Ubuntu Tutorials

Not long ago the USB mouse that I’ve been using with my laptop finally died.  Granted it may have been due to me stubbing my toe on my backpack and crushing it during the middle of the night.  In any event, I’ve become pretty proficient in the use of keyboard shortcuts in Firefox at this point.  I thought I would share a few with you.

Navigation Shortcuts

Forward, backward, home, address bar and search bar can be done via keyboard shortcuts:

alt+Left Arrow : back

alt+Right Arrow : forward

alt+Home : Home

ctrl+L : address bar

F6 : address bar

ctrl+K : search bar

ctrl+K+Down Arrow : toggle search engine down

ctrl+K+Up Arrow : toggle search engine up

Tab Shortcuts

Opening, closing and navigating your tabs can be done via these shortcuts:

ctrl+t : new tab

ctrl+w : close tab

ctrl+Page Up : previous tab

ctrl+Page Down : next tab

ctrl+tab : next tab

alt+num (1, 2, 3, etc) : tab number

ctrl+shift+T : open recently closed tabs

ctrl+r : refresh tab content

ctrl+shift+r : force-refresh tab content

ctrl+u : view tab source

Are there any shortcuts that I’ve missed?  If you’ve got anything to share, comment.

Recently I blogged about the advanced permission management tool for nautilus, which could be switched on using the gconf-editor.  I noticed that one of the comments mentioned that neither of them had adequate support for ACLs.  This post will remedy that.

If you have no idea what ACLs are you might skip this post as I’m not going to go into detail explaining them. I simply want to outline how to add graphical support for ACLs with a tool called eiciel.

Installing eiciel

The eiciel package can be installed in Ubuntu by way of the standard repositories.  Either click the link below or run the command, and you’ll be on your way:

sudo aptitude install eiciel

This will install an extension to the native “Properties” of a file (find this via right-click, Properties) which will let you add and update ACLs.  note: You may not see this listed until you restart nautilus, which can be done using:

killall nautilus

Troubleshooting

If you find that this isn’t working for you you’ll need to ensure that your file system is mounted with ACL support.  This can be done one of the following ways:

sudo mount -o remount,acl /filesystem

You can also update your /etc/fstab to include “defaults,acl” for the filesystem(s) that you want to be supported and then remount.  Again, I’m assuming you know what ACLs are.  A definition for ACLs may be for a later post.

I just finished a phone conversation last night with the hosts of the Fresh Ubuntu podcast.  Someone suggested that I might make a good addition to the show, so you’ll get to hear me talk about Ubuntu related stuff (primarily LoCo work) for a half-hour or so on the next episode.

For those interested check out the episode link here: http://freshubuntu.org/podcast/146/

I like to keep on top of my machines health.  I like to do this without programs getting in my way, or dedicating desktop space to monitoring applications.  The way I’ve found to do this simply and effectively is with the System Monitor panel Applet.

Adding the System Monitor Applet

To add the system monitor applet to one of your panels (I prefer the top panel), simply right-click and select “Add to Panel”.  Scroll down until you see “System Monitor: A system load indicator”.  Select it and select Add.  You should now have a small black box on your panel which will monitor cpu activity.

I like to take this one step further and also monitor memory, network, load average, swap and disk activity.  This can be done by right-clicking on the new applet and selecting “Preferences”.  At the top of this preferences window you have the options of activating the resources you wish to monitor.  I check all of these boxes.

As you check each one you’ll get an additional box in your panel.  Each one monitors something different and in a different color (customizable).  You can now, at a glance, see the cpu load, network usage and all the rest without running any additional applications.

I find this to be a quick, efficient and out-of-the-way method of monitoring my machine.

A few of us were discussing minimal desktop environments the other day and I was reminded of the olden days when I used XFCE.  I really liked the clean interface which did not display any desktop icons by default.  Looking back on that I was reminded that it is an option available in Gnome as well, so here is how to do it.

