History of C

INTRODUCTION TO C:

·         C is a programming language developed at AT&T’s Bell laboratories of USA in 1972.

·         It was designed and written by a system programmer Dennis Ritchie.

HISTORY OF C:

The following flow diagram shows the evolution of C –

·         The root of all modern languages is ALGOL, introduced in 1960s. It was the first computer language to use block structure.

·         In 1967, Martin Richards developed a language called BCPL (Basic Combined Programming Language) mainly for writing system software.

·         In the year 1970, using the concepts of BCPL, Ken Thompson developed a language called B. It was used to create earlier versions of UNIX operating System at Bell Laboratories.

o   Both B and BCPL were typeless system programming languages

·         C was evolved from ALGOL, BCPL and B by Dennis Ritchie at the Bell Laboratories in 1972.

o   C added the concept of data types

o   Since C was developed along with the UNIX operating system, it is strongly associated with UNIX.

·         The language became more popular after the publication of the book “The C Programming Language” by Brian Kernighan and Dennis Ritchie in 1978. The book was so popular that the language came to be known as”K & R C”.

·         Later on it was made an American Standard (ANSI C) and then International (ISO).

·         C99 is a standardized version of C which was done in 1999; so the name C99.

C language became popular because of the following reasons –

§  C is a robust language with a rich set of built-in functions and operators.

§  The C compiler combines the capabilities of an assembly language with the features of a High Level Language and therefore it is well suited for writing both system software and business packages.

§  C language is highly Portable – This means that C programs written for one computer can be run on another with little or no modification.

§  C language is well suited for Structured programming, thus user needs to think a program in terms of function modules or blocks. – This modular structure makes program debugging, testing and maintenance easier.

§  A C program is basically a collection of functions that are supported by the C library. We can continuously add our own functions to C library.