#!/bin/sh

#
# autostart.  Start a process and monitor it by sending signal 0 to the
#  the pid listed in pidfile.  If it's not responding, restart
#
# to manually restart the process without restarting autostart and
# avoiding race conditions:
#
#  grab the pid from /var/run/xxx.pid
#  remove /var/run/xxx.pid
#  kill/restart
#
# maf - May 1999

while getopts "c:m:p:r:R:s:" option; do

  case $option in

  c) # command
    COMMAND="${OPTARG}";;

  m) # monitor existing proc, don't startup
    MON="${OPTARG}";;

  p) # pidfile
    PIDFILE="${OPTARG}";;

  r) # restart if file is newer than pidfile
    RESTART="${OPTARG}";;

  R) # restart sleeptime
    RESTART_SLEEPTIME="${OPTARG}";;

  s) # sleep time
    SLEEPTIME="${OPTARG}";;

  *) #
    exit 1;;

  esac
done

if [ "X${SLEEPTIME}" = X ]; then
  SLEEPTIME=60
fi

if [ "X${RESTART_SLEEPTIME}" = X ]; then
  RESTART_SLEEPTIME=60
fi

if [ "X${PIDFILE}" = X ]; then
  echo Must specify pidfile with -p 1>&2
  exit 1;
fi

if [ "X${COMMAND}" = X ]; then
  echo Must specify command with -c 1>&2
  exit 1;
fi

if [ "X${MON}" = "X" ]; then
  logger -p daemon.notice "$COMMAND started"
  $COMMAND &
  sleep $RESTART_SLEEPTIME
fi

while :; do

  sleep $SLEEPTIME

  while [ ! -f $PIDFILE ]; do
    logger -p daemon.notice "$PIDFILE missing"
    sleep 5
  done

  # auto start if config file is newer?
  if [ "X${RESTART}" != "X" ]; then
    if [ $RESTART -nt $PIDFILE ]; then
      logger -p daemon.notice "terminating $COMMAND"
      kill -9 `cat $PIDFILE` 2>/dev/null
    fi
  fi

  kill -0 `cat $PIDFILE` 2>/dev/null && continue

  logger -p daemon.notice "restarting $COMMAND"

  $COMMAND &
  # give some extra startup time
  sleep $RESTART_SLEEPTIME

done