UNIX LINUX Operating System

UNIX & LINUX
Operating System
Thanh-Hai DANG
Information Systems Dept -VNUH
Email:

“UNIX is user-friendly, but
UNIX also choose her friends very carefully”

Course statement
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Goal
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Usage, entire administration
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Not principles of OS.
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Perspective
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A friend of UNIX
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Linux in place of Windows in your mind
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Curious for the principles of OS (Go inside into it)
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Materials
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UNIX/LINUX curriculum of Asoc. Prof. Thuy. HQ,
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Linux Complete Command Reference by J.Purcell

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Securing and Optimizing Linux, Gerhard Mourani

Content
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Unix/Linux Chronology.
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File System
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Process Management
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User Management
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Networking with Unix
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Programable Filters
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Programming with Shell & C on Unix/Linux
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Some facilities

UNIX OS.
Some characteristics
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Written in a high level language (C)
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User interface simple but powerful enough
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Good file system
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Simple connection to peripherals
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Multi User and Multi Process
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Relative independence between data and hardware

Unix Chronology.
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Ken Thompson at Bell Labs (1969)
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Withdrew from MULTICS project
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Written in assembler for a GE-645 machine
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Dennis Ritchie
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First Release in 1971

Chronology (Cont.)
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1973, The Kernel rewritten in C (developed by Dennis
Ritchie)
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1975, Nearly all of OS.(v.6) rewritten in C (used in the
University of California in Berkeley)
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1979
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Seventh Edition
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Bourne shell included
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Kernel largely rewritten to be more portable to other
machine architectures

Chronology (Cont.)
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The 80’s
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/usr/group established in 1981
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X/OPEN (From many EU computer companies)
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IEEE from 1984 (enhancement of POSIX)
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1984 : the birth of 3 versions
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System V from AT&T ( System III from 82)
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4.2 BSD of Berkeley Uni, Base for many OS: Sun
Microsystems (SunOS), Digital (Ultrix)…
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XENIX of Microsoft for PC (Compatible with System
V)

Chronology (Cont.)
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At the end of 80’s, 2 organizations said hello
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UNIX International (UI)

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The agreement between AT&T and Sun : SVR4
(System V Release 4), The converged Edition of
System V and BSD
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Open Software Foundation (OSF)
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IBM, Digital, HP, Bull, Siemens, Apollo, Nixdorf

Chronology (Cont.)
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LINUX OS. came into our world (1991)
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Written by Linus Torvald at Univ of Helsinki
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For the Intel i386 family of processors
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Derived from MIMIX, one of the most successful
version of PC UNIX.

LINUX OS.
Some characteristics
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A typical OS for UNIX.
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GUI thru X-Windows
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Many network protocols supported
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Real-time supported

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Parallel computing and PC Cluster
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Multi languages

Free Software, Linux & Open Source
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1984 : Richard Stallman, The Father of GNU
(Gnu is Not Unix) found Free Software
Foundation (FSF)
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1989 : FSF yielded GPL (General Public
License)
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1991 :
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Linus Torvald announced and put all source code of
Linux 0.02 on the Internet.
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Follows GPL
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Included many GNU softwares (GNU/Linux)


Free Software, …(Cont.)
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1993 : Rémy Card invented ext2 file system for
Linux
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1994 : Linux ported to the other CPU not Intel:

Alpha, ARM, PowerPC, RISC, Sparc,
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1995 : Apache Group built Web server Apache
on UNIX/Linux
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1999 : Version 1.0 of GUI GNOME và KDE (3.x
now)
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2002 : Sun announced OpenOffice.org version
1.0

Distributions Linux
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Distribution = A collection of all or some programs
altogether around a Linux kernel which allows to install a
collaborative system, operating perfectly.
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Include one or more CD ROM
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Easily installed,
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May be other softwares not GPL or OpenSource
included

Distributions Linux
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RedHat (9.0),Mandrake (10.1), SuSE (9.1), RedHat
Enterprise Linux, Fedoral Core (6)
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Debian, Slackware, Knoppix, Caldera,

Live CD Linux
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Distro Linux on one CD
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GNU/Linux OS. Plus with necessary softwares
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Not affect the current status of PC, HD not required!
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Some typical distro
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Knoppix
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DemoLinux
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Mandows
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FreeSBIE

UNIX architect

Unix kernel architect

Shell system
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The command interpreter
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Show a prompt ($) and wait from keyboard
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Receive user’s commands

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Analyse commands: Name, option values and
parameters
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Use kernel to initialize a process
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Wait for process to finish
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Programming language also

Shell …(Cont.)
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Bourne shell (sh) ($): Steven Bourne, AT&T
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Korn Shell (ksh) : David G. Korn, AT&T
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C_Shell (csh) (%) : Bill Joy, UC Berkeley
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Tenex Shell (tcsh) (>) : extend of csh
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Bourne Again Shell (bash) (#) : Brian Fox, FSF (Linux)

Environment Variables
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Used by shell and some facilities (X11, mail, )
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$HOME: home directory of user
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$MAIL: mail name
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$PATH: List of path where commands are looked
for( separated by :)
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Initialize after login
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script: .bashrc, .bash_profile
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echo <Var_Name>

Working on UNIX
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Case sensitive
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Command ls: OK, Ls: NotOK
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User Interface
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Command:
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Hard to remember at the beginning (many options,
and parameter)
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For long run: deep understanding concepts,
working with system flexibly and efficiently
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Graphic
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GNOME, KDE / X-Window (XFree86)

Command common structure

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# <Command_Name> [<options>] [<Parameters>]
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<options>:
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Reduced : #date –d <string>
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Full: #date –date=<string>
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Eg. #ls –l test.cpp matrix.cpp
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Wild Card *, ?, [abc]
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#ls –l g*

Man Page
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Command man <command> :
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Show explanatory document for command
<command>
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Syntax + Options description + Examples
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<command> = command, library function, system file
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Note :
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Type ‘q’ to quit
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Command name exact
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Command man -k <keyword>