Linux lec 1

Historical Introduction to open source
and Linux



Lecturer : George Ajam
College of IT/ Network Dept.


Contents
What is Linux
Where did it come from?
Open Source Software
How do you get it?
Why is it significant?
Logging in and Rules


What is Linux
A fully-networked 32/64-Bit Unix-like Operating System
Unix Tools Like grep (explained later)
Compilers Like C, C++, Fortran, Smalltalk, Ada
Network Tools Like telnet, ftp, ping, traceroute
Multi-user, Multitasking, Multiprocessor
Has the X Windows GUI
Coexists with other Operating Systems
Runs on multiple platforms
Includes the Source Code

Where did it come from?
Linus Torvalds created it
with assistance from programmers around the world
first posted on Internet in 1991
Linux 1.0 in 1994; 2.2 in 1999
Today used on 7-10 million computers
with 1000’s of programmers working to enhance it
Open Source Software
When programmers on the Internet can read, redistribute, and modify the source for a piece of software, it evolves
People improve it, people adapt it, people fix bugs. And this can happen at a speed that, compared to conventional software development, seems astonishing

How do you get it?
Download it from the Internet
From a “Distribution” (e.g. Ubuntu)
Linux kernel
X Windows system and GUI
Web, e-mail, FTP servers
Installation & configuration support
3rd party apps
Hardware support
Why is it significant?
Growing popularity
Powerful
Runs on multiple hardware platforms
Users like its speed and stability
No requirement for latest hardware
It’s “free”
Licensed under GPL
Vendors are distributors who package Linux



Logging In
Connect to the Linux system using telnet:
vt100, vt220, vt320
ansi
tty
X-windows
Able to login more than once with same user
No ‘MW’ problems!
Logging In
Before you can use it you must login by specifying your account and password:

Rule Number 1
Do not login as root unless you have to
root is the system superuser (the “maint” of Linux but more “dangerous”)
Normal protection mechanisms can be overridden
Careless use can cause damage
Has access to everything by default
root is the only user defined when you install
First thing is to change root’s password
The second job is to define “normal” users for everyday use.