C Program Execution Process

Q.)   WHAT IS C?

C Language is a general purpose and structured programming language developed by 'Dennis Ritchie' at AT&T's Bell Laboratories in the 1972s in USA.

It is also called as 'Procedure oriented programming language.'

C is not specially designed for specific applications areas like COBOL (Common Business-Oriented Language) or FORTRAN (Formula Translation). It is well suited for business and scientific applications. It has some various features like control structures, looping statements, arrays, macros required for these applications.

The C language has following numerous features as:

·         Portability

·         Flexibility

·         Effectiveness and efficiency

·         Reliability

·         Interactivity

Execution of C Program:

C program executes in following 4 (four steps).

1.       Creating a Program :

An editor like notepad or wordpad is used to create a C program. This file contains a source code which consists of executable code. The file should be saved as '*.c' extension only.

2.       Compiling the Program :

The next step is to compile the program. The code is compiled by using compiler. Compiler converts executable code to binary code i.e. object code.

3.       Linking a Program to Library :

The object code of a program is linked with libraries that are needed for execution of a program. The linker is used to link the program with libraries. It creates a file with '*.exe' extension.

4.       Execution of Program :

The final executable file is then run by dos command prompt or by any other software.

History of C:

Year of Establishment	Language Name	Developed By
1960	ALGOL-60	Cambridge University
1963	CPL (Combined Programming Language)	Cambridge University
1967	BCPL (Basic Combined Programming Language)	Martin Richard at Cambridge University
1970	B	Ken Thompson at AT& T's Bell Laboratories.
1972	C	Dennis Ritchie at AT& T' Bell Laboratory.

The development of C was a cause of evolution of programming languages like Algol 60,

CPL (Combined Programming Language), BCPL (Basic Combined Programming Language) and B.

Algol-60 : (1963) :ALGOL is an acronym for Algorithmic Language. It was the first structured procedural programming language, developed in the late 1950s and once widely used in Europe. But it was too abstract and too general structured language.

·         CPL : (1963) :

CPL is an acronym for Combined Programming Language. It was developed at Cambridge University.

·         BCPL : (1967) :

BCPL is an acronym for Basic Combined Programming Language. It was developed by Martin Richards at Cambridge University in 1967. BCPL was not so powerful. So, it was failed.

·         B : (1970) :

B language was developed by Ken Thompson at AT& T Bell Laboratories in 1970. It was machine dependent. So, it leads to specific problems.

·         C : (1972) :

'C' Programming Language was developed by Dennis Ritchie at AT& T Bell Laboratories in 1972. This is general purpose, compiled, structured programming language. Dennis Ritchie studied the BCPL, then improved and named it as 'C' which is the second letter of BCPL