This is History of C programming Language.
C is closely associated with Unix Operating system
Development of Unix System
The PDP-11 version of Unix system was written in assembly language. Assembly languages are low-level programming languages that are specific to a particular computer architecture. They are hard to write and understand.
The developers of Unix Operating system (including Dennis Ritchie and Stephen C. Johnson) decided to rewrite the system in B language. However, B couldn’t suffice some of the features of PDP-11, which led to the development of C.
In 1972, the development of C started on the PDP-11 Unix system. A large part of Unix was then rewritten in C. By 1973, C was powerful enough to be used in Unix Kernel. Dennis Ritchie and Stephen C. Johnson made further changes to the language for several years to make it portable in Unix Operating system.
First Book on C Programming
In 1978, the first book of C programming, The C Programming Language, was published. The first edition of the book provided programmers informal specification of the language. Written by Brian Kernighan and Dennis Ritchie, this book is popular among C programmers as "K&R".
ANSI C
With the rapid growth of C language for several years, it was time for language to get it standardized.
C89. The first standard of C was published by American National Standards Institute (ANSI) in 1989. This version is commonly popular as C89.
C99. In late 1990’s, several new features like inline functions, several new data types and flexible array-members were added to the C standard. This is commonly known as C99.
C11. The C11 standard has new features like type generic macros, atomic operations, anonymous structures that doesn’t exist in C99.
All these three standards are also known by the name of ANSI C.
“Standard C programs are portable”. This means, the programs that follow ANSI C standard are portable among operating systems.
If you are new to programming, it’s advisable to follow the standard (ANSI C in case of C programming) that is accepted everywhere. It will help you learn the language the way it was intended.