C – Language History

The C programming language is a structure oriented programming language, developed at Bell Laboratories in 1972 by Dennis Ritchie
C programming language features were derived from an earlier language called “B” (Basic Combined Programming Language – BCPL)
C language was invented for implementing UNIX operating system
In 1978, Dennis Ritchie and Brian Kernighan published the first edition “The C Programming Language” and commonly known as K&R C
In 1983, the American National Standards Institute (ANSI) established a committee to provide a modern, comprehensive definition of C. The resulting definition, the ANSI standard, or “ANSI C”, was completed late 1988.
C programming language standards:
C89/C90 standard – First standardized specification for C language was developed by the American National Standards Institute in 1989. C89 and C90 standards refer to the same programming language.
C99 standard – Next revision was published in 1999 that introduced new features like advanced data types and other changes.
C11 and Embedded C language:
C11 standard adds new features to C programming language and library like type generic macros, anonymous structures, improved Unicode support, atomic operations, multi-threading and bounds-checked functions. It also makes some portions of the existing C99 library optional and improves compatibility with C++.
Embedded C includes features not available in C like fixed-point arithmetic, named address spaces, and basic I/O hardware addressing.
Operating systems, C compiler and all UNIX application programs are written in C language
It is also called as procedure oriented programming language. The C language is reliable, simple and easy to use. C has been coded in assembly language.
Features of C programming language:
Reliability
Portability
Flexibility
Interactivity
Modularity
Efficiency and Effectiveness
Uses of C programming language:


The C programming language is used for developing system applications that forms a major portion of operating systems such as Windows, UNIX and Linux. Below are some examples of C being used.
Database systems
Graphics packages
Word processors
Spreadsheets
Operating system development
Compilers and Assemblers
Network drivers
Interpreters
Which level is C language belonging to?



S.no


High Level


Middle Level


Low Level


1

High level languages provide almost everything that the programmer might need to do as already built into the language

Middle level languages don’t provide all the built-in functions found in high level languages, but provides all building blocks that we need to produce the result we want

Low level languages provides nothing other than access to the machines basic instruction set


2

Examples:

Java, Python

C, C++

Assembler

The C language is a structured language



S.no


Structure oriented


Object oriented


Non structure


1

In this type of language, large programs are divided into small programs called functions

In this type of language, programs are divided into objects

There is no specific structure for programming this language


2

Prime focus is on functions and procedures that operate on the data

Prime focus is in the data that is being operated and not on the functions or procedures

N/A


3

Data moves freely around the systems from one function to another

Data is hidden and cannot be accessed by external functions

N/A


4

Program structure follows “Top Down Approach”

Program structure follows “Bottom UP Approach”

N/A


5


Examples:


C, Pascal, ALGOL and Modula-2



C++, JAVA and C# (C sharp)


BASIC, COBOL, FORTRAN

Key points to remember in C language:
The C language is structured, middle level programming language developed by Dennis Ritchie
Operating system programs such as Windows, Unix, Linux are written in C language
C89/C90 and C99 are two standardized editions of C language
C has been written in assembly language
C language tutorial reference E-books & research papers:
[ANSI 89] American National Standards Institute., American National Standard for Information Programming Language C, X3 159-1989
[Kernighan 78] B. W. Kernighan and D. M. Ritchie, The C Programming Language, Prentice-Hall: Englewood Cliffs, NJ, 1978. Second edition, 1988.
[Thinking 90] C* Programming Guide, Thinking Machines Corp.: Cambridge Mass., 1990.