Introduction to C

History of C

C was developed by a system programmer Dennis Ritchie in 1972, at American Telegraph & Telecommunication (AT & T) Laboratories in New Jersey USA. It was written originally for programming under UNIX operating system. C was developed from BCPL (Basic Combined Programming Language) which was improved and renamed as B. B was developed in 1960’s at Cambridge University.

Table Of Hierarchy Of  Different Languages

C is actually a symbolic instruction code, a set of commands that perform actions on a computer. The C language is often referred as middle-level language because we can write high as well as low programs through C. Languages prior to C are FORTRAN (Formula Translation), COBOL ( Common Business Oriented Language), BASIC (Beginners All Purpose Symbolic Instruction Code) and Pascal. Languages after C are C++, Java, C# etc. C permits very close interaction with the inner working of the computer.

What is C

C is a programming language used to write a program. Programs are the set of instructions given by a programmer to the computer in high-level language. C uses a compiler to translate the high-level program into machine code before executing any instructions. Compiler is itself a computer program. Other translators are Interpreter and Assembler. The original high-level program is called the source program (C.) and the resulting machine language program is called the object program (.obj).

Merits of C

1) C is a general purpose programming language: You can generate games, business software, utilities, mathematical models, word processors, spreadsheets and other kinds of software.

2) C is structured programming language: It uses structured statements such as while, for loops in place of goto statements which cause bugs (error) in the program.

3) System independence: C does not require any services from the operating system, it runs independently. C can run on any operating system.

4) High efficiency: C language data and control mechanisms are well matched to most small computers and microcomputers.

5) System programming: C is used for system programming i.e. writing operating systems. The UNIX operating system is also rewritten from C.

Facts about C

• C was invented to write an operating system called UNIX.
• C is a successor of B language which was introduced around the early 1970s.
• The language was formalised in 1988 by the American National Standard Institute (ANSI).
• The UNIX OS was totally written in C.
• Today C is the most widely used and popular System Programming Language.
• Most of the state-of-the-art software have been implemented using C.
• Today’s most popular Linux OS and RDBMS MySQL have been written in C.

Why use C

C was initially used for system development work, particularly the programs that make-up the operating system. C was adopted as a system development language because it produces code that runs nearly as fast as the code written in assembly language. Some examples of the use of C might be −

• Operating Systems
• Language Compilers
• Assemblers
• Text Editors
• Print Spoolers
• Network Drivers
• Modern Programs
• Databases
• Language Interpreters
• Utilities