Disable Desktop Icons In Gnome

A lot of Gnome configuration is done via the gconf-editor.  I’ll outline how to do this manually and graphically, including a command you can use to activate it from the shell.  Give it a try and let me know what you think.  Do you prefer icons or not?  They always seem like clutter to me.

The graphical method of stopping icons from displaying on your desktop is as follows:

Alt-F2 "gconf-editor"

Navigate to “apps > nautilus > preferences” and on the right-side look for “show_desktop”.  Toggling this will toggle, in real-time, the icons from being displayed on your Desktop

This setting can also be achieved by entering the following command at your shell:

gconftool-2 --set /apps/nautilus/preferences/show_desktop --type bool 0


and to revert these changes set the bool to 1:

gconftool-2 --set /apps/nautilus/preferences/show_desktop --type bool 1

Activating Additional Icons

A second, similar setting is to disable mounts from being displayed, or adding the “Computer”, “Home” or “Trash” icons to the desktop.  The graphical method of displaying the additional icons is as follows:

Alt-F2 "gconf-editor"

Navigate to “apps > nautilus > desktop” and select the boxes “computer_icon_visible”, “home_icon_visible”, “trash_icon_visible”.

Disabling the display of mount points (CDs, USB drives, etc) is done by deselecting the “volumes_visible” option.

Again, these can also be toggled by way of the following commands:

Activate Computer Icon

gconftool-2 --set /apps/nautilus/desktop/computer_icon_visible --type bool 1

Activate Home Folder Icon

gconftool-2 --set /apps/nautilus/desktop/home_icon_visible --type bool 1

Activate Trash Icon

gconftool-2 --set /apps/nautilus/desktop/trash_icon_visible --type bool 1

De-Activate Volumes

gconftool-2 --set /apps/nautilus/desktop/volumes_visible --type bool 0

If you use a Linux laptop and have not heard of PowerTop you really need to keep reading!  This is a fantastic tool for extending your battery life written and published by Intel.  I use it constantly on long flights and my battery lasts long enough for a cross-country flight.

Installing Powertop

PowerTop is available in the Ubuntu repositories so its a really easy installation:

sudo aptitude install powertop

Once you’ve got it installed start things up using:

sudo powertop

This application will scan your machine for 5 seconds and then tell you which hardware or application is causing the most drain on your machine.  The best part about it is that it’ll offer you suggestions along with shortcut keys to disable the feature or hardware in order to conserve power!

Some of the common things that powertop suggests disabling on my machine are bluetooth, wireless and add-on storage (cdrom, usb-devices, etc).  Disabling these few things can extend my battery up to an hour (depending on the software I’m running, of course).

I really suggest checking out powertop for any laptop user.  It should be part of your base installation setup.  What luck have you had with powertop?  How long can you extend your battery life?

I have been tunneling all of my web traffic over an encrypted SSH connection for some time now. Considering the fact that I travel a lot, I’m very regularly on untrusted, insecure networks. I prefer to secure those connections (web, IM, email, etc) by creating an encrypted SSH connection and pushing the traffic through it. Today I also found a method for also pushing DNS requests through the same tunnel. This ensures total privacy between yourself and the SSH dedicated server.

Step 1: Creating the Tunnel

Creating this private connection you’ll need a remote SSH server to connect to. Mine runs at home in my garage on an old Pentium III 500MHz box (yeah, the kind most people threw away long, long ago!). I connect to this tunnel using:

ssh -D 8080 -fN user@server

This creates a SOCKS compatible proxy, which is a requirement of the DNS forwarding. Other methods on the interwebs suggest using ssh -L or similar, which are not SOCKS compatible proxies.

Step 2: Forwarding DNS

If you’d like to also forward your DNS requests (ie; the site addresses you type into your browser), you’ll need to change a setting in Firefox. This can be done by accessing the address about:config, and entering this string into the configuration:

network.proxy.socks_remote_dns

Change this value to “true”.

