Transcript Welcome to Linux

Welcome to Linux
Chap#1
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Linux History
 GNU Project:
 Started at 1983 by Richard Stallman.
 Goal: creating a UNIX-like free operating system.
 His vision: software should be free from restrictions against copying
or modification in order to make better and efficient computer
programs.
 (Incidentally, the name GNU is a recursive acronym which actually
stands for 'GNU is Not Unix').
 By 1991 GNU created a lot of tools, but there was still no operating
system.
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 MINIX
was written from scratch by Andrew S. Tanenbaum, a USborn Dutch professor who wanted to teach his students
the inner workings of a real operating system.
 In 1991:
 Linux kernel is developed by Linus Torvalds.
 combining Linux kernel with the not-quite-complete GNU
system resulted in a complete free operating system called
linux.
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 Though a recent arrival, Linux is very well known as a child of UNIX
 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
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Linux is 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.
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Linux is a Free Software
 Free software is Software
 Used for any purpose
 Study to learn how it work and adapt to meet your
needs.
 Copy and redistribute.
 Distribute as a part of an improved software.
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LINUX System Components
 Kernel
Directly interacts with the hardware, provides common
services to program, and gives insulation from hardware
characteristics.
 Consists of file subsystem, process control subsystem,
device drivers and system calls interfaces.

 Shell
A program that takes commands typed in at the terminal
and translates them into instruction to internal system.
 Eg. Bourne shell (sh), C shell (csh), Korn shell (ksh), etc

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Linux Distributions
 Various organizations package the Linux kernel and system
programs as Linux distributions
 Such as :
SUSE, Fedora, Ubuntu, Red Hat, Debian, and Mandriva.
 The differences between distributions typically :
 is how the user installs the operating system.
 which graphical configuration tools are installed by default and
which tools are used to keep the system up-to-date.
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Common Linux features
 Multiuser:
 Multiple users can log in and working on the system at the same
time
 Multiuser systems divide computer resources among multiple users,
allowing for more efficient use of these resources.
 Multitasking:
 it is possible to have many programs running at the same time
 Graphical User Interface (X Window System)
 Hardware support
 you can configure support for almost every type of hardware that
can be connected to a computer
 Networking connectivity:
 Linux offers support for a variety of local area network boards,
modems, and serial devices.
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Common Linux features
 Network servers
 Providing networking services to the client computers on the LAN or
to the entire Internet is what Linux does best.
 Application support
 a wide range of freeware and shareware software is available for
Linux.
 Most of Linux is written in the C programming language.
When written in a portable style, C programs can be moved
from one platform (processor or CPU-based system) to another
by simply recompiling the code.
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Linux file system
• The Linux file system is the structure in which all
the information on your computer is stored.
• Files are organized within a hierarchy of
directories. Each directory can contain files, as well as
other directories.
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Directory
Directory Content
/
/bin
/boot
The root directory
/dev
Contains references to all the CPU peripheral hardware, which
are represented as files
/etc
/home
Contains administrative configuration files
/mnt
Contains Standard mount point for external file systems, e.g. a
CD-ROM or a digital camera.
/tmp
Temporary space for use by the system
/usr
Contains programs, libraries, documentation etc. for all userrelated programs.
/var
Contains storage for all variable files and temporary files created by
users, such as log files, the mail queue, the print spooler area, space for
temporary storage of files downloaded from the Internet, or to keep an
image of a CD before burning it.
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/sbin
Contains common Linux user commands such as ls, sort
Has the bootable Linux kernel and boot loader configuration files
Contains directories assigned to each user with a login account
Programs for use by the system and the system administrator.
Linux file system
/
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bin
boot
dev
etc
home
mnt
temp
user
var
sbin
bash
manal
nawal
mona
login.defs
passwd
group
skel