UNIXOverview of UNIX

Saturday, October 23, 2010

What is UNIX

• UNIX is a kind of Operating System which is the interface between hardware and application software

UNIXHardware

Application

Saturday, October 23, 2010

Functions of UNIX

• Support Programming

• Support many application

• Manage system resources

• Handle daily maintenance

Saturday, October 23, 2010

Features of UNIX• Multi-Tasking

• Multi-User

• Parallel Processing

• Pipe

• Shell

• High Security

• Reliable

• Network Oriented

• Easy to Transpant

Saturday, October 23, 2010

Component of UNIX

KernelFile System

ShellCommand

ApplicationShell

UNIX Kernel

Hardware

Users

Saturday, October 23, 2010

Some Conceptions• Terminal (Graphic & Text)

• Console

• User, Super User

• Group

• Process, Process id

• Foreground Process

• Background Process

• Device

• Raw Device

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Login and Logout

• Usually, we use telnet to login Unix System.

• Usually after logging in, the current directory is the HOME directory

Saturday, October 23, 2010

Using Unix Command

• Unix Commands are case sensitive.

• Command Syntax

• Command [-option] [arguments]

• Example:

• ls - l /home

• Help

• Man Command

Saturday, October 23, 2010

Using Unix Command

• Unix Commands are case sensitive.

• Command Syntax

• Command [-option] [arguments]

• Example:

• ls - l /home

• Help

• Man Command

Saturday, October 23, 2010

UNIX File System

Saturday, October 23, 2010

Four Types of UNIX File

1. Ordinary File (Plain Text and Binary)

2. Directory

3. Special File (Block Device File and Character Device File)

4. Symbolic Link

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UNIX Directory Structure

/bin

/

/lib /usr /dev/etc /tmp /user

/usr/bin usr/src /usr/man /usr/adm

Saturday, October 23, 2010

UNIX File Name

• Name of a FIle

• Max. Length is 255 character

• Case sensitive

• No Special Extension Name

• / Root

• . Current Directory

• .. Parent directory of current directory

• .filename hidden file

• ? Wildcard for a single letter

• * Wildcard for a any letter(s)

Saturday, October 23, 2010

UNIX File PermissionWhat is the out of Command: ls -l

Saturday, October 23, 2010

UNIX File Permission

• drwxr-xr-x 2 xinuosx staff 68 Oct 2 14:13 .

- ordinary filer readablew writablex executable

OwnerGroupOtherText

ownerGroup

others

Saturday, October 23, 2010