kidtimer

#!/bin/bash
# Restrict kids computer access to specific hours and total time.
# By: Michael Groves - grover66_at_gmail_dot_com

#variables
#LANG="en_US.UTF-8" #unremark to change preferred language.
basedir="/usr/local/kidtimer"
configdir="/etc/kidtimer"
Cdate=`/bin/date +%Y-%m-%d`
TUI=0
HOUR=`/bin/date +%H`
DOW=`/bin/date +%u`
WEEKEND="no"
[ "$DOW" == "6" ] && WEEKEND="yes"
[ "$DOW" == "7" ] && WEEKEND="yes"
[ ! -e $configdir/kid.list ] && touch $configdir/kid.list
[ ! -e $basedir/locale/$LANG ] && LANG="en_US.UTF-8"

#arguments
[ $# -eq 0 ] && TUI=1
[ $# -eq 1 ] && COMMAND=$1
[ $# -eq 2 ] && COMMAND=$1 && KID=$2
[ $# -eq 3 ] && COMMAND=$1 && KID=$2 && Time=$3

################# Subroutines ##################
################################################

#
# %%% not used yet
#
ttl_decr () {
   min=$1

   if [ $C -le 0 ]; then
      min=0
   else
      min=$((min - 1))
   fi
}

#
#  Decriment ttl (time to live) in mins and return current time left
#
set_ttl () {
   kid=$1
   min=$2

   #more time
   mtime=`date +%s`
   mfile=$(expr $mtime / 10000)
   if [ -e /tmp/$mfile ]; then
      /bin/rm -f /tmp/$mfile
      reset_time $kid
      return
   fi


   # Normal mode is to decriment a minute
   if [ -e $basedir/time/$kid.ttl ]; then
      min=`/bin/cat $basedir/time/$kid.ttl`
      if [ $min -le 0 ]; then
         min=0
      else
         min=$((min - 1))
      fi

      echo $min > $basedir/time/$kid.ttl

#first time for a user, create file, and set default ttl
   else
       get_ttl_time $kid > $basedir/time/$kid.ttl   
       min=`/bin/cat $basedir/time/$kid.ttl`
   fi

   return 0
}

get_info () {
echo "kidtimer info"
echo "---------------------------------------------"
/bin/date
echo "---"
echo "find /usr/local/kidtimer/ -print | sort"
/usr/bin/find /usr/local/kidtimer/ -print | /usr/bin/sort
echo "---"
echo "cat $configdir/kid.list"
/bin/cat $configdir/kid.list
echo "---"
echo "passwd -S -a"
/usr/bin/passwd -S -a
echo "---"
echo "cat /usr/local/kidtimer/schedule/*"
/bin/cat /usr/local/kidtimer/schedule/*
echo "---"
echo "cat /usr/local/kidtimer/time/*"
/bin/cat /usr/local/kidtimer/time/*
echo "---"
echo "cat /etc/cron.d/kidtimer"
/bin/cat /etc/cron.d/kidtimer
echo "---"
echo "apt-cache showpkg kidtimer"
/usr/bin/apt-cache showpkg kidtimer
echo "---"
echo "cat /etc/lsb-release"
/bin/cat /etc/lsb-release
echo "---"
echo "uname -a"
/bin/uname -a
echo "---"
echo "env"
/usr/bin/env
echo
}


go_check () {
for kid in `/bin/cat $configdir/kid.list | sort -u`; do

   # New day means we reset the ttl
   /usr/bin/stat -c %y $basedir/time/$kid.ttl | /bin/grep -q $Cdate
   if [ ! $? -eq 0 ]; then
      reset_time $kid
      return
   fi

