#!/bin/bash

if [ $# -ne 1 ]; then
echo “Usage $(basename $0) ”
exit
fi

if [[ -e "/var/lib/timekpr/$1.allow" ]]; then
rm “/var/lib/timekpr/$1.allow”
echo
echo “$1 has been disallowed to log in outside of normal logon hours”
echo
else
touch /var/lib/timekpr/$1.allow
echo
echo “$1 has been allowed to log in outside of normal logon hours”
echo
fi

#!/bin/bash

if [ $# -ne 2 ]; then
echo “Usage $(basename $0) ”
exit
fi

adj=$(($2*60))
now=$(cat /var/lib/timekpr/$1.time)
new=$(($now-$adj))
echo $new > /var/lib/timekpr/$1.time
limit=$(cat /var/lib/timekpr/$1)
left=$(($limit-$new))
echo
echo “$2 minute(s) added to ${1}s account.”
echo “$1 now has $(($left/60)) minute(s) left.”
echo

#!/bin/bash
###
# timekpr.sh - simple
# watches gnome sessions and logs them out once the user has exceeded a set, per day limit
# /var/lib/timekpr/$username.time hold a count of seconds user has had a gnome session
# /var/lib/timekpr/$username hold the daily allowed seconds for the user
#
# you may need to install notify-send with: $apt-get install libnotify-bin
#
# Copyright 2008 Chris Jackson
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# See .
#

default_limit=86400 # All day, new users is given this value
grace_period=60 # how much time do we give to let the user log out?
poll_time=20 # How often the script should check the timelogs
from=7 # When is the users allowed to log in
to=22 # When is the users no longer allowed to be loged in

#Ubuntu uses alternatives so we look for x-session-manager instead of gnome-session
SESSION_MANAGER=x-session-manager

function logOut() {
## get the display and xauthority used by out session manager
UDISPLAY=`grep -z DISPLAY \
/proc/$pid/environ | sed -e ’s/DISPLAY=//’`
XAUTHORITY=`grep -z XAUTHORITY \
/proc/$pid/environ | sed -e ’s/XAUTHORITY=//’`

# find DBUS session bus for this session
DBUS_SESSION_BUS_ADDRESS=`grep -z DBUS_SESSION_BUS_ADDRESS \
/proc/$pid/environ | sed -e ’s/DBUS_SESSION_BUS_ADDRESS=//’`
# use it - give a warning, then another one 1/2 way through grace_period
XAUTHORITY=”$XAUTHORITY” DISPLAY=”$UDISPLAY” DBUS_SESSION_BUS_ADDRESS=”$DBUS_SESSION_BUS_ADDRESS” \
notify-send –icon=gtk-dialog-warning –urgency=critical -t 10000 “$1″ “Your session is about to expire! You have $grace_period sec to save your work and logout.”
sleep $(($grace_period/2)) # FIXME: this gives other sessions a free grace_period added to their accounting

XAUTHORITY=”$XAUTHORITY” DISPLAY=”$UDISPLAY” DBUS_SESSION_BUS_ADDRESS=”$DBUS_SESSION_BUS_ADDRESS” \
notify-send –icon=gtk-dialog-warning –urgency=critical -t 10000 “$1″ “Your session is about to expire! You have $(($grace_period/2)) sec to save your work and logout.”
sleep $(($grace_period/2)) # FIXME: this gives other sessions a free grace_period added to their accounting

XAUTHORITY=”$XAUTHORITY” DISPLAY=”$UDISPLAY” DBUS_SESSION_BUS_ADDRESS=”$DBUS_SESSION_BUS_ADDRESS” \
notify-send –icon=gtk-dialog-warning –urgency=critical -t 10 “Shutting Down” “Shutting down session ($pid) now!”
# FIXME - should really check to see if user has logged out yet
sleep 10
kill -HUP $pid #this is a pretty bad way of killing a gnome-session, but we warned ‘em

## uncomment the following to brutally kill all of the users processes
sleep 10
pkill -u $username

## killing gnome-session should be more like:
#DISPLAY=”:0″ XAUTHORITY=”/tmp/.gdmEQ0V5T” SESSION_MANAGER=”local/wretched:/tmp/.ICE-unix/$pid” su -c ‘gnome-session-save –kill –silent’ $username
## but this can still leave processes to cleanup - plus it’s not easy to get SESSION_MANAGER

}

# get the usernames and PIDs of sessions

while(true); do
pidlists=$( ps –no-heading -fC $SESSION_MANAGER | awk ‘BEGIN{ FS=” ” } { print $1 “,” $2 }’ )
for pidlist in $pidlists; do

# split username and pid - FIXME - I bet this would be faster with bash arrays and substitution
username=$( echo $pidlist | awk ‘BEGIN{ FS=”,”} { print $1}’ )
pid=$( echo $pidlist | awk ‘BEGIN{ FS=”,”} { print $2}’ )

