1. System Programming and administration
CS 308
Amal

2. Book

3. Course Information

4. Topics will covered (ان شاء الله)
Background
System Software and Machine architecture
Software tools
Overview of Compilers
Introduction to Assemblers
Loaders and its types
Linux Operating System
Linux commands
Linux Job & Process Management
Linux System Administration

5. System Programming and administration
Lecture 1
Background and Evolution of system programming

7. 1.1 Introduction Computer Systems Consist of Software consists of
Hardware
Software
Data
User
Software consists of
System Software
Application Software

8. 1.1 Introduction What is System? What is Programming?
System is the collection of various components ( e.g. College is a system).
What is Programming?
Art of designing and implementing the programs.

9. 1.1 Introduction What is Software ? Two types of software
Software is collection of many programs
Two types of software
System software
These programs assist general use of application programs.
Application software
These are the software developed for the specific goal

10. 1.1 Introduction System Software includes Operating systems
Command line interface
UNIX、DOS
Graphical User interface
MacOS 、Windows

11. 1.1 Introduction System Software includes Language Translators
Assembler
Compiler
Interpreter
Macro Processor:Macro is a single line abbreviation for group of instructions.

12. 1.1 Introduction Language Translation Flow Compile Linker
Program Coding
Compile
Problem Definition
Library
Linker
Object File
*.OBJ
Execution file
*.exe

13. 1.1 Introduction Service Programs Loader and Linker Text Editor
Debugger
Data Base Management Systems (DBMS)

14. 1.1 Introduction System Program
These are programs which are required for the effective execution of general user programs on computer system
System Programming
It is an art of designing and implementing system programs.

15. 1.1 Introduction What is system programming…?
System programming is the activity of programming system software.
Systems programming aims to produce software which provides services to the computer hardware .
It requires a greater degree of hardware awareness.

16. 1.2 Need Of System Software
The basic need of system software is to achieve the following goals
To achieve efficient performance of the system
To make effective execution of general user program
To make effective utilization of human resources
To make available new, better facilities

17. 1.3 System Software What is System Software？
System Software consists of a variety of programs that support the operation of a computer.
The programs implemented in either software and (or) firmware(ثابتة) that makes the computer hardware usable.
The software makes it possible for the users to focus on an application or other problem to be solved, without needing to know the details of how the machine works internally.

18. 1.4 System Software Concept
Users
Application Program
Debugger
Macro Processor
Text Editor
Utility Program (Library)
Complier
Assembler
Load and Linker OS
Memory Management
Process Management
Device Management
Information Management
Bare Machine (Computer)

19. 1.5 Evolution of Components Systems Programming
Reasons for the evolution (تطور)of system programs
To make computer better adapted to the need of users.
People wanted more assistance in the mechanics of preparing their program.

20. 1.6 Components will discussed
We will discuss about the evolution of following components of system programming
Assemblers
Compilers
Loaders
Linkers
Macros
Translated programs into machine language
resulting machine program loaded into memory and prepared for execution

21. 1.6.1 Assembler
Initially the users were compelled مجبر) (to write their program in machine code (a series of 0 and 1).
But the programmer found it difficult to write or read programs in machine code.
Now the users began to use some mnemonic (symbol) for each machine instruction, which they subsequently translate into machine language.

22. 1.6.1 Assembler
Such a mnemonic machine language is called assembly language.
Programs known as assembler were written to automate the translation of assembly language to machine code.
The input to the assembler is called the source program and the output is a machine language translation(object program).
Assembler
Source program
(assembly program)
Machine language
(Object program)

23. 1.6.2 Loaders
A loader is a system program that places programs into memory and prepares them for execution.
Once the assembler produces an object program, that program must be placed into memory and executed.
It is the purpose of loader to assure that object programs are placed in memory in an executable form.

24. 1.6.3 Macros First you should know what is subroutine?
A subroutine is a body of computer instruction designed to be used by other routines to accomplish a task.
There are two types of subroutine:
Open subroutine
Close subroutine

26. 1.6.3 Macros Open subroutine or Macros Closed subroutine
Whose code is inserted in the main program(flow continues).
Thus if the same open subroutine is called four times, it would appear in four different places in the calling program.
Closed subroutine
It can be stored outside the main routine, and control transfers to the subroutine.

27. 1.6.3 Need Of Macros
To relieve اعفاء منprogrammers of the need to repeat identical parts of their program operating system provide a macro processing facility, which permits the programmer to define an abbreviation for a part of his program and to use this abbreviation in his program.
The macro processor treats the identical parts of the program defined by the abbreviation as a macro definition and saves the definition.

28. 1.6.4 Compilers
As the user’s problems became more categorized into areas such as
scientific
Business
Statistical problems
Some high level languages were developed that allowed the user to express certain problems concisely and easily.
E.g. FORTRAN,COBOL,ALGOL…..

29. 1.6.4 Compilers
A compiler is a system program that accepts program written in HIGH level language and produces an object program.
Modern compilers must be able to provide the complex facilities that programmers are now demanding.
Compilers
High level language program
Machine language
(Object program)

30. Questions and answers