Pathin.org - a software developer's life http://www.pathin.org Mon, 30 Jan 2012 09:26:13 +0000 en hourly 1 http://wordpress.org/?v=3.3.1 Debian 6 – HowTo enable gnome root login on Debian 6 (Squeeze) http://www.pathin.org/tutorials/debian-6-howto-enable-gnome-root-login-on-debian-6-squeeze/ http://www.pathin.org/tutorials/debian-6-howto-enable-gnome-root-login-on-debian-6-squeeze/#comments Mon, 30 Jan 2012 09:25:45 +0000 pathin http://www.pathin.org/?p=205 Debian logoHello, in this short tutorial I will show you, how you can enable root login on the gnome login screen on Debian 6 (Squeeze).

How to enable gnome root login on Debian 6?

Note:
You will need the root password for this set of commands.

Step1:

Login to a user account.

Step2:

Open a terminal window and type this into your window:

su root
gedit

Step3:

Now open the file /etc/pam.d/gdm3 and comment out the fifth line:

#auth   required        pam_succeed_if.so user != root quiet_success

/etc/etc/pam.d/gdm3

#%PAM-1.0
auth    requisite       pam_nologin.so
auth    required        pam_env.so readenv=1
auth    required        pam_env.so readenv=1 envfile=/etc/default/locale
#auth	required	pam_succeed_if.so user != root quiet_success
@include common-auth
auth    optional        pam_gnome_keyring.so
@include common-account
session required        pam_limits.so
@include common-session
session optional        pam_gnome_keyring.so auto_start
@include common-password

Step4:

Reboot.

I hope this helps some of you, because root is not allowed to login on a fresh Debian 6 installation.

]]> http://www.pathin.org/tutorials/debian-6-howto-enable-gnome-root-login-on-debian-6-squeeze/feed/ 0 Debian 6 – HowTo enable sudo on your user account on Debian 6 (Squeeze) http://www.pathin.org/tutorials/howto-enable-sudo-on-user-account-debian-6-squeeze/ http://www.pathin.org/tutorials/howto-enable-sudo-on-user-account-debian-6-squeeze/#comments Fri, 13 Jan 2012 12:38:44 +0000 pathin http://www.pathin.org/?p=187 Debian logoHello, in this short tutorial I want to show you, how you can run programs with root rights on your freshly generated user account, by adding the sudo command to user accounts.

What is sudo?

sudo – short for “substitute user do” – is a command which allows users to run commands with other user’s rights (e.g. root).

How to enable sudo for my user account on Debian 6?

Note:
You will need the root password for this set of commands.

Step1:

Login to a user account.

Step2:

Open a terminal window and type this into your window:

su root
adduser YOURUSERNAME sudo

Step3:

Now reboot, and on your next session you will be allowed to run every program or command, which doesnt belong to you, or you don’t have the rights for with:

 sudo COMMAND

I hope this helps some of you, because sudo isn’t automatically added to your user account on a fresh Debian 6 install.

]]> http://www.pathin.org/tutorials/howto-enable-sudo-on-user-account-debian-6-squeeze/feed/ 0 jQuery Tutorial http://www.pathin.org/tutorials/jquery-tutorial/ http://www.pathin.org/tutorials/jquery-tutorial/#comments Fri, 09 Dec 2011 14:30:22 +0000 pathin http://www.pathin.org/?p=180 Hello, I just decided to write a little jQuery Tutorial, with some examples.

