Enhanced transmission script for your DNS-323

I miss the ability to auto-stop/shutdown the bittorrent client after all downloads have completed hence I decided to port the old mldonkey script over. Here is a quick summary on what it does.

• Improved the robustness of the startup, shutdown and restart sequence.
• Added function to auto-stop transmission when there are no more active downloads.
• Added function to auto-shutdown the box when there are no more active downloads.
• Added function to configure the behavior when there are no more active downloads. Valid arguments are:
• set_stop_when_done - stops transmission when there are no more active downloads;
• set_off_when_done - shutdowns the box when there are no more active downloads;
• set_donothing_when_done - let transmission continue to run when there are no active downloads (i.e. seeding);
• Use the function softstop_status to check what is the current configuration option.

The default behavior is set_stop_when_done. Command syntax is . /ffp/start/transmission.sh [cmd]. Here is the script below.

#!/ffp/bin/sh

###################################################################
# author: Sidney Chong (bfg100k[at]gmail.com)                     #
# version: 0.1                                                    #
# date: 15/05/2008                                                #
#                                                                 #
# Version History                                                 #
# ---------------                                                 #
# v0.1 - expanded original startup script to be more robust and   #
#        include auto-stop or auto-shutdown the box when          #
#        downloads are completed.                                 #
#                                                                 #
###################################################################

if [ -z ${TRANSMISSION_HOME} ]; then
  #setup the ENV variables if not found
  #this can happen when running from crontab
  echo "Environment variables not found, including default fun_plug profile."
  . /ffp/etc/profile
fi

TMP_CRONTAB="/ffp/log/crontab.tmp"

name="transmission-daemon"
command="/ffp/bin/transmission-daemon"
user=nobody

transmission_start()
{
  #check if daemon is already running. if yes, do nothing
  if transmission_status  grep -q "is running"; then
    echo "INFO: ${name} already running! Nothing to do."
    return
  fi

  if [ ! -d $TRANSMISSION_HOME ]; then
    su $user -c "mkdir $TRANSMISSION_HOME"
  fi
  echo "Starting ${name}..."
  su $user -c "$command -f -v 2 1>$TRANSMISSION_HOME/$name.log 2>&1 &"
  sleep 1
  if [ -S $TRANSMISSION_HOME/daemon/socket ]; then
    chmod 0777 $TRANSMISSION_HOME/daemon/socket
  else
    echo "Could not find Transmission socket"
    return
  fi

  #this step configures what to do if there are no more active downloads
  #default (stop_when_done) is to stop transmission.
  #change to off_when_done if you want to shutdown the box
  #change to donothing_when_done if you want to let it run (e.g. for seeding)
  _transmission_setup_softstop stop_when_done

  echo "Transmission startup sequence completed. Check ${TRANSMISSION_HOME}/${name}.log for more details."
}

transmission_stop()
{
  if transmission_status  grep -q "is running"; then
    echo -n "Stopping ${name}... "
  if [ -x /ffp/bin/transmission-remote ]; then
   /ffp/bin/transmission-remote -q
  else
   /bin/kill -9 $(pidof $command)
  fi
    echo "done."
  else
    echo "INFO: ${name} not running! Nothing to stop."
  fi
  _transmission_setup_softstop
  echo "${name} stop sequence completed."
}

transmission_status()
{
 _pids=$(pidof $name)
 if test -n "$_pids"; then
  echo "$name is running"
 else
  echo "$name not running"
 fi
}

transmission_softstop_status()
{
  if crontab -l  grep -q 'softstop_off';
  then
    echo "DNS-323 will shutdown when there are no active downloads."
  else
    if crontab -l  grep -q 'softstop';
    then
      echo "${name} will stop when there are no active downloads."
    else
      echo "softstop has not been configured."
    fi
  fi
}

transmission_restart()
{
  transmission_stop
  echo "Waiting for old instance to shutdown before starting new daemon..."
  while transmission_status  grep -q "is running"
  do
    sleep 5
  done
  transmission_start
}

# this routine checks to see if transmission is still alive
# and if there are any downloads active.
# if no downloads are active, it attempts to stop transmission.
# if "off_when_done" option is specified, it will attempt to
# shutdown the DNS-323 as well.
_transmission_softstop()
{
  echo -n "`date`: Checking downloads... "
  if /ffp/bin/transmission-remote -l  grep -q 'downloading';
  then
    echo "downloads are still active!"
  else
    echo "no active downloads found!"
    transmission_stop
    if [ "${1}" = "off_when_done" ]; then
      echo "attempting to shutdown the DNS-323 now. Bye Bye!"
      touch /tmp/shutdown
    fi
  fi
}

# this routine sets up softstop as a cron job that runs every half hour
# to ADD the cron job, pass "stop_when_done" into the routine,
# to ADD the cron job with shutdown option, pass "off_when_done",
# any other values (or no value) means REMOVE by default
_transmission_setup_softstop()
{
  echo "Setting up softstop on crontab... "
  crontab -l > ${TMP_CRONTAB}
  sed -i -e '/transmission.sh softstop/d' ${TMP_CRONTAB}
  TMP_NAME=""
  case "$1" in
    stop_when_done)
      TMP_NAME="softstop"
      echo "INFO: This job will stop $name when all downloads are completed."
    ;;
    off_when_done)
      TMP_NAME="softstop_off"
      echo "INFO: This job will attempt to shutdown the DNS-323 when all downloads are completed."
    ;;
    *donothing_when_done)
      echo -n "Removing job from crontab... "
    ;;
  esac
  if [ "${TMP_NAME}" != "" ]; then
    # sanity check - do not allow adding any job if transmission is not already running
    if transmission_status  grep -q "is running"; then
      echo -n "Adding cron job to run every half hour... "
      echo -e "0,30 * * * * /ffp/start/transmission.sh ${TMP_NAME} >> /ffp/log/${name}.cron.log 2>&1" >> ${TMP_CRONTAB}
      sed -i -e '/^\s*$/d' ${TMP_CRONTAB}
    else
      echo "ERROR: ${name} is not running. NOT adding job to crontab."
    fi
  fi
  crontab ${TMP_CRONTAB}
  rm ${TMP_CRONTAB}
  echo "done."
}


case "$1" in
  stop)
    transmission_stop
    ;;
  softstop)
    _transmission_softstop
    ;;
  softstop_off)
    _transmission_softstop off_when_done
    ;;
  set_off_when_done)
    _transmission_setup_softstop off_when_done
    ;;
  set_stop_when_done)
    _transmission_setup_softstop stop_when_done
    ;;
  set_donothing_when_done)
    _transmission_setup_softstop donothing_when_done
    ;;
  softstop_status)
    transmission_softstop_status
    ;;
  restart)
    transmission_restart
    ;;
  status)
    transmission_status
    ;;
  start'')
    transmission_start
    ;;
  *)
    echo "Usage: $0 startstoprestartstatusset_off_when_doneset_stop_when_doneset_donothing_when_donesoftstop_status"
    ;;
esac