Programming in C  © Kishori Mundargi; contributors: Myriam Grandchamp, Saraswathi Kaja, Sourav Chandra, Oscar Serrano Serrano et al. Source: PEOI


Chapter 1

History of C Programming language

Evolution of C programming language

C has often been termed as a "Pseudo high level language" or a "Middle level language" by many programmers. This is not because of its lack of programming power but because of its capability to access the system's low level functions. In fact C was invented specifically to implement UNIX. C instructions are compiled to assembly code, therefore, depending on the complexity of the code and on the compiler optimization capabilities, C code may run as fast as assemby.

Ken Thompson created the B language in 1969 from Martin Richard's BCPL (Basic Combined Programming Language). He used assembly language and B to produce the initial versions of the UNIX operating system. BCPL and B were typeless languages in which variables were simply words in memory. Dennis Ritchie of Bell Laboratories later converted B into C by retaining most of B's syntax in 1972 and wrote the first compiler. This was implemented on DEC's PDP 11 and it was first used as the system's language for rewriting the UNIX operating system. Later on, UNIX, its tools and C grew simultaneously. In 1978, Kernighan and Ritchie wrote a book entitled 'The C Programming Language' that became the language definition for almost a decade. Beginning in 1983, the ANSI X3J11 committee was asked to standardize the C language. The result was ANSI C, a standard which was adopted in 1988. It is not forced upon any programmer, but since it is so widely accepted, it would be economically unwise for any systems programmer or compiler writer not to conform to the standard.

Features of C Language