Category Archives: tutorial

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Software to Record Linux Tutorials by Matt via logo

“My question: what apps do you use to record/stream your desktop while using your camera to insert your face live on the bottom right of your screen?”

desktop-screen-recording

 

Simple Terminal Commands to check 32/64-bit Version and Installed RAM on Ubuntu Computer

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linux-logo

Courtesy of nixpal.com

When you want to check if you have a 32-bit or a 64-bit Linux you can open a Terminal and just type:

file /sbin/init

or

arch

If you prefer to know how much about the RAM you installed on the PC, type:

free -m

or

grep MemTotal /proc/meminfo

for more detailed info you can try:

cat /proc/meminfo

or

grep MemTotal /proc/meminfo

if you prefer to monitor your RAM in real time.

screenshot-bin-bash1

Courtesy of validwebs.com

Configure OpenDNS on your Ubuntu Computer through DDclient in just 6 steps – Tutorial

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1 – Why should I change DNS? 
As for Wikipedia, DNS (Domain Name System) is “a hierarchical distributed naming system for computers, services, or any resource connected to the Internet or a private network… …it translates more readily memorized domain names to the numerical IP addresses  needed for the purpose of locating and identifying computer services  and device with the underlying network protocols. By providing a  worldwide, distributed directory service, the Domain Name System is an essential component of the functionality of the Internet “.
You “use” them in any moment, every time you are in front of a computer but usually you don’t consider to directly manage or change them because you think that it is not worthy to do anything with them. 
On the contrary, you know that many different online companies offer dedicated DNS addresses you can use to substitute the default DNS addresses provided by your ISP.
So, at this point, your main question is “Why should I change DNS on my route or my computer”?
For example, for one or more of these different reasons:
– to have a chance of a possible increasing of speed and reliability when you surf Internet; 
– if you want to delegate to a third “professional” part some security tasks (e.g. third party security filtering to protect yourself against phishing or viruses);
– acces websites that are normally geoblocked by commercial policies/agreements or censorship imposed by Governments;
– parental monitoring if you prefer to have a rough idea of what websites your children visit or if you whant to filter some specific contenents.
2 – Choose a reliable DNS provider
If you decide that you want to try a different DNS provider you need to choose a reliable one. A quick search on Internet will help you to find the most appropriate DNS Provider for your needs.
In this specific case we are examining how to configure the DNS from OpenDNS.com so, if you want to test it, you have to sign up for a free account on opendns.com or simply copy the DNS addresses you find in the bottom right of their homepage or sign up for a OpenDNS.com free account. In the last case, you have the possibility of monitoring your traffic in a professional statistical way and probably you will satisfy one or more of the reasons that may explain your choice to use different DNS. 
3 – Install DNS from OpenDNS on your router
If you want to use OpenDNS on your LAN you have to configure the router through the its configuration interface. The way you can do this varies from one router to another but in all the popular models you will easily find a specific sub-menu where you could activate the “use predefined DNS” option compiling the two addresses provided by OpenDNS.
In this way all your LAN traffic will be pipelined through OpenDNS and you will not need to singularly configure each computer you have.
dns4

Image from: oriental-press.com

4 – Install DNS from OpenDNS on your Linux computer
4a – Preliminary configuration.
The problem with opendns.com is that it doesn’t provide an official tutorial to correctly install its DNS on a Linux machine. For this reason you can follow this brief notes that I wrote after installing it on a Ubuntu 14.04 LTS Ubuntu computer.
Go to the OpenDNS.com support page dedicated to the installation on Ubuntu and follow their instructions:
I exactly followed all the instruction till the point 8 but, when I had big problems when I typed:
sudo ifdown eth0 && sudo ifup eth0
because this message appeared:
ERROR unknown interface eth0=eth0
The matter is that my ethernet is really named eth0 (I double checked using the commands ifconfig and netstat -r -n) but it was not possible to operate on it.
To solve this problem I used the Poorak’s Blog suggestion and I had to open the interface file via Terminal with:
sudo nano /etc/network/interfaces

– or if you prefer: 

sudo gedit /etc/network/interfaces
and manually add these lines:
auto eth0
iface eth0 inet dhcp
then I restarted my networking
sudo /etc/init.d/networking restart
References: [SOLVED] ERROR unknown interface eth0=eth0 on ubuntu
4b – Install DDclient on Ubuntu if you have a dynamic IP
Normally the Internet Service Provides provides a dynamic IP to users that may change over time. So, if you don’t want to pay more to obtain a static IP, you need to install a software that could constantly communicate your actual IP address to OpenDNS.com. In my case, I dedcided to install DDclient to be able to continue to properly use the OpenDNS.com services.
To install DDclient I preliminarly had to install coreutils through Terminal:
sudo apt-get install coreutils
and the required SSH and SSL sockets:
sudo apt-get install ssh libio-socket-ssl-perl
and finally the DDclient:
sudo apt-get install ddclient
At this point you manually edit the configuration file:
sudo nano /etc/ddclient.conf
(or, if you prefer sudo gedit /etc/ddclient.conf)
typing:

