Unit 10

• Functions of user interface

  ...

  • Helps the user to use the computer system productively
  • Makes facilities accessible for the users
  • Common look and feel for applications
• OS user services

  ...

  • Loading and execution of program files
  • File commands
  • User I/O activity
  • Security and data integrity
• Features of file management system

  ...

  • Ability to treat files by a logical name
  • Handle physical manipulation of files and translate between logical and physical representations
  • Issue commands to the OS that stores, manipulate and retrieve files
  • Construct an effective file organization
• Interface designs

  CLI - command line interface

  GUI - graphical user interface
• CLI advantages/disadvantages

  CLI advantages:

  • More flexible and powerful
  • Faster for experienced users
  • Can combine commands

  CLI disadvantages:

  • Difficult to learn and use
• GUI advantages/disadvantages

  GUI advantages:

  • Easy to learn and use
  • Little training
  • Capable of multitasking

  GUI disadvantages:

  • Harder to implement
  • Requires lots of memory
• What is an operand?


  A value or expression that is used to perform an operation

  Keyword operand - an operand that has a specific name or symbol that carries a meaning to the system

  Positional operand - an operand that is identified by its position in a sequence or list