Unix Survival Guide

1
Unix Survival Guide
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What is Unix ?

• Very popular OS. (Solaris, HP/UX, Ultrix, Linux,
  FreeBSD, etc.)
• Being used in many medium-end/high-end servers.
• Very stable, flexible, portable.

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Why do you need to care ?

• Good question! It is Windows world anyway.
• WRONG!
• A lot of servers are Unix-based.
• Unix is older than Windows but yet it still has
  the old basic concepts.
• Unix is considered to be cleaner than Windows
  in term of coding.
• Unix is still more secured than Windows.
• Most of network devices are Unix-based (e.g.
  routers, caches, mail servers, security servers).
• You can find a job with good pay with Unix.

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Unix History

• Born in 1969 as a child of project called
  Multrics (by Bell Labs, GE, and MIT).
• Its famous parents Ken Thompson and Dennis
  Ritchie.
• Its famous sibling (and supporter) C language
  (by Brian Kennigan and Dennis Ritchie).
• First machine DECs PDP-7.
• First game on Unix space travel.
• Famous game on early Unix rogue.

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Unix Features

• Why is it so popular ?
• Multitasking.
• Multiuser.
• Portability.
• Network applications.

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Basic Skills for this Class

• Basic Unix operations login, logout, directory
• Basic Unix commands man, ls, cd, pwd, rm, mv,
  cat, more
• Editing commands pico, vi
• Assembler / Debugger as, ld, gcc, gdb
• Which computer you can use ?
• Remote login (using telnet or secure shell).
• cpu200, zeus, and athena.

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Basic Unix Operations

• Start using the system login
• login natawut
• Password
• Last login Mon Aug 12 223702 from
  zeus.cp.eng.chula
• Quitting from the system logout
• logout
• ALWAYS LOGOUT !!!
• Can use exit or CTRL-D.

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Editing Keys

• When entering a command at the shell prompt
• erase one character ctrl-H / backspace
• erase the whole line ctrl-U
• stop execution ctrl-C
• pause output to the screen ctrl-S
• resume after a pause ctrl-Q

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Directory Structure

• All files are organized in (sub)directory
  (folders).
• hierarchy current directory, parent directory,
  root directory
• path reference absolute, relative

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Basic Unix Commands

• Getting help man (manual)
• man ls
• man man
• format man ltcommandgt

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Basic Unix Commands (cont)

• Listing all the files ls
• ls
• Admin Class bin
  public_html
• options ls -l, ls -a, ls -al, ls ltdirectorygt
• ls l Class
• ls al ..
• format ls -laCFR ltdirectorygt

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Basic Unix Commands (cont)

• Understand permissions
• ls -l
• total 168
• drwxr-xr-x 3 natawut faculty 4096 Aug 5
  1624 Class
• drwxr-xr-x 2 natawut faculty 4096 Jul 10
  0025 Images
• drwxr-xr-x 2 natawut faculty 4096 Jul 10
  0025 Library
• drwxr-xr-x 8 natawut faculty 4096 Jan 26
  2002 Old
• drwxr-xr-x 2 natawut faculty 4096 Aug 5
  1609 Publications
• drwxr-xr-x 2 natawut faculty 4096 Aug 1
  0104 Templates
• -rw-r--r-- 1 natawut faculty 4800 Aug 1
  0105 class.html
• -rw-r--r-- 1 natawut faculty 4551 Aug 1
  0117 contact.html
• -rw-r--r-- 1 natawut faculty 5817 Aug 1
  0121 home.html
• -rw-r--r-- 1 natawut faculty 3343 Feb 19
  1715 index.html
• ...

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Basic Unix Commands (cont)

• Finding out where I am pwd (print working
  directory)
• pwd
• /home/natawut
• Walking around cd (changing directory)
• cd Admin
• pwd
• /home/natawut/Admin

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Basic Unix Commands (cont)

• change to parent directory, root directory.
• pwd
• /home/natawut/Admin
• cd ..
• pwd
• /home/natawut
• cd /
• pwd
• /
• cd
• pwd
• /home/natawut

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Basic Unix Commands (cont)

• change to absolute path, relative path.
• pwd
• /home/natawut
• cd public_html/Class
• pwd
• /home/natawut/public_html/Class
• cd /usr
• pwd
• /usr
• cd
• pwd
• /home/natawut
• cd ../../usr
• pwd
• /usr

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Basic Unix Commands (cont)

• Deleting stuffs rm (remove)
• rm hw1.asm
• Changing a files name / Moving things around mv
  (move)
• mv hw1.asm h1.abc
• mv h1.abc Class
• mv h1.abc Class/hw1.txt

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Basic Unix Commands (cont)

• Displaying files content cat
• cat hw1.asm
• A better version than cat more
• more hw1.asm

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Editing Files in Unix

• Several editing programs pico, vi, emacs
• Simple editor pico
• Available only on cpu200.
• Similar to Notepad program on Windows.
• For advance users vi and emacs

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References

• man pages.
• Grace Todino et. al., Learning the UNIX Operating
  System, OReillyAssociates, Inc.
• Other Unix books.
• Links in my homepage.
• http//www.cp.eng.chula.ac.th/natawut