Initial development of language C has occurred in Bell Labs AT&T between 1969 and 1973 years. According to Ritchie, the most creative period has occurred in 1972. Language have named "C" because many of its features have been received from earlier language named "B" which it agree Ken Thompson, was the simplified version of programming language BCPL.

Origin C is close adhered to development of the operational system Unix which have been originally carried out in the assembler on PDP-7 Ritchie and Thompson, switching on some ideas from colleagues. Finally, they have decided to hold operational system in a front rack to PDP-11. Shortage B's of functionality to exploit some of features PDP-11, especially reporting to byte, has led to development of the early version of programming language C.



Original version PDP-11 of system Unix has been developed in the assembler. By 1973 language C became strong enough, that the most part of kernel Unix has been copied in C. It became one of the first kernels of the operational system which have been carried out in language of meeting.

K&R C

In 1978 Bryan Kernighan and Dennis Ritchie is have published the first release of programming language C. This book, known to programmers C as "K&R", was on sale for many years as the informal specification of language. The second release of book covers corresponded ANSI C to the standard later.

K&R Have entered some language features:

Standard library of input-output

long int type of data

unsigned int type of data

Compound operators of purpose

Even after the publication in 1989 of standard C still it is a lot of years K&R C still was considered as "the lowest general denominator" to which programmers C have limited themselves. At that time the maximum mobility was desirable, as many the senior compilers were still in use and consequently written K&R C the code can be legal Standard C.

In early versions of programming language C only functions which have returned value of nonintegral number, should be declared, if they are used before function definition. The function used without any previous declaration as it was supposed, has returned an integer if its value was used.