1. Chapter 14 The User View of Operating Systems
The Architecture of Computer Hardware and Systems Software: An Information Technology Approach
3rd Edition, Irv Englander
John Wiley and Sons 2003
Wilson Wong, Bentley College
Linda Senne, Bentley College

2. User Interface Help the user use the computer system productively
Provide consistent user interface services to application programs to lower learning curves and increase productivity
Choice of user interface depends on the kind of user
Writing programs vs. running applications
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User View of Operating Systems

3. User Functions Program execution File commands
Mount and unmount devices
Printer spooling
Security
Inter-user communication
System Status
Program Services
DCOM, CORBA, Remote Procedure Call (RPC)
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User View of Operating Systems

4. Interface Design CLI - Command Line Interface Batch System Commands
Menu-Driven Interfaces
GUI - Graphical User Interface
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5. Command Line Interface
command <operand1> <operand2> …
<switch1> <switch2> …
Operands
keyword (switches) and/or positional
Advantages
More flexible and powerful
Faster for experienced users
Can combine commands
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User View of Operating Systems

6. Command Line Interfaces
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7. Command Languages
Provide a mechanism to combine sequences of commands together. These pseudo-programs are known as scripts or batch files.
Startup files – OS configuration, user preferences
Features of Command Languages
Can accept input from the user and can output messages to I/O devices
Provide ability to create and manipulate variables
Include the ability to branch and loop
Ability to specify arguments to the program command and to transfer those arguments to variables within the program
Provide error detection and recovery
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User View of Operating Systems

8. DOS Batch File
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9. UNIX Shell Script
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10. Menu-Driven Interface
No need to memorize commands
All available commands are listed
Menus can be nested
Low data requirements
Still used in many ATM and Point-of-Sale systems
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11. Menu Driven Interface
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12. Windows Interfaces Also known as Graphical User Interfaces (GUIs)
Mouse-driven and icon-based
Windows
Are allocated to the use of a particular program or process
Contain a title bar, menu bar, and widgets
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User View of Operating Systems

13. GUI Interface – Windows XP
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14. GUI Interface – Linux KDE
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User View of Operating Systems

15. GUI Interface - MacIntosh
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User View of Operating Systems

16. GUI vs. CLI GUI Advantages Disadvantages CLI Advantages Disadvantages
Easy to learn and use
Little training
Amenable to multi-tasking
Disadvantages
Harder to implement
More HW/SW requirements
Requires lots of memory
SW is complex and difficult to write
CLI
Advantages
More flexible and powerful
Faster for experienced users
Can combine commands
Disadvantages
More difficult to learn and use
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User View of Operating Systems

17. X-Windows
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18. Duocentric Interface
Focus on the document rather than the application being executed
Expand role of OS by moving capabilities from the application to system services
Example: click on document to run program
Effort to assure that every application program responds in similar ways to user actions.
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User View of Operating Systems

19. Copyright 2003 John Wiley & Sons
All rights reserved. Reproduction or translation of this work beyond that permitted in Section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Request for further information should be addressed to the permissions Department, John Wiley & Songs, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The Publisher assumes no responsibility for errors, omissions, or damages caused by the use of these programs or from the use of the information contained herein.”
Chapter 14
User View of Operating Systems