How To: Fix “Failed to download repository information Check your Internet connection.”

Hi folks,


Some days ago I had a problem with my ubuntu update manager, it was displaying a error message and the update manager was not working.



So I googled it and find the solution here.


Run in the terminal to search the broken repository

sudo apt-get update


The broken repository should appear like this



Now just go to System > Administrator > Update Manager, click on button on the windows bottom Configuration, Click the Other Software tab.

Find the repositories which caused the failure on the update and uncheck them and then close the Software Centre.


Run, once again and should work:

sudo apt-get update



Thats it folks


Como instalar Latex no VIM

Olá pessoal

Alguns dias atrás eu tive que instalar o Latex para escrever minha tese, é bastante simples, basta instalar os seguintes pacotes:

sudo apt-get install tex-common texlive-base texlive-base-bin texlive-common texlive-doc-base texlive-latex-base texlive-latex-extra abntex

O editor que texto que eu utilizo é o VIM e para uma referência biliográfica organizada recomendo o Texmed.

É isso pessoal


Android not to index multimedia files/directory

Hi folks


Today I had the problem with my cell phone (Samsung Galaxy – Android), I want some files in a specific folder to not be indexed in the albuns and players.

The solution I found is very simple:

  1. Create a file named .nomedia in the folder you want to not be indexed (observe the dot)
  2. Reboot the cell phone


This is very simple but how to create a file is not that simple once you dont have the root access (if you want to use the terminal in phone), however you can workaround this problem:

  1. Create the file in the PC (in linux: touch .nomedia)
  2. Connect the cellphone to the PC via Kies air or USB cable
  3. Move/Copy the file from PC to the folder you want to not be indexed
  4. Reboot the phone


IMPORTANT NOTE (nomedia bug): I recommend you to create the .nomedia file PRIOR to files input because when I created AFTER did not work and the files still was indexed in the gallery.

Observation: This procedure will make the files to not be indexed in the multimedia (albuns and players) softwares but will not to hide the files, this files will be available by fold manager


Thats it



Inkscape arrowhead color (Bug)

Hi folks,


Some days ago I fought against my Inkscape because I did not want black arrow, the problem is that once you paint the arrow, the arrowhead remains black like this:



This is a know inkscape bug, however I lost some hours seeking for a answer.


The solution:

- Use an extension to circumvent the problem


How to do it:

  1. Paint the arrow the color you want
  2. Click (for selection) in the arrow you want, then
  3. Apply the extension



So you will get the arrow the colour you want


Thats it folks


How to set a music to notification sound in Android

Hi folks,


Today I wanted to set a music to be my notification sound in my Android Smartphone, I read many tutorials but the solution I found dont need any software instalation so is the most simple one.

  1.  Choose the desired song, you can download it from youtube or so (I recommend to use this site for the MP3 extraction/download)
  2. Save it on the /sdcard/media/audio/notifications/
  3. Go to the selection notification sound selection (Configuration -> Sound -> Notification Sound) the music you have put must be displayed in the list


Thats it




How to create Favicons

HI folks,


Today I had to create a favicon to use in a website that I was developing. The problem was that any of the tutorial that I was using was not really good, so I have founded a simple solution by my own.

In two simple steps:


1) Use the Inkscape to make the draw:

  • Use a 16 X 16 pixels a template (A good hint is to use a transparent background)
  • Export and save it as .png

Remember that favicon as very small and you will need a very simple and informative image.


2) Use the imagemagick to convert .png in .ico


If you need to install the program (probably you already have it installed if you use Ubuntu)

sudo apt-get install imagemagick


To run the convertion, just use:

convert <image_name>.png <icon_name>.ico


SSH Tunneling

Hi Folks,

From now on I will need to use the SSH by tunneling to connect from my Home machine (Client) to my Office machine (Server) through a SSH Gateway because my Office machine is not directly connected to the Internet anymore, it seems a little bit complicated but I will try to simplify the things.

First of all the scheme to guide those who still may not have understood:

To access/connect the server I want, I can do by 2 ways:

    1. Connect to the SSH Gateway and then, connect to the desired server, it is the simplest solution but become quite costly and annoying when you need the SSH or SCP often, especially the SCP because you must copy to a tmp directory of the SSH Gateway all the files you want and then copy to desired server.


    1. Open a port in the client machine that connects to the desired server directly by tunneling, may seem more complicated but worth it. I will show how to do it bellow.


How to open the tunnel:

ssh -p <SSH_port_in_SSH_gateway> -fN -L <Port_to_use_in_client_machine>:<Server_IP>:<SSH_port_in_Server> <user>@<SSH_Gateway_IP>



ssh -p 22 -fN -L 6666: my_user@


How to use the tunnel – SSH:

ssh -p <Port_to_openned_in_client_machine> <user>@localhost



ssh -p 6666 my_user@localhost


How to use the tunnel – SCP:

scp -P <Port_openned_in_client> <user>@localhost:<file_to_be_coppied_in_server> <file_destination_in_client>


example 1 (copy from server):

scp -P 6666 my_user@localhost:/home/my_user/Desktop/foo /home/my_user/Desktop/


example 2 (copy to server):

scp -P 6666 /home/my_user/Desktop/foo my_user@localhost:/home/my_user/Desktop/


That’s it folks


Thanks to my friend Marcelo Gomes, who gave me the tips: Marcelo’s Blog (Blog in portugueses).

Chrome PDF browser viewer problem

Hi folks,

Sometimes I have the problem with the “Chrome PDF Web Viewer”, it display the content wrongly. The solution I found is to disable this feature, its quite simple.

Just go to Chrome Plug-ins preferences, by typing at the URL:


and disable this feature like it shows in the image bellow

By doing this the PDF will be downloaded like a normal file and you can use the Viewer of your
preference e. g.: Adobe Reader.

Thats it