Hello Every One
Let's Talk About Linux :)

Hello! I am shams

GNU-Linux Is An Operating System!

We will talk about GNU later.

So What is an Operating system?

Windows, Mac, BSD and ... Are Operating Systems Too!

If I would describe it for my brother.

%% This is a comment in mermaid markup graph TD A(Human Need) B[Source Code] C{Compiler} D(Executable Program) E(Machine Languages) F(Programming Languages) A--Programmer-->B B-->C C-->D D-->E B-->F classDef startEnd fill:#fcc,stroke:#353,stroke-width:2px; class A,D,E startEnd;

%% This is a comment in mermaid markup graph TD A(Program) B[Operating System] C(Software) A-->B B-->C C-->B B-->A classDef startEnd fill:#fcc,stroke:#353,stroke-width:2px; class A,D,E startEnd;

Machine Language?!

Not Such A Big Deal!

    
        inc ram;
        //ram+=1;
        dec rbm;
        //rbm-=1;
        neg rcm;
        //rcm = -rcm;
        add ram, rbm;
        //ram = ram+rabm;
        mov ram, 5;
        //ram = 5;

It is really funny and intersting working with machine language cause you don't have if/for/... statements and also you have only primitive datatypes.

Let's Talk About

History

Of Linux

We had

Microsoft Windows
Apple Mac
UNIX

Windows in 80's was good.
Mac was better but also more expensive.
UNIX was the best but most expensive. for commerical apps.

The GNU Project

We Need An UNIX-LIKE and cheaper OS.

True Legend

Richard Stallman. Found the GNU At 1984.

GNU's Not UNIX

recursive defenition.
factorial recursive.

!5 = 5*!4

!4 = 4*!3

!3 = 3*!2

!2 = 2*!1

!1 = 1

Free UNIX-Like OS

Free Software

Freeware = Payment not required.
Free software = 4 freedoms.
Not Open Source

Freedom 1

The freedom to run the program for any purpose.

Freedom 2

The freedom to study how the program works, and change it to make it do what you wish.

Freedom 3

The freedom to redistribute and make copies so you can help your neighbour.

GPL

The freedom to improve the program, and release your improvements (and modified versions in general) to the public, so that the whole community benefits.