Demo 1: Alert Box

First, we register a so called: “ready event” for the document.
In jQuery we do this with: $(document).ready(function()).
In the source code it would look like this:

$(document).ready(function() {
    //Do something, when the document is loaded.
});

The complete source code looks like this:

Demo 1: Alert Box – Example: That’s what it looks like

<html>
	<head>
		<script src="jquery.js" type="text/javascript"></script>

		<!--Code for Demo 1-->
		<script type="text/javascript">
		$(document).ready(function(){
			$("a").click(function(){
				alert("Hello World");
			});
		});
		</script>
	</head>
	<body>
		<p><a href="#">A link</a></p>
		<p><a href="#">Another link</a></p>
	</body>
</html>

Now let’s have a look, what we have done. $(“a”) is a jQuery selector. With $(“element”) we can select different things. We can select classes (“.classOfElement”) or ID’s $(“#idOfElement”). But we also can combine this, to for example select all divs with the class development: $(“div.development”).

In our case we select all link (a) elements in our document and with click() we add a click event to all selected elements. In our case a normal javascipt function is called then: alert(“Hello World”). So now, what happends at this function? When klicked on an a element in our document, it calls a MessageBox with the text: “Hello World”. That’s exactly what we wanted.

Demo 2: CSS Classes

Another thing jQuery can do is to add and remove css classes. First we create in css a class called: test. In this case let’s take a bold and italic font.

a.test {
    font-weight: bold;
    font-style: italic;
}

Let’s go over to javascript. When the document is loaded, the class test should be added to all links.
For this goal, we take the previously learned function $(document).ready(function()). With $(“a”) we select all a elements and with the function addClass() we add a class to them. In our case it’s the class test.

$(document).ready(function(){
    $("a").addClass("test");
});

Let’s add a few more links for testing and we will see what happends.

Demo 2: CSS Classes – Example: That’s what it looks like

<html>
	<head>
		<script src="jquery.js" type="text/javascript"></script>

		<!--Create CSS class "test" bold and italic -->
		 <style type="text/css">
			a.test { font-weight: bold; font-style:italic;}
		 </style>

		<!--Code for Demo 2-->
		<script type="text/javascript">
		$(document).ready(function(){
			$("a").addClass("test");
		});
		</script>
	</head>
	<body>
		<p><a href="#">A link</a></p>
		<p><a href="#">Another link</a></p>
	</body>
</html>

Let’s have a quick look at the site. We see that all links are bold and italic. So the class test was added to them.

jQuery has some special effects, which we will use now. They make some very nice eyecandy without much trouble.
First, let’s create a simple div container with some text in it.

    <div style="background-color:#336699;color:#fff;">
		I'm a textbox and have alot of work to do :)
	</div>

I’ve set the background via style attribute to blue and the font color to white, that we can see the box a little better.
Now, let’s add a link, that should do something with that box.

<a href="#" id="shrink">Shrink the box! (80 x 120px)</a>

I added the id shrink to the link, so we can later select this link with jQuery.
Now, lets add some javascript. I want the link to do something with the box, when we click it.

$(document).ready(function(){
	/*Shrink box*/
		$('a#shrink').click(function(){
		$('div').animate({ height: 80, width: 120 }, "slow", function(){});
	})
});

With $(“a#shrink”) we select our previously created link and add the click event to it. Like previously on a click the javascript code in the brackets is executed.
In the next step we select the element, that should be changed in some way, in our case it’s $(“div”), which means that we select all div elements. We can animate objects with the function animate. Animate has different properties. In our case we set the height to 80px and the width to 120px, we want the effect to be slow, that’s why we added a slow.

Demo 3: Special Effects – Example: That’s what it looks like

<html>
	<head>
		<!-- Load jQuery framework -->
		<script src="jquery.js" type="text/javascript"></script>

