Language C (1) By Randa

Generalities: Types of programmes: -operating system ”système d’exploitation” like Windows XP, Windows 98, Unix, Linux… -programmes of application. Different levels of languages: -machine’s language written just by 0 and 1. -assembly language (use symbols). -high level languages (like C, JAVA, C++,…)

Generalities: Bases of programming: -algorithm: a logical sequence of steps for solving a problem, often written out as a flow chart, that can be translated into a computer. -program: translation of an algorithm into a programming language that tells a computer to perform a task.

Generalities: -programming language: a unique vocabulary and set of rules for writing computer programs.

Historic: 1970 : Development of language C by Dennis Ritchie in Laboratories Bell of AT&T : Publication of « The C programming language» by Kernighan & Ritchie, definitive specification of language C : Production of standard ANSI (« American National Standards Institute ») C, standard version of language C : Development of C++ by AT&T : appearance of the second edition of « The C programming language».

Characteristics of language C: It is a versatile language which allow the development of operating systems, programs of application and management. Advantages: *universal: not specific for one type of applications. *compact: based on a limited number of functions and operators used to write simple, efficient expressions.

*modern: it is a structured, recursive …language. *rapid and close to the machine: it uses expressions and operators which are so close to the machine language. Functions, which it uses, allow the access to the intern functions of the computer simply and direct.

*independent: it can be used on any computer if it has the C compiler. *portability: it respect the standard ANSI-C; any program written in C can be used in another operating system but we have to recompile it. *extensible: it uses libraries of functions done by different developers.

Disadvantages: *comprehension: the code source can be not clear for others because of the use of compact expressions so we need to write commentary. *Portability and libraries of functions: the use of some specific functions (like the use of a special graphic card) that may threat the portability.

*style: unlike some other programming language (Pascal …), C doesn’t have a particular style of programming, so every programmer have to create his own style.

Bibliography: Cours Environnement de développement “Introduction”____Mme L.Ketari___ENSI Tunisie