Overview of C Language

Why use C?

C has been used successfully for every type of programming problem imaginable from operating systems to spreadsheets to expert systems - and efficient compilers 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 optimized 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.

C Programs

A C program can vary from 3 lines to millions of lines and it should be written into one or more text files with extension ".c" for example hello.c. You can use "vi", "vim" or any other text editor to write your C program into a file.
This tutorial assumes that you know how to edit a text file and how to write source code inside a program file.