		<!--Code for Demo 3-->
		<script type="text/javascript">
		$(document).ready(function(){
			/*Shrink box*/
			$('a#shrink').click(function(){
				$('div').animate({ height: 80, width: 120 }, "slow", function(){});
			})
			/*Enlarge box*/
			$('a#enlarge').click(function(){
				$('div').animate({ height: 200, width: 800 }, "slow", function(){});
			})
			/*Hide and Show*/
			$("a#slideFade").toggle(function(){
				$("div").animate({ height: 'hide', opacity: 'hide' }, 'slow');
			},function(){
				$("div").animate({ height: 'show', opacity: 'show' }, 'slow');
			})
		});
		</script>
	</head>
	<body>
		<div style="background-color:#336699;color:#fff;">
			I'm a textbox and have alot of work to do :)
		</div>
		<p><a href="#" id="shrink">Shrink the box! (80 x 120px)</a></p>
		<p><a href="#" id="enlarge">Enlarge the box! (200 x 800px)</a></p>
		<p><a href="#" id="slideFade">Hide/Show the box!</a></p>
	</body>
</html>

I’ve added two more links and just like in the previous example i added some more effects. The only thing that differs from the rest is link number 3. It executes another function on the second click, than on the first. On the first click it made the box hide and on the second click it made the box show again. To archieve this, i used the function toggle. You can add as much functions (in rows) as you want to toggle, which will be executed all row by row and when it’s done restart from the beginning.

The best is to have a look at the example site and to try it for yourself.

Other jQuery tutorials:

German translation by d4nza: jQuery Tutorial

]]> http://www.pathin.org/tutorials/jquery-tutorial/feed/ 3 Java / Cassandra – Fix: Cannot support TLS_RSA_WITH_AES_256_CBC_SHA with currently installed providers http://www.pathin.org/tutorials/java-cassandra-cannot-support-tls_rsa_with_aes_256_cbc_sha-with-currently-installed-providers/ http://www.pathin.org/tutorials/java-cassandra-cannot-support-tls_rsa_with_aes_256_cbc_sha-with-currently-installed-providers/#comments Fri, 18 Nov 2011 18:26:34 +0000 pathin http://www.pathin.org/?p=140 Today I was playing around a little with apache cassandra, setting up internode encryption with keystore and truststore, following the tutorial in the cassandra.yaml file. But I always ended up getting the error message: Cannot support TLS_RSA_WITH_AES_256_CBC_SHA with currently installed providers.

How to fix this Error

Full error message

java.lang.IllegalArgumentException:
Cannot support TLS_RSA_WITH_AES_256_CBC_SHA with currently installed providers
at com.sun.net.ssl.internal.ssl.CipherSuiteList.(CipherSuiteList.java:79)
at com.sun.net.ssl.internal.ssl.SSLServerSocketImpl.setEnabledCipherSuites(SSLServerSocketImpl.java:166)
at org.apache.cassandra.security.SSLFactory.getServerSocket(SSLFactory.java:54)
at org.apache.cassandra.net.MessagingService.getServerSocket(MessagingService.java:255)
at org.apache.cassandra.net.MessagingService.listen(MessagingService.java:241)
at org.apache.cassandra.service.StorageService.joinTokenRing(StorageService.java:485)
at org.apache.cassandra.service.StorageService.initServer(StorageService.java:462)
at org.apache.cassandra.service.StorageService.initServer(StorageService.java:383)
at org.apache.cassandra.service.AbstractCassandraDaemon.setup(AbstractCassandraDaemon.java:215)
at org.apache.cassandra.service.AbstractCassandraDaemon.activate(AbstractCassandraDaemon.java:337)
at org.apache.cassandra.thrift.CassandraDaemon.main(CassandraDaemon.java:107)

Solution

Note: I’m using jre6 on Debian Squeeze and jre7 on Windows 7 64-bit, it may differ on other distributions or operating systems

This error message has to do with missing or corrupt java security libraries.

1. Locate your jre lib/security directory

On Linux it should be by default: /usr/lib/jvm/java-6-sun-1.6.0.26/jre/lib/security/
On Windows it should be by default: C:\Program Files\Java\jre7\lib\security

2. Download the Java Cryptography Extension (JCE)

Download for Java 6: http://www.oracle.com/technetwork/java/javase/downloads/jce-6-download-429243.html
Download for Java 7: http://www.oracle.com/technetwork/java/javase/downloads/jce-7-download-432124.html

3. Install the JCE

Extract the downloaded zip and place the two .jar files US_export_policy.jar and local_policy.jar into your jre/lib/security folder and overwrite old files if any.