##
## OpenDNS.com account-configuration
##
use=web, web=myip.dnsomatic.com
ssl=yes
server=updates.opendns.com
protocol=dyndns2
login=opendns_username
password=opendns_password
opendns_network_label

where:

– ‘opendns_network_label’ is the label given to the network you’re updating in your account.
If you have spaces in your network label, replace them with an underscore ( _ ) 
You can find the network label in the Settings Tab of the OpenDNS Dashboard.
– the login is your email address with OpenDNS
– the password is your opendns password. 
“If you have special characters in your password wrap the password in single-quotes ( ‘ ). 
If there are any single-quotes in your password, put backslash ( \ ) before the single-quote to escape the character”.
References:
– Using DynDNS Protocol to Replace OpenDNS Updater
– How To Install DDclient On Ubuntu (ssh, ssh-perl, ddclient)
5 – Start OpenDNS and DDclient on your Ubuntu computer
At this point you have all the elements to start  so you can open a Terminal and type: 
sudo /usr/sbin/ddclient chkconfig ddclient on && sudo /usr/sbin/ddclient service start
On the other side, if you want to check the status of DDclient, you will type:
sudo /etc/init.d/ddclient status

6 – Configure Linux OS to start DDclient at boot on Ubuntu

On Ubuntu is really simple to configure DDclient to start at the computer boot. You have to open the Session and Startup manager through the desktop Dash. Now you are able to Add a specific command to the Application Autostart menu to run DDclient at the boot:
sudo /usr/sbin/ddclient chkconfig ddclient on && sudo /usr/sbin/ddclient service start
If you are configuring OpenDNS through DDclient on a different Linux distribution you can google the right tutorial or follow the guide created on aboutLinux.info.
At this point you will automatically use OpenDNS on your Ubuntu computer. 
References: Using DynDNS Protocol to Replace OpenDNS Updater

3 things you need to remember when Upgrading to Fedora 23 as for the Unicmen’s instructions

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The upgrade from Fedora 22 to Fedora 23 is not automatic, as usual in my Fedora experience, but it is really simple to manage if you follow the path suggested by Unixmen.

There are few things you need:

– connect your laptop to the power plug (if you use a laptop);

– a couple of hours (something more or less depending on your CPU, RAM, Internet connection speed, etc..);

– few lines of commands on the Terminal

The upgrading process is well structured and to start it you need to launch Terminal and upgrade the native Fedora Fedup with its new version that now is integrated into DNF:

dnf upgrade

Then you have to install the DNF plugin:

dnf install dnf-plugin-system-upgrade

and finally you can start the “core” part of the upgrade just typing:

dnf system-upgrade download –releasever=23 –allowerasing –best

Where:

– allowerasing will continue the upgrade also in presence of any “old” (not yet upgraded) third part repositories that normally would have completely stopped the main upgrading process

-best is a verbose mode in case of unsatisfied dependencies

After a while, depending on your Internet connection speed, you will be able to conclude the upgrade typing:

dnf system-upgrade reboot

Your laptop will reboot and the upgrade starts.

From now you spend more than 40 minutes waiting and answering to few easy questions that the OS asks you to solve some configuration matters.

The length of the waiting time depends obviously on the CPU, the RAM and the type of Hard Disk installed into your PC.

That’s it!

Link

Everything You Know About the Internet of Things is Wrong — Backchannel — Medium

Pandora for “dummies”…. when you are outside the USA… – Firefox, Chrome and Opera add-on –

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The last time I wrote a post about connecting to Pandora  when you are outside the USA was just (sic) three years ago. Meanwhile a lot of things changed and Anonymox, the Firefox add-on and proxy service I suggested in 2012, it is not free now.

It happens but when my nephew asked me something similar and really intuitive to connect to Pandora I was in trouble… more in trouble than I could imagine…. In fact when I started to search something alternative, I found a lot of very good proxy add-ons for Firefox. It was a pleasure to discover some of them because they are technically well done and offer a lot of flexible features for privacy purpose. But this is not the topic of my post… for today.

After many unlucky trials, where I tested different add-ons that were not able to guarantee a minimal rate of usable connection,  I found ProxMate .

ProxMate is an open-source, SSL proxy manager for real dummies. As Firefox add-on you can install it on your browser in just few clicks and then you practically don’t need to configure anything. The only requested thing after installation is to decide the websites and services you want to connect through ProxMate. The internet connection has a good speed rate and the music flows as silk through your Pandora account.

