Linux History & Features

Roadmap

What is Unix? What is Linux? Which Linux Distribution is better? Linux : Advantages & Disadvantages Basic Commands Vi and Emacs Available Software Web Server

What is Unix?

A multi-task and multi-user Operating System Developed in 1969 at AT&T’s Bell Labs by

Ken Thompson (Unix) Dennis Ritchie (C) Douglas Mcllroy

Some other variants: System V, Solaris, SCO Unix, SunOS, 4.4BSD, FreeBSD, NetBSD, OpenBSD, BSDI

Before Linux: UNIX

Many difficulties in Multics development 1969

AT&T pulled out of Multics Ken Thompson

A simplified version of Multics UNIX Dennis Ritchie

Rewrite the UNIX in C

AT&T cannot sell the UNIX UNIX is the first free Operating System

What is Linux?

A clone of Unix Developed in 25 August 1991 by Linus Torvalds, a

Finish graduate student Inspired by and replacement of Minix Linus' Minix became Linux Consist of

Linux Kernel GNU (GNU is Not Unix) Software Software Package management Others

What is Linux?

Originally developed for 32-bit x86-based PC

Ported to other architectures, eg. Alpha, VAX, PowerPC,

IBM S/390, MIPS, IA-64 PS2, TiVo, cellphones,

watches, Nokia N810, NDS, routers, NAS, GPS, …

Which Linux Distribution is better? > 300 Linux Distributions

Slackware (one of the oldest, simple and stable distro.) Redhat

RHEL (commercially support) Fedora (free)

CentOS (free RHEL, based in England) SuSe ( based in German) Gentoo (Source code based) Debian (one of the few called GNU/Linux) Ubuntu (based in South Africa) Knoppix (first LiveCD distro.) …

Advantages of Linux

Linux is free: Price is zero. Unlimited copies permitted. Read and change source code.

Manuals are on-line. Common in scientific circles. Text interface is good for batch processing

and management.

Disadvantages of Linux

Text interface is not as user-friendly as Windows. But, has StarOffice software which is looks much

like Windows. Less commercial software available.

But, more scientific software available. More difficult to set up.

But, once set up, easy to manage.

Basic Commands

ls $ ls -l $ ls -a $ ls -la $ ls -l --sort=time $ ls -l --sort=size -r

cd $ cd /usr/bin

pwd $ pwd

~ $ cd ~

~user $ cd ~VeerBahadur

which $ which ls

whereis $ whereis ls

locate $ locate stdio.h $ locate iostream

rpm $ rpm -q bash $ rpm -qa $ rpm -qa | sort | less

find $ find / | grep stdio.h $ find /usr/include | grep stdio.h

Vi

2 modes Input mode

ESC to back to cmd mode Command mode

Cursor movement h (left), j (down), k (up), l (right) ^f (page down) ^b (page up) ^ (first char.) $ (last char.) G (bottom page) :1 (goto first line)

Swtch to input mode a (append) i (insert) o (insert line after O (insert line before)

Delete dd (delete a line) d10d (delete 10 lines) d$ (delete till end of line) dG (delete till end of file) x (current char.)

Paste p (paste after) P (paste before)

Undo u

Search /

Save/Quit :w (write) :q (quit) :wq (write and quit) :q! (give up changes)

Emacs

$ emacs Cursor movement

^f (forward one char.) ^b (backward one char.) ^a (begin of line) ^e (end of line) ^n (next line) ^p (prev. line) ^v (page up) alt-v (page down)

Deletion ^d (delete one char) alt-d (delete one word) ^k (delete line)

Paste ^y (yank)

Undo ^/

Load file ^x^f

Cancel ^g

Save/Quit ^x^c (quit wiout saving) ^x^s (save) ^x^w (write to a new file)

Available Software

Compilers: G77 (FORTRAN 77) Gcc ( C ) g++ (C++)

Text editors Emacs

Typesetting Troff, TeX

Graphing Gnuplot

Available Software

StarOffice provides a Windows-like environment: Word processor Spreadsheet Overhead slide designer

Can load and save existing files created on a Windows computer.

User Management

Simple way to add user is adduser command Passwd will allow to change the passwd Ofcourse there are host of GUI tools for all

these user management Group all common user to single group Be carefull while editing /etc/passwd

/etc/shadow passwd file may also exist.

User Management

Common files to look at /etc/passwd /etc/group /etc/shadow /etc/samba

Web server on Linux

Apache server is mostly available on LinuxRpm –q –all | grep apache to check

This can be started via init services /etc/rc.d/init.d/httpd start

Configuration files are at /etc/httpd/conf/ Normally log files at /var/log/httpd

Lost Root Passwd

If you have Lilo installed, type LILI: linux init 1 Change the root passwd, reboot aga

If you have installed grub Type ‘e’ to go to edit mode, add init 1

argument at the end Boot with knoppix or single floppy linux

Mount the disk and change root passwd Reboot !!

GNU/Linux & You (Computer Engineer) Ok! ! !

Windows is more popular 90% of Desktop computers run Windows

But! The 90% contains children, officers, … How many CEs do use the Windows? How many professional applications

(supercomputing) do use the Linux?

GNU/Linux & CEs

Linux is NOT for dummies Linux is for CEs

Linux does NOT hide anything In details boot message Kernel messages No registry All config files are text files

Using Linux needs computer knowledge You have the knowledge

GNU/Linux & You

If you target PhD in Computer Science You must learn Linux Most tools, simulators, protocols, … are

implemented & tested in Linux If you target Engineering in Iran

Linux Administrator Linux Application developer Embedded Linux Developer

Presented By : Beer Bahadur Singh

Designation : Asst. S/W Engineer(Trainee)

Id No : VGT 153 T