Done

You are done. Your application should now start up normally.

]]> http://www.pathin.org/tutorials/java-cassandra-cannot-support-tls_rsa_with_aes_256_cbc_sha-with-currently-installed-providers/feed/ 0 Ubuntu 11.10 / Debian 6 – Build newest Pidgin from source http://www.pathin.org/tutorials/ubuntu-11-10-debian-6-build-newest-pidgin-from-source/ http://www.pathin.org/tutorials/ubuntu-11-10-debian-6-build-newest-pidgin-from-source/#comments Mon, 07 Nov 2011 22:56:11 +0000 pathin http://www.pathin.org/?p=79 This tutorial wraps up how to build and install the newest version of the famous multi-chat-messenger Pidgin on Debian 6 – “Squeeze” and Ubuntu 11.10 – “Oneiric Ocelot”.

Note:

This tutorial was only tested with the following distributions:

  • Ubuntu 11.10 – “Oneiric Ocelot”
  • Debian 6 – “Squeeze”

but it may work with any other Debian or Ubuntu based distribution like Linux Mint.

What is Pidgin?

Pidgin is a multi-chat program which has the feature to log you in to various multiple chat networks on your Linux system.
This means that you can chat with your friends on MSN (Windows Live Messenger), Yahoo (Yahoo Messenger), ICQ, xFire (with the plugin: gFire), and various other networks at the same time.

How to build and install pidgin

As previously mentioned, this tutorial was written for Ubuntu 11.10 – “Oneiric Ocelot” and Debian 6 – “Squeeze”.
It might differ for other distributions.

Note for Debian:
On Debian, your user account doesn’t get added to the sudo group by standard.
If you haven’t done so already, please add your user account to the sudo group and reboot:

su root
adduser YOURUSERNAME sudo

Let’s get rolling!

Step 1: Preperations

To be able to compile and install pidgin from source, we need to get sure, that we meet all the dependencies.
Open a Terminal Window
This can be done by running the following commands:

sudo apt-get build-dep pidgin

This will add all the dependencies needed to build pidgin from source.

Step 2: Download and prepare compiling

Next step is to download the source itself.
For this tutorial i will refer to the version: 2.10.0 with the packet name: pidgin-2.10.0.tar.bz2
Open a new Terminal Window
To download and unpack pidgin-2.10.0.tar.bz2 type in the following:

cd /tmp/
wget http://sourceforge.net/projects/pidgin/files/Pidgin/2.10.0/pidgin-2.10.0.tar.bz2
tar -xjvf pidgin-2.10.0.tar.bz2
cd pidgin-2.10.0/

this will create a new folder called “pidgin-2.10.0″, we just changed into this folder.

Step 3: Compile and install pidgin

First of all we need to run the configure script, which is checking if all the dependencies we installed in Step 1 are met.
To do this run the following command inside the pidgin-2.10.0 directory, which we are in already:

./configure

If the script returns “configure complete, now type ‘make’” we are fine. If not, please recheck the dependencies!
Let do this!
Insert make into the terminal window.

make

Pro Tip:
If you have more than one core, you can speed this step up by typing:

 make -j YOURNUMBEROFCORES

This might take a while, feel free to grab some coffee.
Now, it’s time to finally install pidgin.
Insert this into the terminal window:

sudo make install

This will install pidgin into the correct directories, set the correct chmod flags and sets up the Unity/Gnome menu entries.

Step 4: Start Pidgin

To make Pidgin appear in the menus, run the following:

For Debian:

sudo /etc/init.d/gdm3 stop

Now you have a black screen.
Press: Alt+F1 to switch to a terminal window and login.
When you are logged in, type the following:

sudo /etc/init.d/gdm3 start

Now Login.
Pidgin will now appear in: Applications->Internet

For Ubuntu:

sudo service lightdm restart

Pidgin is in your Dash now.

