To try GNOME Shell Extensions, you’ll need to be running GNOME 3.2. Ubuntu 11.10 only has GNOME 3.0, but the GNOME3 Team PPA provides packages to update it. I added this PPA on my netbook to update my existing GNOME Shell installation in Ubuntu 11.10.

Extensions are installed using a plugin, included with GNOME, that currently only works with Firefox. When it’s working, an extension’s page has a large switch to enable and disable the extension. Flip the switch, select Install in the confirmation dialog, and the extension almost immediately activates. Disabling an extension is just as easy. Here’s the Applications Menu extension in action:

I’d like to see an extension that maximizes screen space on my netbook by hiding the title bar of maximized windows like Unity does.

Could GNOME Shell extensions become a killer feature for GNOME 3?

• qgit, as the name suggests, uses the QT GUI toolkit. qgit is a gitk-style interface for viewing revisions. Before you can see uncommitted changes, you’ll have to open Edit->Settings->Working dir->Diff against working dir. There is committing support, but with a very basic interface. In the Actions menu, you can define custom actions to run other git commands and see their output.



• SmartGIT is a very advanced Git interface that is closed source but free for non-commercial use. I wanted to try this out, but it refuses to run without the Sun/Oracle Java runtime. I didn’t feel like disturbing my OpenJDK installation, and in Ubuntu 11.10 Sun/Oracle Java is no longer supported at all. From the screenshots though, it looks very comprehensive.
• Geany is a simple IDE similar to Gedit. The geany-plugins package in Ubuntu provides GeanyVC, a basic version control plugin for Geany supporting six different VCSs. Once the plugin is enabled, the Tools->VC menu provides simple actions for the current file, directory, and base directory of the repository. The interface is very minimal; viewing any information like the log will open a new document containing raw output from git.



• RabbitVCS provides a set of tools for working with both Git and Subversion. Nautilus file browser and Gedit integration are provided, as well as dialogs for Git actions. I haven’t tested RabbitVCS yet, and the version in the Ubuntu repositories doesn’t support Git. However, instructions and a PPA are available for installing the latest version.

The new upload plugins seem to be very well implemented. To upload to Dropbox for the first time, all I needed to be was click a button in my browser to authorize Shutter’s access to my Dropbox account.

I’ve had Shutter installed for a while, but I haven’t been using it much. However, after taking another look I seem to have solved all my problems with it:

• It’s not obvious how to resize an image, but it can be done with Shutter. Right click on an image, select Run a Plugin, select Resize, and click Run.
• By default Shutter likes to run in the background rather than quitting. Stop this by opening Edit->Preferences->Behavior and uncheck Minimize to tray when closing main window.
• By default Shutter will save every image you capture. To stop it from littering your home directory with files you don’t want, open Edit->Preferences->Main and select Do not save file automatically.

Ubuntu 11.10 and 11.04 both have an older version of Shutter in their repositories. To get version 0.88 with the new upload plugins, you’ll need to follow the directions to add the official Shutter PPA.

• git gui is one of the two official graphical tools available for git. It lets you create commits by staging changes and writing a commit message. There are many more features for remote repositories and branches. The major downside is that the UI and fonts look awful. (Ubuntu package git-gui)
• gitk, the other official tool, allows viewing a repository through the commit log. Selecting a commit shows its details, including diffs for all or a selected file. gitk has the same awful UI as git gui. (Ubuntu package gitk)
• Giggle has a browse view for viewing the repository tree and selecting files to see what commits affected each file and how. The history view is similar to gitk, but with a nice graph view column showing branching and merging. (Ubuntu package giggle)
• Git Cola is a tool similar to git gui for committing and pushing changes. There are buttons for common actions like staging files, pulling, and pushing, as well as an area to write new commit messages. (Ubuntu package git-cola)
• gitg (linked website appear to be down) can both view repositories and make new commits. Its history tab is similar to both gitk and Giggle, but also has graphs showing the amount of changes made to files and a tree view similar to Giggle’s. The commit tab is similar to git gui, but doesn’t have as many advanced features for branches or remote repositories. (Ubuntu package gitg)

gitg is the most promising tool for my purposes. It combines both gitk and git gui-style interfaces in one program. I wish it it had an easy way to push to a remote repository – and there’s only a fetch button that’s tucked away in the File->Repository Properties dialog. [Update It's possible to push after all: right clicking on a branch label in the commit log will show more actions. The branch labels can also be drag-and-dropped on each other.]

It would be nice if the spell checker would skip LaTeX commands. It looks like this issue is being worked on, but is waiting for a patch in the underlying spell-check library. I’ve also noticed that if you’re selecting text while the preview refreshes, the selection gets stuck (bug report).

Ubuntu packages for Gummi are available from the Gummi PPA.

gedit-autotab is a plugin for gedit that solves this problem by automatically changing the indentation settings to match the style detected in each file. The plugin works with gedit 2 (Ubuntu 11.04), and there’s a forked version available for gedit 3 (Ubuntu 11.10).

For gedit 2 / Ubuntu 11.04: Download this archive file and open it. Put the autotab.py and autotab.gedit-plugin files in ~/.gnome2/gedit/plugins (create the plugins folder if it doesn’t exist).

