كتاب C Programming Tutorial

Preface xi Preface Every program is limited by the language which is used to writ e it. C is a programmer’s language. Unlike BASIC or Pascal, C was not wri tten as a teaching aid, but as an implementation language. C is a compu ter language and a programming tool which has grown popular because progr ammers like it! It is a tricky language but a masterful one. Sceptics have said that it is a language in which everything which can go wrong does go wron g. True, it does not do much hand holding, but also it does not hold anythi ng back. If you have come to C in the hope of finding a powerful language for writing everyday computer programs, then you will not be disappoint ed. C is ideally suited to modern computers and modern programming. This book is a tutorial. Its aim is to teach C to a beginner, but with enough of the details so as not be outgrown as the years go by. I t presumes that you have some previous aquaintance with programming — y ou need to know what a variable is and what a function is — but you do not ne ed much experience. It is not essential to follow the order of the cha pters rigorously, but if you are a beginner to C it is recommended. When it comes d own to it, most languages have basically the same kinds of features : variables, ways of making loops, ways of making decisions, ways of accessing files etc. If you want to plan your assault on C, think about what you already kn ow about programming and what you expect to look for in C. You will most likely find all of those things and more, as you work though the chapters. The examples programs range from quick one-function progra ms, which do no more than illustrate the sole use of one simple feature, to complete application examples occupying several pages. In places th ese examples make use of features before they have properly been explained. Th ese programs serve as a taster of what is to come. Mark Burgess. 1987, 1999 This book was first written in 1987; this new edition was updat ed and rewritten in 1999. The book was originally published by Dabs Press. Since the book has gone out of print, David Atherton of Dabs and I agr eed to release the manuscript, as per the original contract. This n ew edition is written in Texinfo, which is a documentation system that use s a single source file to produce both on-line information and printed output. You can read this tutorial online, using either the Emacs Info reader, th e standalone Info reader, or a World Wide Web browser, or you can read this same t ext as a typeset, printed book. Table of Contents i Table of Contents Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 High Levels and Low Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Basic ideas about C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.3 The Compiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.4 Errors .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.5 Use of Upper and Lower Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 1.6 Declarations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.7 Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2 Reserved words and an example . . . . . . . . . . . 11 2.1 The printf() function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2.2 Example Listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.3 Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.4 Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3 Operating systems and environments . . . . . . 13 3.1 Files and Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.2 Filenames . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.3 Command Languages and Consoles . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.4 Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4 Libraries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 4.1 Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 5 Programming style . . . . . . . . . . . . . . . . . . . . . . . 21 6 The form of a C program . . . . . . . . . . . . . . . . . 23 6.1 Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 7 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 7.1 Example 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 7.2 Example 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 7.3 Question . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 ii 8 Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 8.1 Structure diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 8.2 Program Listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 8.3 Functions with values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 8.4 Breaking out early . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 8.5 The exit() function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 8.6 Functions and Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 8.7 Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 9 Variables, Types and Declarations . . . . . . . . . 37 9.1 Declarations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 9.2 Where to declare things . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 9.3 Declarations and Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 9.4 Individual Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 9.4.1 char . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 9.4.2 Listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 9.4.3 Integers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 9.5 Whole numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 9.5.1 Floating Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 9.6 Choosing Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 9.7 Assigning variables to one another . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 9.8 Types and The Cast Operator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 9.9 Storage class static and extern . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 9.10 Functions, Types and Declarations . . . . . . . . . . . . . . . . . . . . . . . . . 48 9.11 Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 10 Parameters and Functions . . . . . . . . . . . . . . . . 51 10.1 Declaring Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 10.2 Value Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 10.3 Functions as actual parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 10.4 Example Listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 10.5 Example Listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 10.6 Variable Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 10.7 Example Listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 10.8 Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 11 Scope : Local And Global . . . . . . . . . . . . . . . . 65 11.1 Global Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 11.2 Local Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 11.3 Communication : parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 11.4 Example Listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 11.5 Style Note . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 11.6 Scope and Style . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 11.7 Questions . .
-
من كتب لغة السي كتب لغات البرمجة - مكتبة كتب تقنية المعلومات.