rtorrent start/stop/restart script

#!/bin/bash
# rTorrent Stop/Start/Restart
PATH=/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/bin:/sbin
FILE="$HOME/rtorrent/.session/rtorrent.lock"
SERVICE='rtorrent'
RTPID=$(pidof $SERVICE)
# Sets default status can be askkill, autokill, or donotkill
KILLSTATUS='askkill'
KILLSIGNAL='-15'
RTLOG="/dev/null"
loglines=500
useerr=0
LOGFLAG=0

# write log file
log_header() {
RTLOG="$HOME/rt.log"
echo >> $RTLOG
date >> $RTLOG
echo "$0 $@" >> $RTLOG
if [ $(cat "$RTLOG" | wc -l) -gt $loglines ]
  then
    tail -$loglines  "$RTLOG" > $HOME/rt.temp
    cat $HOME/rt.temp > $RTLOG
    rm -f $HOME/rt.temp
fi
}

# function to check if service is running
service_running(){
if pidof $SERVICE > /dev/null
  then
    return 0
  else
    return 1
fi
}

# function to ask user for y/n response
ask_user(){
if [ -t 1 ]
  then
    while true
      do
      read -p "Unable to close $SERVICE, close using kill -9? " answer
      case $answer in [Yy]* ) return 0 ;;
                      [Nn]* ) return 1 ;;
                          * ) echo "Enter y or n";;
      esac
    done
  else
    echo "Running in background -a auto response is n" >> $RTLOG
    return 1
fi
}

# function that starts service
start_service(){
  local seconds=0
  if [ $SERVICE = "rtorrent" ]
    then
      if [ -a $FILE ]
        then
          echo "removing $FILE" | tee -a "$RTLOG"
          rm -f $FILE
        else
          echo "No session lock file" | tee -a "$RTLOG"
      fi
  fi

  echo -n "Starting $SERVICE"
  screen -d -m -S $SERVICE $SERVICE

  while ! (service_running)
    do
      seconds=$(( $seconds + 1 ))
      echo -n "."
      sleep 1
      if [ $seconds = 10 ]
        then
          echo
          return 1
      fi
  done

  echo
  return 0
}

# function that stops service
stop_service(){
 local seconds=0
 echo -n "$SERVICE shutting down using kill $1"
 kill $1 $RTPID

 while ( service_running )
   do
     seconds=$(( $seconds + 1 ))
     echo -n " ."
     sleep 1
     if [ $seconds = 20 ]
       then
         echo
         return 1
     fi
   done

   echo
   return 0
}

# reports any usage error
usage_error() {
echo "usage: [-h] [-a|-k|-d] [-l] [start | stop | restart]" | tee -a "$RTLOG"
if [ $1 = 1 ]
  then
    echo "only one of the options -a -k -d allowed" | tee -a "$RTLOG"
fi

if [ $1 = 2 ]
  then
    echo "incorrect option used" | tee -a "$RTLOG"
fi

if [ $1 = 3 ]
  then
    echo "incorrect argument used" | tee -a "$RTLOG"
fi

if [ $1 = 4 ]
  then
    echo "too many arguments, only 1 argument allowed" | tee -a "$RTLOG"
fi


exit 1
}

# prints usage help to screen
usage_help() {
echo "usage: [-h] [-a|-k|-d] [-l] [start | stop | restart]"
echo "options:"
echo "  -h usage help display"
echo "  -l send results to log file"
echo "  -a if unable to close service ask user whether to use kill -9"
echo "  -k if unable to close service use kill -9"
echo "  -d if unable to close service do not use kill -9"
echo "arguments:"
echo "  start starts the service"
echo "  stop stops the service"
echo "  restart first stops and then starts the service"

exit 0
}


# Check for options
while getopts ":hlkad" optname
  do
    case $optname in
      "k" )[[ -n $OPTFLAG ]]  && useerr=1 || KILLSTATUS='autokill' && OPTFLAG=1 ;;
      "a" )[[ -n $OPTFLAG ]]  && useerr=1 || KILLSTATUS='askkill' && OPTFLAG=1 ;;
      "d" )[[ -n $OPTFLAG ]]  && useerr=1 || KILLSTATUS='donotkill' && OPTFLAG=1 ;;
      "l" ) LOGFLAG=1 ;;
      "h" ) usage_help ;;
        * ) useerr=2 ;;
    esac
  done

if [ $LOGFLAG = 1 ]
  then
    log_header "$@"
fi

if [ $useerr -gt 0 ]
  then
    usage_error $useerr
fi

shift $(( $OPTIND - 1 ))

# Check correct arguments used
if [ $# = 1 ]
  then
    if ! [[ $1 = "stop" || $1 = "start" || $1 = "restart"  ]]
      then
        useerr=3
        usage_error $useerr
    fi
fi

# Check if there is more than 1 argument
if [ $# -gt 1 ]
  then
    useerr=4
    usage_error $useerr
fi

# Check if service is running
if [ $# = 0 ]
  then
    if ( service_running )
      then
        echo "$SERVICE is running"
      else
        echo "$SERVICE is NOT running"
    fi
fi

# Stop Service
if [[ $1 = "stop" || $1 = "restart" ]]
  then
    if ! ( service_running )
      then
        echo "$SERVICE was not running"
      else
        if ! ( stop_service $KILLSIGNAL )
          then
            case $KILLSTATUS in
              "autokill" )
                KILLSIGNAL='-9'
                stop_service $KILLSIGNAL ;;
              "askkill" )
                if ( ask_user )
                  then
                    KILLSIGNAL='-9'
                    stop_service $KILLSIGNAL
                fi ;;
            esac
        fi

        if ( service_running )
          then
            echo "WARNING unable to close $SERVICE using $KILLSIGNAL" | tee -a "$RTLOG"
            exit 1
          else
            echo "$SERVICE has been closed using kill $KILLSIGNAL" | tee -a "$RTLOG"
        fi
    fi
fi

# Start Service
if [[ $1 = "start" || $1 = "restart" ]]
  then
    if ( service_running )
      then
        echo "$SERVICE was already running"
      else
        if ( start_service )
          then
            echo "$SERVICE has been started" | tee -a "$RTLOG"
          else
            echo "WARNING: Unable to start $SERVICE" | tee -a "$RTLOG"
        fi
    fi
fi

echo "There were no problems encountered" >> "$RTLOG"