Step 3: Using the Tunnel

The last step is to configure your browser to use these new settings. In Firefox 3 (I hope you’ve upgraded by now), you can activate/toggle these settings via:

Edit > Preferences > Advanced > Network > Settings

Select “Manual Proxy Configuration” and add localhost to the “SOCKS Host:” field, followed by port 8080 (assuming you’ve used the port in the example above).

This will then forward your web traffic through the SSH tunnel and DNS requests will also be forwarded.

You may want to check out the FoxyProxy plugin for a simpler way of toggling this on & off.

To deactivate the tunneling and use the local DNS again simply revert Step 3 back to “Direct Connection to the Internet”.

I blogged about openDNS last year, but recently I was reminded about how nice this service is.  OpenDNS can do a number of things for your network connection, either residential or commercial.  If you’d like to hear more about OpenDNS please visit the OpenDNS site.

Using OpenDNS on Ubuntu 8.04

There are two ways to activate OpenDNS on Ubuntu 8.04.  Graphically or via the CLI.  I’ll outline both.

Using the graphical method you’ll need to navigate to “System > Admin > Network”, and select the “DNS” tab.  You will need to unlock access to make changes by selecting the “Unlock” button.  Once it has been unlocked you can “Add” additional DNS Servers.  Add the following two addresses to your list:

208.67.222.222
208.67.220.220

To do the same via the command line simply add the following line to the end of the file /etc/dhcp3/dhclient.conf:

prepend domain-name-servers 208.67.222.222,208.67.220.220;

For information on configuring OpenDNS on your router or DNS Server see the getting started with OpenDNS page.

You can also verify that you’re using OpenDNS by visiting this URL:

http://welcome.opendns.com

update: I realize the formatting for this post is a bit screwed up.  If anyone has any tips on fixing it I’d appreciate it.  It looks fine in the editor view, but when I publish it everything gets screwy.

Today’s tip is a Gnome Desktop tweak that may be new to some of you.  Did you know you can activate a weather applet as part of your desktop clock?  You can also add locations around the globe, which can be a great way to keep track of day and night for all of your international buddies .

Activating the Weather Applet

To activate the Weather Applet right-click on the desktop clock in the top-right of your screen and select “Preferences”.

Select the “Locations” tab, and “Add” a location.

You’ll need to find your location around the globe within the list.

Once you’ve selected your location you can also change your weather preferences on the “Weather” tab.

Now you can enjoy weather at a glance, or quickly see the time around the globe for multiple locations!

It’s been a while since I’ve blogged about the Flock Browser, and after checking it out today I thought it was time for an update here at Ubuntu Tutorials.  For all of you that are addicted to all of the social networking sites (Digg, Twitter, Facebook, del.icio.us, Flickr, etc) you get an integrated-into-the-browser experience with the Flock Browser.  Follow the steps below and give ‘er a try:

Install Flock Browser v1.2 on Ubuntu 8.04

Unfortunately there are no .deb packages for the Flock Browser so you’ll have to install things manually.  Yes, this’ll require some commands at the terminal.  Yes, I’ll give you cut-and-paste commands.  No, the terminal won’t eat your cat.

1. Download Flock Browser v1.2 and select “Save File” to store it on your Desktop.
2. Open a terminal and run: sudo tar -C /opt -xzvf Desktop/flock-*.tar.gz
3. Create a link to the new browser within your PATH: sudo ln -s /opt/flock/flock /usr/bin/flock-browser
4. Dump the following into a new file: /usr/share/applications/flock.desktop

[Desktop Entry]
Encoding=UTF-8
Name=Flock
Comment=Flock Web Browser
Exec=flock-browser
Icon=/opt/flock/icons/mozicon128.png
StartupNotify=true
Terminal=false
Type=Application
Categories=Applications;Network

You should now have a new entry in your Applications menu called “Flock Web Browser” (your menu may need to refresh first).  You can also launch the browser from the terminal using the command:

flock-browser

Enjoy!  Anytime there is a Flock Browser update you should be able to safely repeat steps 1 and 2 and you’re set.