Encrypt files with GnuPG

Here is a simple and quick way for you to encrypt files in Linux:

gpg –output doc.gpg –encrypt –recipient EmailofRecipient@blah.com original_file.doc

Further explained:

  • –output (or -o) is the name of the encrypted file
  • –recipient (or -r) is the person who will be decrypting the file. If the file is for yourself only, use the email address of your GPG key.

To decrypt:

gpg --output output_file.doc --decrypt doc.gpg

I recently used this to encrypt a sensitive file before placing it on my Dropbox account. Nice safe way to place a private document in the cloud.

Reference, GnuPG manual.

Tip: discover and terminate high CPU processes (Linux)

A quick tip to get the dust out of our blog 🙂

If you hear the fan of your computer going way up, most likely that was because some application or process is using too much CPU. Find out which one and terminate it by:
1. Open the terminal
2. Run “top”
3. Press “k” and the number on “pid” column of the process which appears on the top of the list.

Gwibber microblogging app now 2.0 [Linux]

Gwibber, an open source microblogging app for Gnome has now reached version 2.0!

Although at 2.0, the developers are not considering this a stable release yet and not making it available on the stable distribution channels. What I could notice first from the upgrade was the UI from:


Gwibber 2.0

Which means:

  • it is now easier to jump between different accounts (Gwibber supports Identi.ca, Twitter, Facebook, Digg, StatusNet, Flickr and more).
  • You can easily post to only one account.
  • Easy “re-dent” / “re-tweet”.

I’m sure there are more behind the scenes improvements but so far I haven’t seen any list. For now, the upgrade was worthwhile.

Arora – completely FLOSS Webkit browser

If you want to run a WebKit web browser with no strings attached (unlike Safari and Google Chrome), Arora is surely worth a try.


First plus is that it runs on Linux, Windows and MacOS X. It is fast, has private browsing and looks like it has some plug-in support. Another good news is the announcement Kubuntu will carry Arora as its default browser in the 9.10 release.

Pidgin now supports audio and video

One of the “I thought it would never come” moments in the open source software industry would be audio and video support in Pidgin. Now it is here! Almost… Windows is not yet supported.

With the release of Pidgin 2.6.1. audio and video is finally supported in the xmpp protocol (used by GTalk). I have to say I haven’t tried it yet since my default IM client is now Empathy (already having audio and video support), which will be the default multi-protocol IM client for the Ubuntu 9.10 release.

Hurray for the release of the new feature! I’m pretty happy for it since it might place a dent in the market share Skype has for VoIP and could make Pidgin more popular for Windows users in comparison to other proprietary solutions.

Compare files in Linux

Not long ago I was working with some .po files and needed a nice and simple diff program to merge 2 files. First I tried the multi-purposed text editor vim.

Using vim as a diff and merge tool:

with Andrej’s article I found some nice tips & tricks and the Vim manual for diff tasks. Some useful commands,

  • vim -o one.txt two.txt three.txt” (for horizontal split), “vim -O one.txt two.txt three.txt ” (for vertical split)
  • go to the next diff point   ” ]c “; go to previous diff point “ [c
  • merge to original “do“, merge from original “dp“.

The window you’ll be looking at will look something like this:


Where text highlighted red will display text which doesn’t match from the files being compared.

Another tool I found was Meld. This program was incredibly simple to use and visually simple to work with.

Using Meld Diff Viewer:

  • open the files (or directories) which you’d like to compare;
  • you will visually see where on the original file the text is at on the other file(s) being compared. Specially useful if the text in the files you’re comparing are in completely separate lines;
  • clicking on arrows between the files being compared, the text will go to or from the original file.



if you’re working on the command line, vim will do the job quite nicely but can be troublesome to inform you if text in both files are the same but spaced out in different line numbers. On the other hand, Meld was the tool I used for the task since there was basically no learning curve to get started and it displayed very well differences and matches in the file even if text were separated by dozens of line between both files I was comparing.

Emacs – text editor on steroids

Although it has been a round for quite some time, I’m not a coder so my experience with text editors and IDEs is very limited. To give you an example, I’ve been using on the command line the good-ol’ simple nano. But, since I’m starting to need a bit more powerful features, my search began for a more powerful program.

