Setting primary monitor (dual monitors) on Ubuntu 10.10

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

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

#1 IBM’s New to Linux

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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

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

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

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