Init for rtorrent

#!/bin/bash

### BEGIN INIT INFO
# Provides:          rtorrent
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Should-Start:      $portmap
# Should-Stop:       $portmap
# X-Start-Before:    nis
# X-Stop-After:      nis
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# X-Interactive:     false
# Short-Description: Initscript for rtorrent
# Description:       This file should be used to start|stop rtorrent
### END INIT INFO


##Start Configuration##
PATH=/usr/bin:/usr/local/bin:/usr/local/sbin:/sbin:/bin:/usr/sbin
DESC="rtorrent"
NAME="rtorrent"
DAEMON=$NAME
SCRIPTNAME=$0

# file to log to (makes for easier debugging if something goes wrong)
logfile="/var/log/rtorrentInit.log"

# Users list
users="alex liza"

###END CONFIGURATION###


checkcnfg() {
    exists=0
    for i in `echo "$PATH" | tr ':' '\n'` ; do
        if [ -f $i/$NAME ] ; then
            exists=1
            break
        fi
    done
    if [ $exists -eq 0 ] ; then
        echo "cannot find rtorrent binary in PATH $PATH" | tee -a "$logfile" >&2
        exit 3
    fi
    if ! [ -r "${config}" ] ; then
        echo "cannot find readable config ${config}. check that it is there and permissions are appropriate" | tee -a "$logfile" >&2
        exit 3
    fi
    session=`getsession "$config"`
    if ! [ -d "${session}" ] ; then
        echo "cannot find readable session directory ${session} from config ${config}. check permissions" | tee -a "$logfile" >&2
        exit 3
    fi
}


d_start() {
    for user in $users; do
        # the full path to the filename where you store your rtorrent configuration
        config="`su -c 'echo $HOME' $user`/.rtorrent.rc"
        # set of options to run with
        options=""
        # default directory for screen, needs to be an absolute path
        base="`su -c 'echo $HOME' $user`"
        # name of screen session
        srnname="rtorrent"

        echo "Start for $user; Config='$config'; Base='$base'" | tee -a "$logfile"

        checkcnfg

        [ -d "${base}" ] && cd "${base}"
        stty stop undef && stty start undef
        su -c "screen -ls | grep -sq "\.${srnname}[[:space:]]" " ${user} || su -c "screen -dm -S ${srnname} 2>&1 1>/dev/null" ${user} | tee -a "$logfile" >&2
        # this works for the screen command, but starting rtorrent below adopts screen session gid
        # even if it is not the screen session we started (e.g. running under an undesirable gid
        #su -c "screen -ls | grep -sq "\.${srnname}[[:space:]]" " ${user} || su -c "sg \"$group\" -c \"screen -fn -dm -S ${srnname} 2>&1 1>/dev/null\"" ${user} | tee -a "$logfile" >&2
        su -c "screen -S "${srnname}" -X screen rtorrent ${options} 2>&1 1>/dev/null" ${user} | tee -a "$logfile" >&2
    done
}


d_stop() {
    for user in $users; do
        # the full path to the filename where you store your rtorrent configuration
        config="`su -c 'echo $HOME' $user`/.rtorrent.rc"
        # set of options to run with
        options=""
        # default directory for screen, needs to be an absolute path
        base="`su -c 'echo $HOME' $user`"
        # name of screen session
        srnname="rtorrent"

        checkcnfg

        session=`getsession "$config"`
        if ! [ -s ${session}/rtorrent.lock ] ; then
            return
        fi
        pid=`cat ${session}/rtorrent.lock | awk -F: '{print($2)}' | sed "s/[^0-9]//g"`
        if ps -A | grep -sq ${pid}.*rtorrent ; then # make sure the pid doesn't belong to another process
            kill -s INT ${pid}
        fi
    done
}


getsession() {
    session=`cat "$1" | grep "^[[:space:]]*session[[:space:]]*=" | sed "s/^[[:space:]]*session[[:space:]]*=[[:space:]]*//" `
    echo $session
}


case "$1" in
  start)
    echo -n "Starting $DESC: $NAME"
    d_start
    echo "."
    ;;
  stop)
    echo -n "Stopping $DESC: $NAME"
    d_stop
    echo "."
    ;;
  restart|force-reload)
    echo -n "Restarting $DESC: $NAME"
    d_stop
    sleep 1
    d_start
    echo "."
    ;;
  *)
    echo "Usage: $SCRIPTNAME {start|stop|restart|force-reload}" >&2
    exit 1
    ;;
esac

exit 0