#! /bin/bash

set -e

[ -x /usr/bin/updatedb.mlocate ] || exit 0

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
	echo >&2 "System on battery power, not running updatedb."
	exit 1
    fi
fi

##

LOCKFILE="/var/lib/mlocate/daily.lock"

trap "rm -f $LOCKFILE" EXIT

if [ -e "$LOCKFILE" ]; then
    echo >&2 "Warning: $LOCKFILE present, not running updatedb."
    exit 1
else
    touch "$LOCKFILE"
fi

##

# See ionice(1)
if [ -x /usr/bin/ionice ] &&
    /usr/bin/ionice -c3 true 2>/dev/null; then
    IONICE="/usr/bin/ionice -c3"
fi

# See nice

if [ -x /usr/bin/nice ] &&
    /usr/bin/nice -n 19 true 2>/dev/null; then
    NICE="/usr/bin/nice -n 19"
fi


$NICE $IONICE /usr/bin/updatedb.mlocate