run file for no-restarting daemon process

run

#!/bin/sh
#
# run file for no-restarting daemon process
# http://d.hatena.ne.jp/hirose31/20130529/1369831078
#
exec 2>&1
runfile=$(readlink -f $0)
rundir=${runfile%/*}
daemon=/home/hirose31/hoged
opts=''

pidfile="$rundir/pid"

if [ -e $pidfile ]; then
  old_pid=$(cat $pidfile)
  # remain daemon process when run process receive SIGKILL
  # so try to kill old daemon process but THIS IS VERY DENGEROUS!!
  # because not daemon process may be killed...
  echo "$old_pid still exists"
  case $old_pid in
    [1-9][0-9]*)
      echo "kill $old_pid"
      kill -KILL $old_pid
      ;;
  esac
  echo "do svc -d me"
  svc -d $rundir
  exit
fi

pid=
# kill background daemon process if run process receive a signal
trap 'kill -TERM $pid' TERM
trap 'kill -TERM $pid' HUP
trap 'kill -TERM $pid' INT

echo "run in background: $daemon $opts"
setuidgid hirose31 \
  env - PATH="/usr/local/bin:$PATH" \
  envdir ./env \
  $daemon $opts &

pid=$!
echo $pid > $pidfile
echo "wait for exiting $pid"
wait $pid
echo "$pid exited"