Linux Basics WeeSan Lee

Linux Basics

• WeeSan Lee

Roadmap

• What is Unix?

• What is Linux?

• Which Linux Distribution is better?

• Fish vs. Fishing

• Basic Commands

• Vi and Emacs

• Q&A

• References

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 (Pipes - Do one thing, do it well)

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

What is Linux?

• A clone of Unix

• Developed in 1991 by Linus Torvalds, a Finnish 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.)
• …

Which Linux Distribution is better?

Which Linux Distribution is better?

• Ask yourself these questions (from LAH)

• Is it going to be around in 5 yrs?
• Is it giong to stay on top of the latest security patches?
• Is it going to release updated software promptly?
• If I have problems, will the vendor talk to me?

• Personally, I use Slackware

• But, we will use CentOS (possibly along with Slackware :)

Fish vs. Fishing

• Manpage

• $ man ls
• $ man 2 mkdir
• $ man man
• $ man -k mkdir

• Manpage sections (LAH Table 1.2 @ page 12)

• 1 User-level cmds and apps
• /bin/mkdir
• 2 System calls
• int mkdir(const char *, …);
• 3 Library calls
• int printf(const char *, …);

Fish vs. Fishing (cont)

• Google

• linux package management -rpm
• “linux package management” -rpm
• linux OR windows
• rpm site:redhat.com
• linux faq filetype:pdf

• Info

• Text-base, menu-based help from GNU
• ?, h, u, t, ^N, ^P, Enter
• $ info info

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 ~weesan

• What will “cd ~/weesan” do?

Basic Commands (cont)

• echo

• $ echo “Hello World”
• $ echo -n “Hello World”

• cat

• $ cat /etc/motd
• $ cat /proc/cpuinfo

• cp

• $ cp foo bar
• $ cp -a foo bar

• mv

• $ mv foo bar

• mkdir

• $ mkdir foo

Basic Commands (cont)

• tar

• $ tar cvfp lab1.tar lab1

• gzip

• $ gzip -9 lab1.tar

• untar & ungzip

• $ gzip -cd lab1.tar.gz | tar xvf –
• $ tar xvfz lab1.tar.gz

• touch

• $ touch foo
• $ cat /dev/null > foo

Basic Commands (cont)

• Disk usage

• $ df -h /

• File space usage

• $ du -sxh ~/

• Advance stuff 

• $ ssh eon who
• $ ssh eon ‘cd .html ; tar cvfp - cs183 | gzip -9c’ | tar xvfpz -
• $ ssh kilo-1 ‘tar cvfp - /extra/weesan’ | tar xvfp - -C /

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)

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)

Q&A

References

• LAH

• Ch 1: Where to Start

• Unix history

• http://en.wikipedia.org/wiki/Unix
• http://upload.wikimedia.org/wikipedia/commons/7/77/Unix_history-simple.svg

• Linus Torvalds

• http://en.wikipedia.org/wiki/Linus_Torvalds

• Linux Kernel

• http://www.kernel.org/

References

• GNU (Gnu’s Not Unix)

• http://www.gnu.org/

• Linux Distribution

• http://en.wikipedia.org/wiki/Linux_distribution
• http://en.wikipedia.org/wiki/List_of_Linux_distributions

• PS2: Computational Cluster

• http://arrakis.ncsa.uiuc.edu/ps2/cluster.php

• Linux Gadgets

• http://linuxdevices.com/articles/AT4936596231.html

• TiVo

• http://dynamic.tivo.com/linux/linux.asp

References

• Nintendo DS Lite

• http://www.nintendo.com/ds/

• Nokia N810

• http://www.nokia.com/
• http://www.engadget.com/2007/10/17/nokia-n810-gets-official/

• Linux Distribution

• http://en.wikipedia.org/wiki/Linux_distribution
• GNU/Linux Distro Timeline: http://futurist.se/gldt/
• http://www.distrowatch.com/
• http://www.linux.org/dist/

• Google Advance Search

• http://www.google.com/intl/en/help/refinesearch.html