    # This method ( /usr/bin/users ) to determine who is logged in is a kludge.  
    # It ignores locked screens (screensaver active) and switched user states.
    # change ttl for logged in user and return remaining time
    /usr/bin/users | /bin/grep -q $kid
    if [ $? -eq 0 ]; then

       set_ttl $kid $min

       # Are they allowed to use computer during this hour
       hourlyCheck $kid $allowed

       # check time, lock account, and start stutdown procedure, queue up jobs
       if [ $min -le 5 ] || [ $allowed -eq 0 ]; then
          go_logout $kid
       fi
    fi
done
}


get_ttl_time () {
        [ "$WEEKEND" == "no" ] && /bin/cat $basedir/schedule/$1 | /bin/grep ^MAX | /usr/bin/awk '{ print $2 }'
        [ "$WEEKEND" == "yes" ] && /bin/cat $basedir/schedule/$1 | /bin/grep ^MAX | /usr/bin/awk '{ print $3 }'
}


go_clean_jobs () {
K=$1
for I in `/usr/bin/atq | /usr/bin/awk '{ print $1 }' | /usr/bin/sort`; do
        /usr/bin/at -d $I
#        /usr/bin/at -c $I | /bin/grep -q "bash.$K"
#        [ $? -eq 0 ] && /usr/bin/at -d $I
done
[ -e /tmp/kidtimer.shutdown.$K ] && /bin/rm -rf /tmp/kidtimer.shutdown.$K
[ -e /tmp/kidtimer.send1.bash.$K ] && /bin/rm -rf /tmp/kidtimer.send1.bash.$K
[ -e /tmp/kidtimer.send2.bash.$K ] && /bin/rm -rf /tmp/kidtimer.send2.bash.$K
[ -e /tmp/kidtimer.send3.bash.$K ] && /bin/rm -rf /tmp/kidtimer.send3.bash.$K
[ -e /tmp/kidtimer.send4.bash.$K ] && /bin/rm -rf /tmp/kidtimer.send4.bash.$K
[ -e /tmp/kidtimer.send5.bash.$K ] && /bin/rm -rf /tmp/kidtimer.send5.bash.$K
[ -e /tmp/killall.bash.$K ] && /bin/rm -rf /tmp/killall.bash.$K
}


# From command line only.... check now handles this autmoatically... don't need
#   to run from cron
#
# runs once per day and resets ttl back for kid
# %%% what happens if machine is suspended and it missed its chance to run?
# 
go_daily () {
for I in `/bin/cat $configdir/kid.list | sort -u`; do

        /usr/bin/stat -c %y $basedir/time/$I.ttl | /bin/grep -q $Cdate
        #reset ttl for next day
        if [ ! $? -eq 0 ]; then
           reset_time $I
        fi
done
# %%% needs to be rethought
#go_hourly
}


#
# Determine if allowed to use computer during this schedule
#
hourlyCheck () {
kid=$1
allowed=$2
min=1 #non zero value is all we need

   if [ -e $basedir/schedule/$kid ]; then

      #grab mins left
      [ -e $basedir/time/$kid.ttl ] && min=`/bin/cat $basedir/time/$kid.ttl`
      #lock account if out of minutes

#%%% bug should return and not exit on 0
      if [ $min -le 0 ] ; then
        #/usr/bin/passwd $kid -l 
        allowed=0
        return 0
      fi

      # Disable/Enable depending on if allowed during time of day
      [ "$WEEKEND" == "no" ] && R=`/bin/grep ^$HOUR $basedir/schedule/$kid | /usr/bin/awk '{ print $2 }'`
      [ "$WEEKEND" == "yes" ] && R=`/bin/grep ^$HOUR $basedir/schedule/$kid | /usr/bin/awk '{ print $3 }'`
      if [ "$R" == "y" ]; then
         allowed=1   # allowed to use computer
      else
         allowed=0   # not allowed to use computer
      fi

   fi


   return 0
}

go_hourly () {
if [ -s $configdir/kid.list ]; then
        for I in `/bin/cat $configdir/kid.list | sort -u`; do
                if [ -e $basedir/schedule/$I ]; then
                        [ -e $basedir/time/$I.ttl ] && C=`/bin/cat $basedir/time/$I.ttl`
# %%% if ttl has gone negative, we lock password file and exit????
                        #[ $C -le 0 ] && /usr/bin/passwd $I -l && exit 0
                        [ $C -le 0 ] && exit 0
                        [ "$WEEKEND" == "no" ] && R=`/bin/grep ^$HOUR $basedir/schedule/$I | /usr/bin/awk '{ print $2 }'`
                        [ "$WEEKEND" == "yes" ] && R=`/bin/grep ^$HOUR $basedir/schedule/$I | /usr/bin/awk '{ print $3 }'`
                        if [ "$R" == "y" ]; then
                                /usr/bin/passwd $I -u
                        else
                                /usr/bin/passwd $I -l

