A friendly Introduction to Computer Security

computer_securityIf you have spent some time working with(or building) software that communicates on the network ,then you have probably come across terms like SSL, MD5, SHA ,HTTPS ,STARTLS, TLS etc.Ever wondered what all that gibberish means ? Simply put ,these are technologies that aim to make your online activity secure.Secure ? How?Well Security of a computer system can be thought of from a good number of perspectives but I will just cover the most popular three :

(1) Confidentiality : Making sure that nobody other than the intended recipient sees the data you send online.Continue reading

A friendly introduction to XMPP

xmpp_iconXMPP stands for eXtensible Messaging and Presence Protocol.It is an open standard protocol that is used to build real time applications.Example applications are Instant Messaging Apps ,White-boarding applications,real time gaming applications and many more.The protocol uses XML as a means to exchange information.In short XMPP allows you to send chunks of XML data from one node to another in real time .In this tutorial we lay down the conceptual concepts needed to make your XMPP journey as smooth as possible.Continue reading

How to install ejabberd with os specific package(.deb)

ejabberd-xmpp-logoIn a previous tutorial we showed how to install ejabberd from source code wich is rather involved process but also flexible.In this tutorial we show a less complicated way to get your ejabberd instance up and running.

This will work for you only if processOne or someone has already provided packages for the operating system flavour you are using.The ProcessOne installation page states that they provide both RPM and DEB packages respectively for RedHat and Debian based systems.Continue reading

How to Install ejabberd from source code on linux ubuntu

ejabberd-xmpp-logoejabberd is an XMPP application server powering a good number of instant messaging applications out there.In this post we are going to learn how to install it on a unix based operating system.I will cover ubuntu14.04,but the steps should work on all systems with little or no modifications.

While installing any piece of software ,it is always a good idea to check what the official documentation has to say ,processOne has a good page covering how to install ejabberd.In this tutorial we are going to install from the source code as I find this option most flexible(it is also the most complicated).Continue reading

ns3 beginner tutorial

I was looking for good beginner tutes for ns3 (besides the official doc ofcourse) and stumbled on this cool link:

Introduction to NS-3

It is organized in slides and you might want to use your arrow keys to navigate through’em.

Hope this helps

How to Build Software from the sources

Building software form sources is the process of compiling the source code so you can get the final executable file your users can run and enjoy .In this series of tutorials we attempt to cover how it is done form a practical point of view .Along the way we show the tools ,tips and tricks one uses to get the job done.Also we make sure that the code you compile works both on Linux and Windows.Continue reading

How to use to makefiles –Compiling Hello World

When managing the build process of your source files,compiling ,recompiling and keeping track of which object files need to be rebuilt can bee a tedious task. Make tools were created to ease that build process.All you have to do is tell them the structure of your project and the dependency relationship between your files and you are done! Give the command and your project is built(rebuilt) and all the dirty details are handled for you.Continue reading

Compiling C/C++ programs–Object Files

Object files are generated in the process of compilation [Link].They contain a set of machine code instructions (made of lots and lots of 0s and 1s),and computers understand them pretty well.Once you have object files for your C/C++ program ,you are one step away from the final executable file ,which is the whole purpose ofContinue reading

Compiling C/C++ Programs from Command Prompt/Terminal

Building Software from the sources is a process that combines compiling and linking the source code.The result of the process is a binary executable that the end user can run on his/her target machine.In this article ,we will be building a simple hello world program that is organized into multiple files to expose important details.Our program will be built both for Linux and Windows and we will be working on the terminal/command prompt.Continue reading