}\" already present, not running updatedb."
	exit 1
fi
touch "${LOCKFILE}"
# trap the lockfile only if we really run the updatedb
trap "rm -f ${LOCKFILE}" EXIT

# source the user specified variables
if [ -f /etc/mlocate-cron.conf ]; then
	. /etc/mlocate-cron.conf
fi

# check the config file
NODEVS=""
if [ ! -f /etc/updatedb.conf ]; then
	NODEVS=$(awk '$1 == "nodev" && $2 != "rootfs" { print $2 }' /proc/filesystems)
fi

# alter the priority of the updatedb process
if [ -x /usr/bin/renice ]; then
	/usr/bin/renice +${NICE:-19} -p $$ > /dev/null 2>&1
fi
if [ -x /usr/bin/ionice ] && /usr/bin/ionice -c3 true 2>/dev/null; then
	/usr/bin/ionice -c${IONICE_CLASS:-2} -n${IONICE_PRIORITY:-7} -p $$ > /dev/null 2>&1
fi

# run the updatedb if possible
if [ -x /usr/bin/updatedb ]; then
	/usr/bin/updatedb -f "${NODEVS}"
else
	echo >&2 "Warning: \"/usr/bin/updatedb\" is not executable, unable to run updatedb."
	exit 0
fi