Emacs was my first try since it has been highly rated and praised. For me, there was a bit of a learning curve for the simple operations of navigating through a file (keyboard shortcuts are awesome) but nothing overly complicated and there is a nice tour accessible when you open the program.


My usage so far has been to compare and diff a file, but soon I’ll also encounter tasks such as merge and simple code debugging. Again, I’m not a coder so this tool right now might be an overkill but who knows in the future… better get myself familiar from the start with a nice program than having to learn again something new later.

Ebook reader and manager

For those who like ebooks, Calibre is a great program that was created to manage pretty much any aspect of your reading files.


The list of features is pretty extensive:

  • convert files from and to epub, mobi, LRF and supports input of several other formats including PDF, html, odt, rtf amongst others;
  • syncs to mobile reader devices (seems to work well with the iPhone/Stanza and the Kindle);
  • convert a news feed to an ebook;
  • scans your computer to check for all supported ebook formats so you can keep them organized, download cover art and meta data;
  • runs on Windows, Linux and MacOS X.

At the present moment the app is on version 0.5.3 and seems to be under heavy development. For me, file conversion from PDF to epub format went without any hitches and I was finally able to organize my ebook library under one program.

Import and edit PDF files in OpenOffice

For quite a while now OpenOffice has been promising the ability to import and edit PDF files. Although not released with the program itself, you can grab the Sun PDF Import extension to do just that.

This extension is in beta and is available multi-platform for Windows, Linux and MacOS X systems.

Tests that I ran were pretty good. The text in the PDF file is imported well and in a way I could edit the text, font settings and images. There was a small problem in that the document that was shown to me had colors inverted (black background with white font). But, don’t ask me why, the imported file actually contained 2 layers. Deleting the one on top will show you the layer with correct colors and fully editable.

The extension is in beta but it is sure worth a try and beats editing the PDF through an image software like I used to do.

New Android 1.5 (Cupcake)

The last time there was an Android upgrade, I had to wait over 1 month to get mine. Fortunately this time it appears Europe had Android 1.5 launch date before users in the U.S. This is a much expected release because of the extensive list of new features.

Without further delay, here is the tour of what is new in Android Cupcake.


First, here is my home screen where you can add shortcuts, widgets and live folders:


We now have the new widgets Calendar and Music. In the “shortcuts” category, to be honest I had never used it before but here also goes a screenshot of what is offered:


I really enjoyed the calendar widget although I wish I could expand it a bit more to display more event information. Your music widget will display a cute little bar with the song currently playing or the option for you to select a playlist to start playing on your device.


Next cool feature is video recording!


The videos you record on the Android can be pushed directly to YouTube now with 2 simple clicks. A nice way for Google to tie its services well.

Next comes the soft-keyboard! I’m still struggling to get used to this new keyboard, it is so tiny compared to the ‘full sized’ one on the G1.


But, there is a very nice feature of suggested words. So, as you type the system tries to identify the word you wish to write and even if you get lost typing incorrect keys it still picks up misspellings quite well to suggest the correct word.

A nice little extra is automatic screen orientation. On the G1 you were able to get landscape view only once the keyboard was open. But, with new Android devices coming out soon without a keyboard, orientation was adjusted to how you’re holding the phone.


Last but not least, a few cosmetic changes were made. The background of the app menu is no longer transparent and the pull-down status menu had some minor visual improvements as well.


Unfortunately I couldn’t test the stereo bluetooth since the headset I used with my Nokia N96 was still not recognized.

Like mentioned, a whole lot of new things and that is not all, there is still:

  • browser improvements (latest Webkit browser & Squirrelfish Javascript engines);
  • Linux kernel (version 2.6.27);
  • Upload photos on Picasa;
  • native video playback (MPEG-4 & 3GP formats).

The complete change log can be found here.

Unfortunately not everything is perfect… Loading some apps and going back to my home screen takes a bit longer than before.  Plus, for some reason at times the app list gets loaded on-the-fly and I have to wait a few seconds for everything to get loaded and sorted alphabetically.

Overall, Cupcake is an awesome release and Android is now in a much better position to be released on more mobile phones and (rumors have it) netbooks!