📘 ❞ C Programming Tutorial ❝ كتاب

عن 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
. .