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 which $ ls -l $ which ls $ ls -a whereis $ ls -la $ whereis ls $ ls -l --sort=time locate $ ls -l --sort=size -r $ locate stdio.h cd $ locate iostream $ cd /usr/bin rpm pwd $ rpm -q bash $ pwd $ rpm -qa ~ $ rpm -qa | sort | less $ cd ~ find ~user $ find / | grep stdio.h $ cd ~VeerBahadur $ find /usr/include | grep stdio.h
Vi 2 modes Delete Input mode dd (delete a line) d10d (delete 10 lines) ESC to back to cmd mode d$ (delete till end of line) Command mode dG (delete till end of file) Cursor movement x (current char.) h (left), j (down), k (up), l (right) Paste ^f (page down) p (paste after) ^b (page up) P (paste before) ^ (first char.) Undo $ (last char.) u G (bottom page) Search :1 (goto first line) / Swtch to input mode Save/Quit a (append) :w (write) i (insert) :q (quit) o (insert line after :wq (write and quit) O (insert line before) :q! (give up changes)
Emacs $ emacs Paste Cursor movement ^y (yank) ^f (forward one char.) Undo ^b (backward one char.) ^/ ^a (begin of line) Load file ^e (end of line) ^x^f ^n (next line) Cancel ^p (prev. line) ^g ^v (page up) Save/Quit alt-v (page down) ^x^c (quit wiout saving) Deletion ^x^s (save) ^d (delete one char) ^x^w (write to a new file) alt-d (delete one word) ^k (delete line)
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 Linux Rpm –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 SinghDesignation : Asst. S/W Engineer(Trainee)Id No : VGT 153 T
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