# should gnome-screensaver-command -l

                                # This method ( /usr/bin/users ) to determine who is logged in is a kludge.  It ignores locked screens (screensaver active) and switched user states.
                                /usr/bin/users | /bin/grep -q $I
                                if [ $? -eq 0 ]; then
# %%% if this file exists, do no issue logout sequence
                            if [ ! -e /tmp/kidtimer.shutdown.$I ]; then
                                    go_logout $I
                    fi
                        fi
                        fi
                fi
        done
fi
}


go_logout () {
   kid=$1

   # only start this if they are logged in
   /usr/bin/users | /bin/grep -q $kid
    if [ $? -ne 0 ]; then
	return
    fi

   # schedule the shutdown if we haven't already
   if [ ! -e /tmp/kidtimer.shutdown.$kid ]; then
      go_send $kid 5
      go_send $kid 4
      go_send $kid 3
      go_send $kid 2
      go_send $kid 1
      go_killall $kid
      /usr/bin/touch /tmp/kidtimer.shutdown.$kid
   fi
}


go_send () {
K=$1
T=$2
LINE=$((7-$T))
TEXT=$((6-$T))
TMPFILE="/tmp/kidtimer.send$T.bash.$K"
/bin/rm -f $TMPFILE
touch $TMPFILE
chmod +x $TMPFILE

echo "#!/bin/bash" > $TMPFILE

# This method to determine the correct display doesn't work, at least on zorin.
# It only seems to detect a user who has an active shell running
#D=`/usr/bin/who | grep $K | grep -m1 "(:" | cut -d\( -f2 | sed s/\)// | sed s/://`

# So instead I'll just send the message to all the first 10 displays, and the ones owned by the correct user will show the message, the rest won't
if [ -e $basedir/locale/$LANG ]; then
    MSG="$K: `/bin/sed -n "$LINE"p /usr/local/kidtimer/locale/$LANG`"
else
    MSG="$K's computer time will end in $TEXT minutes."
fi

for (( D = 0 ; D < 10 ; D = D + 1 )); do
        echo "/bin/su $K -c 'DISPLAY=:$D /usr/bin/notify-send -i /usr/local/kidtimer/icons/kidtimer-$TEXT.png \
    \"ALERT\" \"$MSG\"'" >> $TMPFILE
done

echo "/bin/rm -f $TMPFILE" >> $TMPFILE
echo "/bin/bash $TMPFILE" | /usr/bin/at now + $T minutes
# Note you need the file /var/spool/cron/atjobs/.SEQ owned by daemon:daemon for at to work properly!!!
}


go_killall () {
K=$1
/bin/rm -f /tmp/killall.bash.$K
touch /tmp/killall.bash.$K
chmod +x /tmp/killall.bash.$K
#/usr/bin/passwd $K -l

echo "#!/bin/bash" > /tmp/killall.bash.$K
# Not sure if it is better or worse to do a normal kill first...
# Programs like Firefox will reopen all their previous tabs if it is killed with -KILL
# But other programs would probably do better if given a chance to save state/data and clean up after themselves eg open office???
#echo "/usr/bin/pkill -TERM -u $K" >> /tmp/killall.bash.$K
#echo "/bin/sleep 5" >> /tmp/killall.bash.$K
#
# should do gnome-screensaver-command -l and passwd -l here
# if user hibernates first and resumes, logic will continue up resumption
echo "/bin/rm -rf /tmp/kidtimer.shutdown.$K" >> /tmp/killall.bash.$K
echo "/bin/rm -f /tmp/killall.bash.$K" >> /tmp/killall.bash.$K
#echo "/usr/bin/pkill -KILL -u $K" >> /tmp/killall.bash.$K
echo "/usr/sbin/pm-hibernate" >> /tmp/killall.bash.$K
echo "/bin/bash /tmp/killall.bash.$K" | /usr/bin/at now + 6 minutes
}


