Category Archives: Linux

Setting primary monitor (dual monitors) on Ubuntu 10.10

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I have my laptop connected to an external monitor, and I want the external monitor to be the primary display (i.e. with the menu bar displayed on it.) For some reason, there’s no GUI element to set this. I had to read a bunch of man pages, but when all else fails, trusty old xrandr to the rescue:

vijayp@ike:~$ xrandr --output HDMI1 --primary

In case you don’t know what your display is called, just run “xrandr” on its own. This is what my laptop says:

vijayp@ike:~$ xrandr
Screen 0: minimum 320 x 200, current 2880 x 1200, maximum 8192 x 8192
VGA1 disconnected (normal left inverted right x axis y axis)
LVDS1 connected 1280x800+0+0 (normal left inverted right x axis y axis) 261mm x 163mm
   1280x800       60.0*+
   1024x768       60.0
   800x600        60.3     56.2
   640x480        59.9
HDMI1 connected 1600x1200+1280+0 (normal left inverted right x axis y axis) 367mm x 275mm
   1600x1200      60.0*+
   1280x1024      75.0     60.0
   1152x864       75.0
   1024x768       75.1     60.0
   800x600        75.0     60.3
   640x480        75.0     60.0
   720x400        70.1
DP1 disconnected (normal left inverted right x axis y axis)

GPG error: http://ppa.launchpad.net

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When you get GPG errors when running apt-get update on your Ubuntu machine, you have to import the the appropriate keys.

W: GPG error: http://ppa.launchpad.net lucid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 4DEF31B9A9E345C0
W: GPG error: http://ppa.launchpad.net lucid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 0F678A01569113AE
W: GPG error: http://ppa.launchpad.net lucid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7889D725DA6DEEAA
W: GPG error: http://ppa.launchpad.net lucid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY FD58F8C9E8EF47D2
W: GPG error: http://ppa.launchpad.net lucid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY AF5ED91C56978EF9
W: GPG error: http://ppa.launchpad.net lucid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 464AD83D4631BBEA
W: GPG error: http://ppa.launchpad.net lucid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 6AF0E1940624A220
W: GPG error: http://ppa.launchpad.net lucid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 5A9A06AEF9CB8DB0
W: GPG error: http://ppa.launchpad.net lucid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 8CA7A6E8E4FA953A

Just run the following command :

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys KEYID

where KEYID is number shown in error msg

You can also import all the keys automatically. Tutorial here.

http://www.webupd8.org/2010/05/autom…l-missing.html

13 Of the Best Linux Tutorials and OpenCourseWare on the Web

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#1 IBM’s New to Linux

If you are brand new to Linux and have no idea what it is or what you can do with it, IBM’s Linux Introduction is worth checking out. This tutorial guides readers through everything they need to know to start working with Linux. The tutorial also provides links to hundreds of other articles, tutorials and training devices.

#2 Professor Norm Matloff’s Beginner’s Guide to Installing and Using Linux

Dr. Norm Matloff works for the Department of Computer Science at the University of California, Davis. He has created a fantastic guide to installing and using Linux. Designed specifically for beginners, the tutorial provides info on post-installation configuration, Linux usage, Linux applications software, dual boot issues, troubleshooting and much more.

#3 Linux Fundamentals Course

This Linux course, designed for new users, offers a brief history of Open Source Software and an introduction to Linux fundamentals. Basic commands are covered, as are other required topics for people who are just getting started with Linux. The Linux Fundamentals Course takes an estimated 18 hours to complete. Continue reading →

Delete all thumbs.db

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Windows creates in every folder with pictures a thumbs.db file.

