General Commands in UNIX

1. Date:- Used to display Date and Time

$ date

$ date + % option

$ date + % D -> MM/DD/YY

$ date + % a -> sat

$ date + % A -> saturday

$ date + % h -> Dec

$ date + % m -> 12 (Month)

$ date + % y -> 09 (Year)

$ date + % d -> 01 (Day)

$ date + % T -> HH.MI.SS

$ date + % H -> HH (Hours)

$ date + % M -> Mi (Minutes)

$ date + % S -> SS (Seconds)

$ date + % D%T -> MM/DD/YY HH:Mi:SS

$ date + "% D%T" -> MM/DD/YY - HH:Mi:SS

Note: UNIX is space sensitive and case sensitive.

2. Man:- $ man

                              ( It gives help about Command)

ex:- $ man date

3. cal:- used to display calender

$ cal

$ cal 12 2009            (cal MM YYYY)

$ cal 2009                 (cal YYYY)

ex:- $ cal 9 1752

4. Who:- gives the List of users who are currently working in Operating System

$ who -> gives all users details

$ who am I -> gives only user information

$ who-H -> gives display with headings

ex:- $ who

 user     TTYNo     Time     IPAddress

User1   TTY01     10:00      *****

$ who-H

Name    Line       Time

User1   TTY01   10:00

5. Write:- used to send Messages to other users

ex:-   user1                                       |      User2

                          $ Write user2                         |      Message from user1

                           .......................                         |      ...................................

                           .......................                                 ...................................

                           (ctrl+d)                                                   (ctrl+d)

Note:- (ctrl+d -> quit the message)

Operating System

Introduction to Operating Systems:
It is a Layer of software
Interface between user and Hardware
Basic foundation for any application development

Classification of Operating Systems:
1. Character Based Operating Systems
2. GUI Based Operating Systems
3. Single User Operating Systems
4. Multi User Operating Systems

Operating System Services:
1. Interprets and Executes user commands
2. Manages the System Hardware
3. Allocate System Resources
4. Schedules processes
5. Facilitates Recovery
6. Maintains File System
7. Performs Administrative Functions
8. Performs House keeping Tasks

UNIX History:

• Developed by Ken Thompson in 1969
• Developed to transfer programs from GE645 to PDP-7 machine
• Single User for PDP-7 written in Assembly Language
• Moved to PDP-11 in 'B' Language in 1971
• Rewritten as a multiuser operating system in 'C' Language in 1973
• Licensed to universities in 1974
• Micro Computer version released in 1980
• Commercial version UNIX System III in 1981
• Popular Operating System available from micro to mainframe
• Available for scientific as well as commercial use
• Designed for effectiveness of

General System operation

Application Software development

System software development

Application Execution

Academic and Research work.

Application of UNIX:

• Word processing
• Financial Management
• Communication
• Graphics
• Software Developments
• Office Automation
• Academic and scientific environment
• Operating System research
• Prime Operating System for research work.

UNIX Flavours:

1. Sco UNIX
2. Hp UNIX
3. Solaris
4. AX UNIX
5. IREX UNIX
6. Linux - Redhat, Susu, Mandrek.

Features of UNIX:

• Multi User/ Multi Tasking/ Time Sharing system
• Modularity
• File Structure
• Input, Output Redirection and Pipes
• Consistent Peripheral Interface
• Security
• Communication and Networking
• Portablity
• Utilities
• Software development tools.

for Practising UNIX on ur System, You can download from the following site

http://www.ubuntu.com/getubuntu/download