go_echo_error () {
echo "`/bin/sed -n '12p' /usr/local/kidtimer/locale/$LANG`"
}


go_echo_done () {
echo "`/bin/sed -n '13p' /usr/local/kidtimer/locale/$LANG`"
}

reset_time () {
KID=$1

# make sure this kid is in the list to begin with
grep -q $KID $configdir/kid.list 
if [ $? -eq 0 ]; then
   get_ttl_time $KID > $basedir/time/$KID.ttl
   /usr/bin/passwd $KID -u
   go_clean_jobs $KID
   go_echo_done
fi
}

go_addtime () {
U=$KID
A=$Time
grep -q $U $configdir/kid.list
if [ $? -eq 0 ]; then
    if [ "$A" == "reset" ]; then
        get_ttl_time $U > $basedir/time/$U.ttl
            go_echo_done
            exit 0
    elif [ "$A" == "" ]; then
            go_echo_error
        #english: Syntax: addtime <user> <minutes|reset>
            echo "`/bin/sed -n '22p' /usr/local/kidtimer/locale/$LANG`"
            exit 1
    else
            C=`/bin/cat $basedir/time/$KID.ttl`
            C=$((C + Time))
            echo $C > $basedir/time/$KID.ttl
        get_time
    fi
    /usr/bin/passwd $KID -u
    go_clean_jobs $KID
else
    go_echo_error
    #english: User not setup.
    echo "`/bin/sed -n '19p' /usr/local/kidtimer/locale/$LANG`"
    exit 1
fi
}


get_time () {
if [ -e $basedir/time/$KID.ttl ]; then
    cat $basedir/time/$KID.ttl
else
    echo
    #english: User not setup.
    echo "`/bin/sed -n '19p' /usr/local/kidtimer/locale/$LANG`"
    echo
fi
}


go_tui () {
go_command_list
echo -n "Choose: "; read X
case "$X" in
1) go_setup_user
        ;;
2) go_modify_user
        ;;
3) go_remove_user
        ;;
4) go_list_users
        ;;
5) exit 0
        ;;
esac
go_tui
}


go_command_list () {
echo
echo "1) "`/bin/sed -n '7p' /usr/local/kidtimer/locale/$LANG`
echo "2) "`/bin/sed -n '8p' /usr/local/kidtimer/locale/$LANG`
echo "3) "`/bin/sed -n '9p' /usr/local/kidtimer/locale/$LANG`
echo "4) "`/bin/sed -n '10p' /usr/local/kidtimer/locale/$LANG`
echo "5) "`/bin/sed -n '11p' /usr/local/kidtimer/locale/$LANG`
echo
}


go_list_users () {
echo
#english: Users configured for kidtimer:
echo "`/bin/sed -n '14p' /usr/local/kidtimer/locale/$LANG`"
if [ -s $configdir/kid.list ]; then
        /bin/cat $configdir/kid.list
else
    #english: No configured users.
        echo "`/bin/sed -n '15p' /usr/local/kidtimer/locale/$LANG`"
    echo
fi
}

go_setup_user () {
echo
#english: Username:
echo -n "`/bin/sed -n '16p' /usr/local/kidtimer/locale/$LANG` "; read U
/usr/bin/id $U > /dev/null 2>&1
if [ $? -eq 0 ]; then
        /bin/cp $basedir/schedule/blank $basedir/schedule/$U
    get_ttl_time $U > $basedir/time/$U.ttl
        echo $U >> $configdir/kid.list
        go_echo_done
        echo
    #english: Modify limits now ?(y/n):
        echo -n "`/bin/sed -n '17p' /usr/local/kidtimer/locale/$LANG`"; read M
        if [ "$M" == "y" ]; then
                if [ -e /usr/bin/nano ]; then
                    /usr/bin/nano $basedir/schedule/$U
            get_ttl_time $U > $basedir/time/$U.ttl
                    go_echo_done
            else
                    /usr/bin/vi $basedir/schedule/$U
            get_ttl_time $U > $basedir/time/$U.ttl
                    go_echo_done
                fi
        fi
else
    go_echo_error
    #english: User does not exist. Please create user using the useradd command first.
        echo "`/bin/sed -n '18p' /usr/local/kidtimer/locale/$LANG`"
fi
}


