C Language Tutorial: Second lecture-Development history of C language

Previous lecture: Computer language overview

Martin Richards of the University of Cambridge in 1967 simplified the Combined Programming Language language, resulting in BCPL (Basic Combined programming Language) language.

In 1970, Ken Thompson of Bell Labs in the United States devised a new language based on the Bcpl language, a new language named after the first letter of "Bcpl", called "B language". Ken Thompson also wrote the world's first UNIX operating system in B language.

In 1973, D.m.ritchie of the Bell Laboratory in the United States, based on the B language, devised a new language, which was named after the second letter of "Bcpl", called "C language". Ken Thompson and D.m.ritchie have rewritten the UNIX operating system in C language.

During the development of the UNIX operating system, Ken Thompson and D.m.ritchie also transplanted the UNIX operating system to other types of computers, and the strong portability of C language was reflected. Machine languages and assembly language portability are very low, and C language portability is very good, C language program can be used in any architecture of the CPU, as long as the CPU of that architecture has the corresponding C language compiler and library, can be C language source code compiled, connected to the executable file. In the early days, C was mainly used in the development of UNIX operating system, then, C language because of its outstanding advantages, began to be applied to other operating system development, and quickly get widely used.

Before the advent of the C language, the world's operating systems were usually developed using assembly language. UNIX is the first operating system in the world that is not developed with assembly language.

After the C language has been widely used, there are many different C language versions in the world. There are a lot of incompatibilities between these versions, which has caused great inconvenience to C-language programmers. In order for the C language to develop well, in 1983, the National Standards Institute (ANSI) decided to set up the C Language Standards Committee to establish the C language standard.

In 1978, Brian Kernighan and Dennis Ritchie of Bell Labs in the United States published a book called "The C programming Language". This book is called "K&r", and for many years it has been regarded as the unofficial standard of C, and people call this version of C language "K&r C".

In 1989, the National Standards Institute issued a C language standard, the C language standard referred to as the "C89 standard", but also some abbreviation "ANSI C".

In 1990, the International Organization for Standardization (ISO) and IEC set the C89 standard as an international standard for C, the C language standard referred to as the "C90 standard", but this standard is identical to the "C89 standard".

The world famous, widely used C language standard also: C94 standard, C95 Standard, C99 Standard, C11 standard and so on.

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C Language Tutorial: Second lecture-Development history of C language