# If the user is not enabled, give him $default_limit
if [[ ! -e "/var/lib/timekpr/$username" ]]; then
echo $default_limit > /var/lib/timekpr/$username
fi

if [[ -e "/var/lib/timekpr/$username.time" && `( stat -c '%z' /var/lib/timekpr/$username.time | cut -c9,10 )` == `date +%d` ]]; then
# the time file exists and was last touched today, add $poll_time seconds to it
timekpr=$(( `cat /var/lib/timekpr/$username.time` + $poll_time ))
echo $timekpr > /var/lib/timekpr/$username.time
else # the time file is missing or was last touched yesterday
timekpr=$poll_time
echo $timekpr > /var/lib/timekpr/$username.time
fi

echo $username, $pid, $timekpr

# Is the user allowed to be loged in at this time?
# We take it for granted that if they are allowed to log in all day ($default_limit) then
# they can log in whenever they want, ie they are normal users
if [ $(cat /var/lib/timekpr/$username) -ne $default_limit ]; then
# Are we out of hours?
if ( [ $(date +%k) -lt $from ] || [ $(date +%k) -ge $to ] ); then
# Has the user been given extended log in hours?
if [[ -e "/var/lib/timekpr/$username.allow" ]]; then
# Was the extended log in hours given today?
if [[ $(stat -c '%z' /var/lib/timekpr/$username.allow | cut -c9,10) != $(date +%d) ]]; then
logOut “Only log in between $from and $to”
rm /var/lib/timekpr/$username.allow
fi
else
# User has not been given extended log in hours
logOut “Only log in between $from and $to”
fi
fi
fi

# Is the limit exeeded
if [[ $timekpr -ge `cat /var/lib/timekpr/$username` ]]
then
logOut “Daily time limit”
fi
done
# Wait a while before we check again
sleep $poll_time
done

I added the libnotify package and it worked out great. I also have a modified version of your script I’d like to send you. It limits the users login so that if they are logged out at 10pm (for instance), they can’t simply wait until midnight and start over. You can set the allowed time frame for usage to prevent sneaky kids.

I have one problem though. I added the line indicated above that should start the script upon reboot but it doesn’t restart. My youngest has already learned all she needs to do is reboot the computer and she has unlimited time (unless I login and launch the script).

I added a line to /etc/rc.local

/usr/local/bin/timekpr &

This isn’t working, can you help me with this?

The file was made and I set it to 300 for testing. I watched it tick away, and then several more minutes went bye. Then suddenly it logged me off. It NEVER displayed a warning. I’m fine with that.

PROBLEM: Once it logged me out of my test user, it let me log right back in again. I waiting to see if this will kick me off again.

There needs to be a way to prevent the person from logging back in and stealing yet a few more minutes.

test@MSI-K8N-NEO4-PLAT-SLI:~$ sudo echo 300 > /var/lib/timekpr/test
bash: /var/lib/timekpr/test: Permission denied
test@MSI-K8N-NEO4-PLAT-SLI:~$

I logged in as the primary original and as the newly created test account and get the same error each time.

Help me make this work please.

Ebben a leírásban egy olyan, Ubuntu alatt használható módszert mutatok be, amivel a rendszer felhasználóinak számítógép használati idejét lehet korlátozni. Amennyiben az el?re beállított id? lejár, a felhasználó kijelentkezik, és …

$ sh /usr/local/bin/timekpr.sh

will over ride the #! line in the script and use the wrong shell. To fix it, either run as:

$ bash /usr/local/bin/timekpr.sh

or set it executable ( “$ chmod 755 /usr/local/bin/timekpr.sh” ) and execute it directly.

I’ll have to look at making it “dash” compatible at some point.

/usr/local/bin/timekpr.sh: 94: [[: not found
/usr/local/bin/timekpr.sh: 94: [[: not found
robson, 6202, 20

The value stored in /var/lib/timekpr/robson.time is 20, never more than it.

Could you help me?

A system tray applet that displays the remaining time and can launch the time editor (after a gksudo login) sounds like a great idea!

Translations is also a great idea - I am afraid I’m personally limited to English, so any help is appreciated!

But I’ll also try to upgrade it, here is a list of functionalities I believe we can improve:

Must Have
1) Different limitations per day of the week
2) Limit not only by seconds in use, also by specific times of the day, it would be like the user connects but has only 30 seconds to logout (or will be forced logout) if he is not inside a allowed window.
3) Hability to extend the allowed time for the current day if an administrator types in a password and how many time to extend (this would attend your need to give extra time as reward).

Good to Have
4) A graphical interface to administer these options
5) Prevent the user to manually change his control file to “obtain” extra time.
6) A better logout method, something that pushes a logout allowing to save data
7) Support for different languages, best if it is done by plug ins (will allow anyone to create a plug in)
Create a control window for the user, so he can check the remaining time at any time and giving him some options, could be the ability to use extra credit (off course reducing the credit from a pool)
9) Create a .deb package

I personally don’t have much available time, but I also need to ensure proper usage for my teenagers (that is thought) so I will try, first thing first, I will translate the script to Brazilian-Portuguese as I am from Brazil and post it for anyone else to use.

My script is in active use at our house and has been effective in limiting my teens computer time - that being said, I really need to add a GUI so my wife can control their time allotments and I would like to add some kind of a reward system where Mom can give them extra time to use when they want when they have earned it.