go_modify_user () {
echo
#english: Username:
echo -n "`/bin/sed -n '16p' /usr/local/kidtimer/locale/$LANG` "; read U
grep -q ^$U $configdir/kid.list
if [ $? -eq 0 ]; then
        if [ -e /usr/bin/nano ]; then
                /usr/bin/nano $basedir/schedule/$U
                go_echo_done
        else
                /usr/bin/vi $basedir/schedule/$U
                go_echo_done
        fi
else
    go_echo_error
    #english: User not setup.
        echo "`/bin/sed -n '19p' /usr/local/kidtimer/locale/$LANG`"
    echo
fi
}


go_remove_user () {
echo
#english: Username:
echo -n "`/bin/sed -n '16p' /usr/local/kidtimer/locale/$LANG` "; read U
grep -q ^$U $configdir/kid.list
if [ $? -eq 0 ]; then
        /bin/grep -v ^$U $configdir/kid.list > /tmp/kidtimer.tmp
        /bin/cat /tmp/kidtimer.tmp > $configdir/kid.list
        go_echo_done
else
    go_echo_error
    #english: User not setup.
        echo "`/bin/sed -n '19p' /usr/local/kidtimer/locale/$LANG`"
    echo
fi
}


go_help () {
echo
echo "Commands:"
echo "--------------------------------------------------------------------------------"
echo "addtime <user> <minutes> ... Increases allowed time for the day."
echo "gettime <user> ... Prints remaining time for the day."
echo "reset <user> ... Reset time for the day."
echo "logout <user> ... Starts logout sequence for user."
echo "hourly ... Enables/disables user access based on the schedule."
echo "daily ... Resets time for the new day."
echo "update ... Updates kidtimer to the version."
echo "info ... Gather local configurations to troubleshoot issues."
echo "help ... This list."
echo "--------------------------------------------------------------------------------"
}

check_dependencies () {
#at
P1="";P2="";P3="";pstatus="0"
/usr/bin/dpkg -s at >/dev/null 2>/dev/null
if [ ! $? -eq 0 ]; then
    P1="at"
    pstatus=1
fi
#libnotify-bin
/usr/bin/dpkg -s libnotify-bin >/dev/null 2>/dev/null
if [ ! $? -eq 0 ]; then
        P2="libnotify-bin"
        pstatus=1
fi
#bsdutils
/usr/bin/dpkg -s bsdutils >/dev/null 2>/dev/null
if [ ! $? -eq 0 ]; then
        P3="bsdutils"
        pstatus=1
fi
if [ "$pstatus" == "1" ]; then
    echo
    #english: Error. Missing package dependencies.
    echo "`/bin/sed -n '20p' /usr/local/kidtimer/locale/$LANG`"
    #english: Please install using the following line;
    echo "`/bin/sed -n '21p' /usr/local/kidtimer/locale/$LANG`"
    echo "sudo apt-get install "$P1" "$P2" "$P3
    exit 1
fi
}

get_update () {
DEB_NAME='kidtimer.deb'
URL="https://github.com/SirYaro/kidtimer/raw/master/DEBS/${DEB_NAME}"
#'https://github.com/grover66/kidtimer/raw/master/DEBS/kidtimer_latest.deb'
if [ -e /usr/bin/wget ]; then
    /usr/bin/wget "$URL" -qO /tmp/${DEB_NAME}
    /usr/bin/dpkg -i /tmp/${DEB_NAME}
    /bin/rm -f /tmp/${DEB_NAME}
else
    echo
    echo "Error. Requires wget"
    echo "To install wget; sudo apt-get install wget"
fi
}


###################### Code ####################
################################################

if [ $TUI -eq 1 ]; then
    check_dependencies
    go_tui
fi

case "$COMMAND" in
addtime) go_addtime
        ;;
reset) reset_time $KID
        ;;
gettime) get_time
        ;;
logout) go_logout $KID
        ;;
hourly) go_hourly
        ;;
daily) go_daily
        ;;
update) get_update
        ;;
check) go_check
        ;;
info) get_info
        ;;
-h) go_help
        ;;
help) go_help
        ;;
esac
exit 0