For gedit 3 / Ubuntu 11.10: Download the archive file from this page and open it. Put the autotab.py and autotab.plugin files in ~/.local/share/gedit/plugins (create the gedit/plugins folder if it doesn’t exist).

Finally, open Edit->Preferences->Plugins, and select Auto Tab to activate the plugin. You will get a new item on the status bar showing the current indentation style, which will change depending on the files you open.

ddclient is a dynamic DNS update client which runs in the background periodically checking your external IP address and sending an update to your dynamic DNS provider if it changes. I was ready to edit configuration files and set up a cron job, but none of that was needed because ddclient has a graphical install interface that makes the setup very easy.

I’m using the free version of DynDNS but ddclient also has build-in support for easyDNS, DSLReports, and ZoneEdit.

Search for and install the package ddclient from the Ubuntu Software Center. During installation, you will be prompted for your dynamic DNS provider, credentials for that provider, and the hostname to update. Once ddclient is installed, it should be set up and working.

You can check that ddclient successfully updated your IP by opening Log Viewer, selecting syslog, and looking for a line like ddclient[549]: SUCCESS.

If you want to rerun the install configuration you can do so by running this command:
sudo dpkg-reconfigure ddclient

To change the update period you need to edit /etc/default/ddclient, and change the daemon_interval line for the number of seconds you want between updates:
gksu gedit /etc/default/ddclient

Restart ddclient to make the change take effect:
sudo service ddclient restart

I changed the update period from 300 seconds (5 minutes) to 3600 seconds (1 hour) since my IP address rarely changes. However, there shouldn’t be any problem with frequent updates because ddclient will not make an unnecessary update request when your IP address has not changed.

The main ddclient configuration file is located at /etc/ddclient.conf:
gksu gedit /etc/ddclient.conf

See the ddclient site for more configuration options. The Ubuntu wiki has an extensive page on dynamic DNS.

The main window is a simple list of your remote hosts, which can be grouped into a tree.

New RDP, SFTP, SSH, VNC, and VNC server connections can all be configured using a graphical dialog, complete with advanced options and SSH tunnel support.

Besides having my RDP and VNC/SSH connections saved in the same place, my other favourite feature is the Grab all keyboard events button. When I was using rdesktop to RDP to Windows systems, I couldn’t switch workspaces on Ubuntu because the remote system would grab the key combination. In Remmina, unless I select Grab all keyboard events, workspace switching works fine.

Install Remmina by finding it in the Ubuntu Software Center, or by installing the package remmina:
sudo apt-get install remmina

Google Authenticator is open source, and build upon open standards. The project provides a pluggable authentication module (PAM) which allows the Authenticator to be used to log into Linux systems (without any involvement from Google’s servers). This is useful for providing additional security for remotely-accessed servers. If for whatever reason you don’t want to use a public key authentication for SSH, you can use Google Authenticator instead, although you can’t use both at once.

The Ubuntu 11.10 repository now includes the PAM for Google Authenticator in the package libpam-google-authenticator.
sudo apt-get install libpam-google-authenticator

If you’re running an older Ubuntu release, you’ll have to download and compile it yourself.

After installing, run the google-authenticator application as the user you will access remotely. This will create a key and display a QR code which you can scan using the smartphone app. You will also get some emergency codes for when you don’t have your phone.

Now you will need to enable the PAM for SSH login attempts. Open the file /etc/pam.d/sshd, and add this line:
auth required pam_google_authenticator.so

Next, open /etc/ssh/sshd_config, and change or add the ChallengeResponseAuthentication line so it reads:
ChallengeResponseAuthentication yes

Restart SSH to make the configuration change take effect:
sudo service ssh restart

If you’re setting this up on a remote server, keep your current SSH session open so you can revert the changes if needed. Try to SSH to the system, and you should be prompted for the password and verification code before you are admitted.

Credit to blog.theroux.ca for the instructions on hooking the PAM up to SHH.

If you’re feeling adventuresome, you can even add the auth required pam_google_authenticator.so line from above to other files in pam.d. Adding it to lightdm will cause the login screen to prompt for the verification code. Adding it to login will cause the virtual terminals to also ask for it (but I couldn’t get them to accept a code on my system).

Google Authenticator is useful for SSH servers, but on a desktop or laptop I’m not sure it’s good for much other than impressing your friends. Anyone with physical access to the system can extract the authenticator key from the hard drive. Even if the drive is encrypted, the key has to remain in the clear in order to validate codes.

The preview feature is provided by an application called Sushi. Since GNOME and Ubuntu Unity use the same file browser, no configuration is needed to use Sushi in Ubuntu.

Search for and install gnome-sushi in Ubuntu Software Center, or install it from the terminal:
sudo apt-get install gnome-sushi

Sushi has a plain black user interface, but features nice animated effects when zooming in and out of images, and slick transparent controls over videos. Since Sushi runs in the background once it’s started, it should appear fast when launched.

The file preview feature isn’t very discoverable. The only way to launch Sushi seems to be pressing space while a file is selected.

There seems to be some minor issues with Sushi and Ubuntu’s theme. Also, Sushi doesn’t play very well in VirtualBox. It sort of worked in Unity 2D, but under any compositing window manager it had major problems. I’ll have give it another try once Ubuntu 11.10 is out and I have it installed on a real system.