#!/bin/sh
### BEGIN INIT INFO
# Provides:          openalpr-daemon
# Required-Start:    $local_fs $network $remote_fs $syslog
# Required-Stop:     $local_fs $network $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: OpenALPR daemon for license plate recognition
# Description:       OpenALPR daemon detects license plate in the background
### END INIT INFO

# Author: Emmanuel Papin <manupap01@gmail.com>

unset USER

# PATH should only include /usr/* if it runs after the mountnfs.sh script
PATH=/sbin:/usr/sbin:/bin:/usr/bin
DESC="OpenALPR daemon"
NAME=openalpr-daemon
DAEMON=/usr/bin/alprd
PIDFILE=/var/run/alprd.pid
SCRIPTNAME=/etc/init.d/$NAME
DEFAULT=/etc/default/$NAME
USER=openalpr

# Exit if the package is not installed
[ -x "$DAEMON" ] || exit 0

# Read configuration variable file if it is present
[ -r $DEFAULT ] && . $DEFAULT

# Load the VERBOSE setting and other rcS variables
. /lib/init/vars.sh

# Define LSB log_* functions.
# Depend on lsb-base (>= 3.2-14) to ensure that this file is present
# and status_of_proc is working.
. /lib/lsb/init-functions

# Do not start the daemon if NO_START is enabled in DEFAULT
if [ "$START_DAEMON" != "yes" ] && [ "$1" != "stop" ]; then
	log_warning_msg "$NAME: Not starting $DESC."
	log_warning_msg "$NAME: Disabled in $DEFAULT."
	exit 0
fi

# Set the default log file
if [ -z $LOGFILE ]; then
	LOGFILE=/var/log/alpr.log
fi

# Run as `daemon' if USER is not specified or is `root'
if [ -z $USER ]; then
	USER=daemon
fi

# If no group is specified, use USER
if [ -z $GROUP ]; then
	GROUP=$USER
fi

DAEMON_ARGS="-l $LOGFILE $DAEMON_OPTS"

#
# Function that starts the daemon/service
#
do_start()
{
	# Return
	#   0 if daemon has been started
	#   1 if daemon was already running
	#   2 if daemon could not be started
	[ ! -f $LOGFILE ] && touch $LOGFILE && chown $USER:$GROUP $LOGFILE

	start-stop-daemon --start --quiet --pidfile $PIDFILE \
		--chuid $USER:$GROUP --exec $DAEMON --test > /dev/null \
		|| return 1
	start-stop-daemon --start --quiet --pidfile $PIDFILE \
		--chuid $USER:$GROUP --exec $DAEMON -- \
		$DAEMON_ARGS \
		|| return 2
}

#
# Function that stops the daemon/service
#
do_stop()
{
	# Return
	#   0 if daemon has been stopped
	#   1 if daemon was already stopped
	#   2 if daemon could not be stopped
	#   other if a failure occurred
	start-stop-daemon --stop --quiet --retry=TERM/30/KILL/5 --pidfile $PIDFILE --name $NAME
	RETVAL="$?"
	[ "$RETVAL" = 2 ] && return 2
	# Wait for children to finish too if this is a daemon that forks
	# and if the daemon is only ever run from this initscript.
	# If the above conditions are not satisfied then add some other code
	# that waits for the process to drop all resources that could be
	# needed by services started subsequently.  A last resort is to
	# sleep for some time.
	start-stop-daemon --stop --quiet --oknodo --retry=0/30/KILL/5 --exec $DAEMON
	[ "$?" = 2 ] && return 2
	# Many daemons don't delete their pidfiles when they exit.
	rm -f $PIDFILE
	return "$RETVAL"
}

#
# Function that sends a SIGHUP to the daemon/service
#
do_reload() {
	#
	# If the daemon can reload its configuration without
	# restarting (for example, when it is sent a SIGHUP),
	# then implement that here.
	#
	start-stop-daemon --stop --signal 1 --quiet --pidfile $PIDFILE --name $NAME
	return 0
}

case "$1" in
  start)
	[ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME"
	do_start
	case "$?" in
		0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
		2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
	esac
	;;
  stop)
	[ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME"
	do_stop
	case "$?" in
		0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
		2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
	esac
	;;
  status)
	status_of_proc "$DAEMON" "$NAME" && exit 0 || exit $?
	;;
  restart|force-reload)
	#
	# If the "reload" option is implemented then remove the
	# 'force-reload' alias
	#
	log_daemon_msg "Restarting $DESC" "$NAME"
	do_stop
	case "$?" in
	  0|1)
		do_start
		case "$?" in
			0) log_end_msg 0 ;;
			1) log_end_msg 1 ;; # Old process is still running
			*) log_end_msg 1 ;; # Failed to start
		esac
		;;
	  *)
		# Failed to stop
		log_end_msg 1
		;;
	esac
	;;
  *)
	echo "Usage: $SCRIPTNAME {start|stop|status|restart|force-reload}" >&2
	exit 3
	;;
esac

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