Ed's Computer Tips

Ed's Computer Blog

Intro

This blog documents random Linux computing tidbits I've found useful. Feel free to contact me if you find them useful or have a better way: ed@braaten-family.org.

Setup for Timed User Sessions

I did the following things to setup auto-logout/timed user-sessions for my son on our home computer running Linux (Ubuntu 11.04):

Edit file "/etc/security/time.conf" and added the following line:

login|gdm;*;toby;MoTuWeThFr1700-2000|MoTuWeThFr0800-1500
This limits the user "toby" to login only on weekdays between the specified times.
Add the following line after the "auth" statements in the "/etc/pam.d/login" and "/etc/pam.d/gdm" files:
account required pam_time.so
Add the following lines to root's crontab file (run "crontab -e" as the root user):
0 15 * * 1-5 /usr/bin/zenity --warning --text='Logging Toby off in 5 minutes!' --display=:0.0
5 15 * * 1-5 /usr/bin/killall -s KILL -u toby
0 20 * * 1-5 /usr/bin/zenity --warning --text='Logging Toby off in 5 minutes!' --display=:0.0
5 20 * * 1-5 /usr/bin/killall -s KILL -u toby

The zenity command is used to display a warning dialog in the Gnome session for the user "toby" five minutes before the killall command abruptly kills all running programs and the gnome session.
Add the following line to /etc/bash.bashrc:
xhost + >& /dev/null
This will allow the zenity command write to the user's session (see crontab entries).

Setup for Brother HL-2070N Printer

This is the printer setup for the Brother HL-2070N under CUPS on Ubuntu 11.04:

Download following two files from http://welcome.solutions.brother.com/:
- brhl2070nlpr-2.0.1-1.i386.deb
- cupswrapperHL2070N-2.0.1-2-i386.deb
Install these two files at a command prompt as root with:

dpkg -i brhl2070nlpr-2.0.1-1.i386.deb
dpkg -i cupswrapperHL2070N-2.0.1-2.i386.deb

Note that these are 32-bit packages. They can be installed on a 64-bit system (i86_64) by using the --force-architecture and --force-depends options to dpkg.

Connecting a Garmin GPS to a Linux Netbook

I purchased a Garmin Nuvi 2460LMT GPS device and was unable to complete the product registration on Garmin's web site using my Linux netbook. Garmin's web site requires the GPS device to be connected to the computer during the registration process by way of a custom browser plugin which communicates with the GPS. As of December 2011, Garmin's official plugin support was limited to computers running the proprietary Microsoft and Apple operating systems.

I used the following three commands at a command prompt to install a Linux compatible browser plugin from Andreas Diesner. This plugin allowed me to register my new Garmin Nuvi 2460LMT GPS device using a Linux netbook running the Linux version of Firefox.

sudo set-apt-repository ppa:andreas-diesner/garminplugin
sudo apt-get update
sudo apt-get install garminplugin

Removing Overlay Scrollbar

I found the overlay scrollbar feature difficult to use on my netbook. It is easily removed from Ubuntu with the following command (followed by a reboot):

sudo apt-get remove overlay-scrollbar liboverlay-scrollbar-0.1-0

Fixing BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key

This problem is fixed by rebuilding the apt lists directory in /var/lib/apt:

apt-get clean
cd /var/lib/apt
mv lists lists.old
mkdir -p lists/partial
apt-get clean
apt-get update