If it doesn’t you might want to restart your ldm/gdm and/or reboot, you can start pidgin from a terminal window:

pidgin

We are done!

You are free to delete the directory you installed pidgin from now or move it somewhere else if you like to.

Localized versions of this tutorial

German by d4nza:
http://d4nza.de/blog/tutorials/ubuntu-11-10-debian-6-%E2%80%93-kompilieren-der-neusten-pidgin-version-vom-source-code

]]> http://www.pathin.org/tutorials/ubuntu-11-10-debian-6-build-newest-pidgin-from-source/feed/ 2 Ubuntu 11.04 – Build Pidgin from Source http://www.pathin.org/tutorials/ubuntu-11-04-build-pidgin-from-source/ http://www.pathin.org/tutorials/ubuntu-11-04-build-pidgin-from-source/#comments Mon, 13 Jun 2011 02:17:28 +0000 pathin http://pathin.org/?p=45 This is an old version. See the new Version here:
http://www.pathin.org/tutorials/ubuntu-11-10-debian-6-build-newest-pidgin-from-source/

Many people seem to be struggeling with installing Pidgin from source.
That’s why I decided to write a little tutorial about how to build and install the famous “Instant Messenger” Pidgin from source.

What is Pidgin?

Pidgin is a chat program which lets you log in to accounts on multiple chat networks simultaneously.
This means that you can be chatting with friends on MSN, talking to a friend on Google Talk, and sitting in a Yahoo chat room all at the same time.

How to build and install pidgin

This tutorial is written for Ubuntu 11.04 – Natty Narwhal and might differ for other distributions.
If you have problems, following this tutorial, please be kind and drop a little comment!

Step 1: Preperations

To be able to compile and install pidgin from source, we need to get sure, that we meet all the dependencies.
This can be acomplished by running the following command from the Linux Terminal:

sudo apt-get build-dep pidgin

This will add all the dependencies needed to build pidgin from source.

Step 2: Download and prepare compiling

Next step is to download the source itself.
Go to the Pidgin download site: http://www.pidgin.im/download/source/, download the newest version and save it to your personal home folder. (In my case it’s /home/pathin)
For this tutorial i will refer to the version: 2.8.0 with the packet name: pidgin-2.8.0.tar.bz2
Open a new Terminal Window
To unpack pidgin-2.8.0.tar.bz2 type in the following:

cd ~/
tar -xjvf pidgin-2.8.0.tar.bz2

this will create a new folder called “pidgin-2.8.0″.
Let’s change into this folder:

cd pidgin-2.8.0/

Step 3: Compile and install pidgin

First of all we need to run the configure script, which is checking if all the dependencies we installed in Step 1 are met.
To do this run the following command inside the pidgin-2.8.0 directory:

./configure

If the script returns “configure complete, now type ‘make’” we are fine. If not, please recheck the dependencies!
Let do this! Insert make into the terminal window!

make

This might take some while, feel free to grab some coffee.
Now, it’s time to finally Install pidgin.
Insert this into the terminal window:

sudo make install

This will install pidgin into the correct directories, set the correct chmod flags and sets up the Gnome Menu Entries.

Step 4: Start Pidgin

At standard Pidgin should appear at Applications -> Internet -> Pidgin.
If it doesn’t you might want to restart your XServer or reboot.
Alternatively you can start pidgin from a terminal window:

pidgin

We are done!

You are free to delete the directory you installed pidgin from now or move it somewhere else if you like to.

Links:

German Translation by d4nza:
http://d4nza.de/blog/tutorials/ubuntu-11-04-%E2%80%93-pidgin-vom-source-code-kompilieren/

]]> http://www.pathin.org/tutorials/ubuntu-11-04-build-pidgin-from-source/feed/ 2