SEG3460 Tutorial 1

1
SEG3460 Tutorial 1

• Unix Introduction and
• Lab Practices

2
Introduction

• What is Unix?
• An operation system (OS), similar to Windows,
  MacOS X
• Widely use in both servers and workstations
• Why Unix?
• Stable, Feasible, Security, etc
• Greatest Software Ever Written!!http//www.inform
  ationweek.com/shared/printableArticle.jhtml?articl
  eID191901844
• Freely available clone/distributions are under
  rapid development (e.g. Linux FreeBSD)

3
Lab Practices

• Connecting to a Unix machine
• Using Xwin
• Using SSH
• What is happening? Similar to remote login
• Log-in
• User name and password
• Log-out
• Type exit or logout
• Or Ctrl-D means exit in Unix

4
Using Unix

• Shell a program that acts as a middleman between
  you and the UNIX OS
• A shell let users to
• Run programs
• Manage I/O of processes easily
• Similar to DOS, but not only maps commands to the
  corresponding executable programs
• Also includes a programming language shell
  script

5
Running a utility program

• Unix has a bundle of utility programs
• See the detail tutorial notes
• E.g.1 date
• E.g.2 man
• manual page
• For utility programs, append -s 1 when
  necessary
• For usual usage of utilities, we dont need to
  add flag to the command, E.g.
• man s 1 date
• date -u

6
Unix file system in brief

• A hierarchy of directories
• To locate a file in the system, a pathname is
  needed
• Command pwd
• print your current working directory
• Pathnames
• Absolute pathnames
• Starting from the root (/)
• Relative pathnames
• Starting from the current working directory

7
Managing Files on Unix (1)

• Creating a file
• touch ltnew filenamegt
• An interesting and yet an IMPORTANT questionIf
  you create/modify a file on a Unix machine, would
  it be seen on another Unix machine?
• Listing the content of a directory
• ls lta directorygt
• To view the content of a file
• cat lta filegt
• more lta filegt
• head lta filegt
• tail lta filegt
• My favorite less lta filegt

8
Managing Files on Unix (2)

• Moving/renaming a file
• mv ltoldFileNamegt ltnewFileNamegt
• mv ltaFileNamegt ltaDirectoryNamegt
• mv ltoldDirNamegt ltnewDirNamegt
• Making a directory
• Mkdir ltnewDirNamegt
• Change directory
• cd ltaDirNamegt

9
Managing Files on Unix (3)

• Copying a file
• cp ltoldFileNamegt ltnewFileNamegt
• Removing an empty directory
• rmdir ltaDirNamegt
• Delete a file
• rm ltaFileNamegt
• To remove a non-empty directory rm r
  ltaDirNamegt
• To remove a whole directory without
  prompt/bin/rm rf ltaDirNamegt

10
Editing a file

• emacs
• Adv has GUI, easy for beginners
• Dis relatively slow
• vim (i.e. Vi Improved)
• Adv fast for advance users
• Dis text-version is quite difficult to learn
• GUI version gvim, rgvim
• To learn, type vitutor in console
• pico
• Adv simple, easy to learn and use
• Dis no GUI
• Check their man page for detail usages