You can install ProxMate searching it through the add-on panel you find in Firefox or you can decide to directly open the link from the  ProxMate website. After the installation ( no restart required) you have to find the “shark fin” icon into your Firefox bar. If you don’t find it immediately, you have to manage your icons and manually personalize the bar.

Then, click on ProxMate “my button” icon and select: “Install New Packages”. You are redirect to the ProxMate website where you can select Pandora or others interesting websites (e.g. Netflix, iHeart Radio, etc..) with specific IP restriction policies. 

Now, you select your desired website/service and follow the instructions (click selection) that will appear on the screen to complete the installation.

Last but not least, don’t forget to click again on the ProxMate icon and enable the proxy service.

As usual, I recommend to NOT forget to disable  ProxMate (as every other proxy server) when you don’t need to use it.

Oops, I forgot to say that ProxMate is free of charge……. Enjoy it!!

——————

References:

https://addons.mozilla.org/it/firefox/addon/proxmate/?src=search

https://proxmate.me/

Hibernate for Ubuntu

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Since the Ubuntu 12.04 LTS the hibernate icon disappeared as possible option at the shutdown. It is not a big loss if you are not used to use (or overuse) it as I often do. Personally I think that the hibernate feature is really useful when you want to freeze your computer maintaining all the windows -and the work- you are working on at a precise moment. 

Ubuntu decided to “cut” this particular command from its GUI because it registered a remarkable number of problems caused by hardware conflicts in modern computers. 

If you use Ubuntu and you think that hibernate could till be useful for you (especially during busy working days), it is possible to insert again this specific feature as GUI on your Desktop.

First of all you have to test if your computer contains the right hardware for “hibernate” so open Terminal and type:

sudo pm-hibernate

The computer will hibernate itself but you have to reboot it to understand if hibernate worked properly in your case.

I hope (as it was for my PC) that all has gone well. In this case you can start to create the dedicated icon on your upper bar.

Before of starting it’s necessary to understand that the hibernate command will use the SWAP partition to save your temporarily data. Usually it is recommended to have a SWAP partition with, at least, the double of space of your RAM.

So I suggest to install Gparted to check the SWAP space and, only if necessary, increase your SWAP partition reducing the primary partition. Please, do this only after you safely backup all the data in your computer because this procedure could be risky if you are doing it for the first time and you have not enough experience:

sudo apt-get install gparted

Open a Terminal and install gedit and gksu (if you don’t have them already installed on your machine) typing:

sudo apt-get install gksu && sudo apt-get install gedit
Then type:
sudo gksu gedit /etc/polkit-1/localauthority/50-local.d/com.ubuntu.enable-hibernate.pkla
Now a blank gedit document, named enable-hibernate.pkla will appear on your screen.

Copy and paste the following text to “compile” it:

[Enable Hibernate]

Identity=unix-user:*

Action=org.freedesktop.upower.hibernate

ResultActive=yes

Save it and reboot your computer.

A new icon will appear on the right corner of the upper bar. When you click on it, a Terminal window will appear asking for the system password. Type it and click on Return and your PC will immediately hibernate. 

Good busy working days!

—————-

References:

http://www.howtogeek.com/113923/how-to-re-enable-hibernate-in-ubuntu-12.04/

http://askubuntu.com/questions/49095/how-do-i-add-more-swap-easily-so-that-i-can-hibernate-my-laptop#49162

https://help.ubuntu.com/community/SwapFaq

http://askubuntu.com/questions/29783/so-what-is-the-reason-behind-the-claim-that-you-need-at-least-as-much-swap-area#29809

How to delete – double – icons on your Android smartphones!

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Google Play StoreThe first time I noticed doubled icons appearing on my Android 4.4 smartphone I thought that it was a temporary problem. So I tried to solve that with a simple reboot but I didn’t succeed.

Moreover when I tried to delete just one of the doubled icons I uninstalled the App…. This kind of matter is typical of smartphones and it usually doesn’t happen on tablets or Android PCs where you have a dedicated room (the “menu” page) to uninstall software (Apps) and different “screens” to organize them.

This means that if you delete a App’s icon from one of the “screens” you will still have your software installed into your device. The problem of double icons on smartphones is caused by a wrong configuration of your personal settings on Google Play Store.

To solve it, you have to:

1 – find all the problematic Apps;

2 – go to Google Play — Settings – and deselect “Add icon to home screen”;

3 – uninstall the “problematic” Apps;

4 – reinstall them.

To conclude it’s better to solve this kind of problem as soon as you notice it because, to solve the matter, you will have to waste your time uninstalling and reinstalling all the Apps with doubled icons.