BRIEFLY DESCRIBE OF C

A Brief History of C C is a general-purpose language which has been closely associated with the UNIX operating system for which it was developed - since the system and most of the programs that run it are written in C. Many of the important ideas of C stem from the language BCPL, developed by Martin Richards. The influence of BCPL on C proceeded indirectly through the languageB, which was written by Ken Thompson in 1970 at Bell Labs, for the first UNIX system on a DEC PDP-7. BCPL and B are "type less" languages whereas C provides a variety of data types. In 1972 Dennis Ritchie at Bell Labs writes C and in 1978 the publication of The C Programming Language by Kernighan & Ritchie caused a revolution in the computing world. In 1983, the American National Standards Institute (ANSI) established a committee to provide a modern, comprehensive definition of C. The resulting definition, the ANSI standard, or "ANSI C", was completed late 1988. A Rough Guide to Programming Languages is available on-line for those of you that are interested.

Introduction to C Programming So you want to learn C? We hope to provide you with an easy step by step guide to programming in C. The course is split up into several sections, or lessons, which include C example programs for you to demonstrate what has been taught. Although the ordering of the sections does not have to be strictly followed, the sections become progressively more involved and assume background knowledge attained from previous sections. Good Luck! Before you start.... Please read the Introduction It is a long course and will take you quite a while to complete. If you use the Hotlist or Bookmark feature of your browser you will be able to return to the place where you left off at or to return to a particular section.

Introduction to the Course Objectives Having read this section you should be able to: Navigate successfully around the course Save the demonstration programs Navigation This is obviously a hypertext course and we must assumes that you know a little bit about how to use the client browser you are using to view this information. What you need for this course All sections have demonstration programs. If you want to learn how to program in C successfully then you must practice. You should run the demonstration programs so that you are sure of their constructs and how they work. They are not too difficult! To run the programs you will need access to a C compiler. This can be either on your browsing machine or on another machine you have access to. All demonstration programs are available as separate text files which can be saved on to your machine. When there is a program available you will see the following: [program] displayed after the demonstration program. Clicking on the highlighted text will display the demonstration program. Use your browser's Save As option to save the file. Experiment - change the programs; make them fail! It is just as important to know what an error message from your system looks like (and means) as it is to write good working programs. Most systems have file editors built into the operating system. If you don't like your local editor then use a word processing package but remember to save the files as ASCII text. (That is a link to our on-line Glossary of Computing Terms!) If there are any problems running the programs please let us know!

Overview to C Programming

Objectives

This section is designed to give you a general overview of the C programming language. Although much of this section will be expanded in later sections it gives you a taste of what is to come.

Why use C?

C has been used successfully for every type of programming problem imaginable from operating systems to spreadsheets to expert systems - and efficientcompilers are available for machines ranging in power from the Apple Macintosh to the Cray supercomputers. The largest measure of C's success seems to be based on purely practical considerations:

1. the portability of the compiler;
2. the standard library concept;
3. a powerful and varied repertoire of operators;
4. an elegant syntax;
5. ready access to the hardware when needed;
6. and the ease with which applications can be optimised by hand-coding isolated procedures

C is often called a "Middle Level" programming language. This is not a reflection on its lack of programming power but more a reflection on its capability to access the system's low level functions. Most high-level languages (e.g. Fortran) provides everything the programmer might want to do already built into the language. A low level language (e.g. assembler) provides nothing other than access to the machines basic instruction set. A middle level language, such as C, probably doesn't supply all the constructs found in high-languages - but it provides you with all the building blocks that you will need to produce the results you want!

Uses of C

C was initially used for system development work, in particular the programs that make-up the operating system. Why use C? Mainly because it produces code that runs nearly as fast as code written in assembly language. Some examples of the use of C might be:

1. Operating Systems
2. Language Compilers
3. Assemblers
4. Text Editors
5. Print Spoolers
6. Network Drivers
7. Modern Programs
8. Data Bases
9. Language Interpreters
10. Utilities

In recent years C has been used as a general-purpose language because of its popularity with programmers. It is not the world's easiest language to learn and you will certainly benefit if you are not learning C as your first programming language! C is trendy (I nearly said sexy) - many well established programmers are switching to C for all sorts of reasons, but mainly because of the portability that writing standard C programs can offer.

A Brief History of C

C is a general-purpose language which has been closely associated with the UNIX operating system for which it was developed - since the system and most of the programs that run it are written in C.

Many of the important ideas of C stem from the language BCPL, developed by Martin Richards. The influence of BCPL on C proceeded indirectly through the languageB, which was written by Ken Thompson in 1970 at Bell Labs, for the first UNIX system on a DEC PDP-7. BCPL and B are "type less" languages whereas C provides a variety of data types.

In 1972 Dennis Ritchie at Bell Labs writes C and in 1978 the publication of The C Programming Language by Kernighan & Ritchie caused a revolution in the computing world.

In 1983, the American National Standards Institute (ANSI) established a committee to provide a modern, comprehensive definition of C. The resulting definition, the ANSI standard, or "ANSI C", was completed late 1988.

A Rough Guide to Programming Languages is available on-line for those of you that are interested.

C for Personal Computers With regards to personal computers Microsoft C for IBM (or clones) PC's. and Borlands C are seen to be the two most commonly used systems. However, the latest version of Microsoft C is now considered to be the most powerful and efficient C compiler for personal computers. We hope we have now managed to convince you to continue with this online C course and hopefully in time become a confident C programmer.

REFERENCES BY-Built with Course Genie.