Linux doesn’t need them, so here is a simple command to get rid of them.

sudo find /home/user -name Thumbs.db -exec rm {} \;

Remove empty directories

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To remove empty directories in a directory structure use the following command :

sudo find /begin/here -type d -empty -delete

Print on local in a Citrix Session using Ubuntu 10.10

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To add you local printer in your Citrix Session edit the following file

/usr/lib/ICACLIENT/config/wfclient.ini

Under the section WFClient add the following lines

DefaultPrinter = (here use the cups printer name for the printer you want)
DefaultPrinterDriver = Citrix PCL 4 Universal Driver

Apply the “200 Lines Kernel Patch That Does Wonders”

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  • The script has only been tested on Ubuntu (10.10 an 10.04)
  • Even though I’ve tested the script, it may not work for everybody so use it as is. There are no guarantees it will work and I take no responsibility if it doesn’t.
  • Always check the code of a script you run on your computer. You can download the script from HERE.
Now that you’ve read the “disclaimer”, you can go ahead and use the script.
Open a terminal and copy/paste the following commands:
cd
wget http://launchpadlibrarian.net/59511828/cgroup_patch
chmod +x cgroup_patch
sudo ./cgroup_patch

Now you can either restart your computer or simply run:

sudo /etc/rc.local
Credits and many thanks for the script: superpiwi @ Ubuntu Life.
Original post : WebUpd8

To Do List After installing Ubuntu 10.10 aka Maverick Meerkat

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I ran into this great post with todos after installing Ubuntu 10.10 today.
Here is the original

1 – Expand the Software Repository List

First of all, lets make Ubuntu “see” more packages. Go to the terminal and edit your sources.list with :

sudo gedit /etc/apt/sources.list

Here is the content of my sources.list which I think is quite complete to have all the necessary applications you could ever need. So delete the whole content of your sources list and replace it with the content of mine

Save it. Now import the necessary repositories keys to avoid “apt-get” crying about some missing keys, go to the terminal and type:

sudo apt-key adv –recv-keys –keyserver keyserver.ubuntu.com DCF9F87B6DFBCBAE F9A2F76A9D1A0061 A040830F7FAC5991 2EBC26B60C5A2783

Get your system up to date with :

sudo apt-get update && sudo apt-get dist-upgrade

Now all your programs will run on the last version.

2 – Anti-Virus

Windows equivalent : AVG AntiVirus, NAV, TrendMicro, F-Prot, Kaspersky, …

Ubuntu equivalent : ClamAV, Avast

ClamAV

sudo apt-get install clamav clamtk

Access it through System Tools → Virus Scanner .

Avast

wget http://files.avast.com/files/linux/avast4workstation_1.3.0-2_i386.deb && sudo dpkg -i avast4workstation_1.3.0-2_i386.deb

Access it through Accessories → avast! Antivirus .
Continue reading →

You have not chosen to trust “AddTrust External CA Root”, the issuer of the server’s security certificate.

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After installing the latest Citrix Client on my Ubuntu 10.10 laptop I wanted to log in a a Citrix Portal.

I got the following error.

You have not chosen to trust "AddTrust External CA Root", the issuer of the server's security certificate.

This solved my problem:

sudo cp /usr/share/ca-certificates/mozilla/*.* /usr/lib/ICAClient/keystore/cacerts/

Setting up the DCP-357c in Ubuntu 10.10

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In this earlier post I wrote down how I installed my Brother DCP-357c in Ubuntu 10.04

After upgrading to 10.10 the top edge of every page was cut off.
I ran into a post on loxdev.knc.nc where a the same problem was explained.

  1. Remove the brother-lpr-driver-extra & brother-cups-wrapper-extra from Synaptic Package Manager
  2. Download the drivers from the Brother site
  3. Then issue the following command
    4. # sudo mkdir -p /usr/share/cups/model
# sudo mkdir -p /var/spool/lpd/dcp353c
# sudo dpkg -i --force-all dcp353c*
  4. Download the brscan2 from the Brother site and then
    5. # sudo dpkg -i brscan*
  5. Then give the scanner the proper permissions
    6. # gksudo gedit /lib/udev/rules.d/40-libsane.rules
  6. Add this to the end of the hardware list of the file
    7. #Brother DCP-357C
ATTRS{idVendor}==”04f9″, ATTRS{idProduct}==”01e4″, ENV{libsane_matched}=”yes”
  7. And finally restart udev:
# sudo service udev restart