C in a Nutshell

1291 Pages·2005·4.63 MB·English

by  Peter Prinz

C in a Nutshell
Peter Prinz
Tony Crawford
Published by O’Reilly Media
Beijing ⋅ Cambridge ⋅ Farnham ⋅ Köln ⋅ Sebastopol ⋅ Tokyo
Preface
This book is a complete reference to the C programming language and the C
runtime library. As a Nutshell book, its purpose is to serve as a convenient,
reliable companion for C programmers in their day-to-day work. It describes all
the elements of the language and illustrates their use with numerous examples.
The present description of the C language is based on the 1999 international C
standard, ISO/IEC 9899:1999, including the Technical Corrigenda, TC1 of 2001
and TC2 of 2004. This standard, widely known as C99, is an extension of the
ISO/IEC 9899:1990 standard and the 1995 Normative Addendum 1 (ISO/IEC
9899/AMD1:1995). The 1990 ISO/IEC standard corresponds to the ANSI
standard X3.159, which was ratified in late 1989 and is commonly called ANSI
C or C89.
The new features of the 1999 C standard are not yet fully supported by all
compilers and standard library implementations. In this book we have therefore
labeled 1999 extensions, such as new standard library functions that were not
mentioned in earlier standards, with the abbreviation C99.
This book is not an introduction to programming in C. Although it covers the
fundamentals of the language, it is not organized or written as a tutorial. If you
are new to C, we assume that you have read at least one of the many
introductory books, or that you are familiar with a related language, such as Java
or C++.
How This Book Is Organized
This book is divided into three parts. The first part describes the C language in
the strict sense of the term; the second part describes the standard library; and
the third part describes the process of compiling and testing programs with the
popular tools in the GNU software collection.
Part I
Part I, which deals with the C language, includes Chapters 1 through 14. After
Chapter 1, which describes the general concepts and elements of the language,
each chapter is devoted to a specific topic, such as types, statements, or pointers.
Although the topics are ordered so that the fundamental concepts for each new
topic have been presented in an earlier chapter—types, for example, are
described before expressions and operators, which come before statements, and
so on—you may sometimes need to follow references to later chapters to fill in
related details. For example, some discussion of pointers and arrays is necessary
in Chapter 5 (which covers expressions and operators), even though pointers and
arrays are not described in full detail until Chapters 8 and 9.
Chapter 1, Language Basics
Describes the characteristics of the language and how C programs are
structured and compiled. This chapter introduces basic concepts such
as the translation unit, character sets, and identifiers.
Chapter 2, Types
Provides an overview of types in C and describes the basic types, the
type void, and enumerated types.
Chapter 3, Literals
Describes numeric constants, character constants, and string literals,
including escape sequences.
Chapter 4, Type Conversions
Describes implicit and explicit type conversions, including integer
promotion and the usual arithmetic conversions.
Chapter 5, Expressions and Operators
Describes the evaluation of expressions, all the operators, and their
compatible operands.
Chapter 6, Statements
Describes C statements such as blocks, loops, and jumps.
Chapter 7, Functions
Describes function definitions and function calls, including recursive
and inline functions.
Chapter 8, Arrays
Describes fixed-length and variable-length arrays, including strings,
array initialization, and multidimensional arrays.
Chapter 9, Pointers
Describes the definition and use of pointers to objects and functions.
Chapter 10, Structures, Unions, and Bit-Fields
Describes the organization of data in these user-defined derived types.
Chapter 11, Declarations
Describes the general syntax of a declaration, identifier linkage, and
the storage duration of objects.
Chapter 12, Dynamic Memory Management
Describes the standard library's dynamic memory management
functions, illustrating their use in a sample implementation of a
generalized binary tree.
Chapter 13, Input and Output
Describes the C concept of input and output, with an overview of the
use of the standard I/O library.
Chapter 14, Preprocessing Directives
Describes the definition and use of macros, conditional compiling, and
all the other preprocessor directives and operators.
Part II
Part II, consisting of Chapters 15, 16, and 17, is devoted to the C standard
library. It provides an overview of standard headers and also contains a detailed
function reference.
Chapter 15, The Standard Headers
Describes contents of the headers and their use. The headers contain
all of the standard library's macros and type definitions.
Chapter 16, Functions at a Glance
Provides an overview of the standard library functions, organized by
areas of application, such as "Mathematical Functions," "Time and
Date Functions," and so on.
Chapter 17, Standard Library Functions
Describes each standard library function in detail, in alphabetical
order, and contains examples to illustrate the use of each function.
Part III
The third part of this book provides the necessary knowledge of the C
programmer's basic tools: the compiler, the make utility, and the debugger. The
tools described here are those in the GNU software collection.
Chapter 18, Compiling with GCC
Describes the principal capabilities that the widely used compiler
offers for C programmers.
Chapter 19, Using make to Build C Programs
Describes how to use the make program to automate the compiling
process for large programs.
Chapter 20, Debugging C Programs with GDB
Describes how to run a program under the control of the GNU
debugger and how to analyze programs' runtime behavior to find
logical errors.
Further Reading
In addition to works mentioned at appropriate points in the text, there are a
number of resources for readers who want more technical detail than even this
book can provide. The international working group on C standardization has an
official home page at http://www.open-std.org/jtc1/sc22/wg14, with links to the
latest version of the C99 standard and current projects of the working group.
For readers who are interested in not only the what and how of C, but also the
why, the WG14 site also has a link to the "C99 Rationale": this is a
nonnormative but current document that describes some of the motivations and
constraints involved in the standardization process. The C89 Rationale is online
at http://www.lysator.liu.se/c/rat/title.html. Furthermore, for those who may
wonder how C "got to be that way" in the first place, the originator of C, Dennis
Ritchie, has an article titled "The Development of the C Language" as well as
other historical documents on his Bell Labs web site, http://cm.bell-
labs.com/cm/cs/who/dmr.
Readers who want details on floating-point math beyond the scope of C may
wish to start with David Goldberg's thorough introduction, "What Every
Computer Scientist Should Know About Floating-Point Arithmetic," currently
available online at http://docs.sun.com/source/806-3568/ncg_goldberg.html.
Conventions Used in This Book
The following typographical conventions are used in this book:
Italic
Highlights new terms; indicates filenames, file extensions, URLs,
directories, and Unix utilities.
Constant width
Indicates all elements of C source code: keywords, operators,
variables, functions, macros, types, parameters, and literals. Also used
for console commands and options, and the output from such
commands.
Constant width bold
Highlights the function or statement under discussion in code
examples. In compiler, make, and debugger sessions, this font
indicates command input to be typed literally by the user.
Constant width italic
Indicates parameters in function prototypes, or placeholders to be
replaced with your own values.
Plain text
Indicates keys such as Return, Tab, and Ctrl.
TIP
This icon signifies a tip, suggestion, or general note.
WARNING
This icon signifies a warning or caution.
Using Code Examples
This book is here to help you get your job done. In general, you may use the