21世纪C语言：探索现代编程技术

需积分: 0 77 浏览量更新于2024-07-23 收藏 7.28MB PDF 举报

"21st Century C" 《21世纪C语言》是一本专注于介绍现代C语言技术的书籍，由Ben Klemens撰写。这本书旨在揭示C语言在其他传统教材中未涵盖的最新发展，强调C语言作为现代编程语言的适应性和效率。C语言不仅是许多现代编程语言的基础，而且在编写高性能、前沿应用方面具有独特优势。作者鼓励读者摆脱过时的编程习惯，转而采用更适合现代环境的方法。本书适合所有级别的程序员，无论你已经是哪种编程语言的专家，都能从中发现C语言的独特魅力。书中可能涵盖了如下关键知识点： 1. **C语言的现代化特性**：讨论了C99和C11标准引入的新特性，如柔性数组成员、inline函数、变量长度数组、_Bool类型等，这些都是传统C语言教程中可能忽略的内容。 2. **内存管理**：深入讲解C语言中的动态内存分配、内存对齐以及如何避免内存泄漏，这对于高效和安全的编程至关重要。 3. **指针与数据结构**：详细阐述C语言中的指针操作和复杂数据结构的实现，包括链表、树、图等，以及如何利用指针优化代码性能。 4. **错误处理和调试**：介绍如何有效地处理运行时错误，使用assert宏和其他调试技巧，帮助开发者构建健壮的程序。 5. **预处理器和宏**：探讨预处理器的使用，包括宏定义和条件编译，以及如何谨慎使用以避免常见陷阱。 6. **并发与多线程**：C语言如何支持多线程编程，包括线程的创建、同步和通信，这对于编写现代并行应用非常重要。 7. **标准化和跨平台编程**：解释如何遵循ANSI/ISO C标准进行编写，确保代码能在不同平台上移植。 8. **性能优化**：讲解如何通过C语言特性进行性能调优，如内联函数、预编译头文件等。 9. **现代开发工具**：介绍现代IDE、版本控制系统、构建系统（如Make）和调试工具的使用，以提升开发效率。 10. **最佳实践**：提供C语言编程的最佳实践，包括代码风格、注释规范和测试策略，帮助编写清晰、可维护的代码。《21世纪C语言》是一本全面且现代的C语言指南，它不仅更新了传统的C语言教学内容，还介绍了如何利用C语言的优势来应对当今计算环境的挑战。对于任何希望深入理解C语言或者想要提升C语言编程技能的人来说，这本书都是一个宝贵的资源。

would be reviled. And indeed, this standard was controversial. There are two com-

mon ways to express a complex variable (rectangular and polar coordinates)—so

where does the ISO get off picking one? Why do we need a mechanism for variable-

length macro inputs when all the good code got written without it? In other words,

the purists accused the ISO of selling out to the pressure for more features.

As of this writing, most compilers support C99 plus or minus a few caveats; the

long double type seems to cause a lot of trouble, for example. However, there is

one notable exception to this broad consensus: Microsoft currently refuses to add

C99 support to its Visual Studio C++ compiler. The section “Compiling C with

Windows” on page 6 covers some of the many ways to compile C code for

Windows, so not using Visual Studio is at most an inconvenience, and having a

major establishment player tell us that we can’t use ISO-standard C only bolsters

the punk rock of it all.

C11

Self-conscious about the accusations of selling out, the ISO made few serious

changes in the third edition of the standard. We got a means of writing type-generic

functions, and things were modernized to further acknowledge that security mat-

ters and that not everybody speaks English.

I’m writing this in 2012, shortly after the C11 standard came out in December of

2011, and there’s already some support from compilers and libraries.

The POSIX Standard

That’s the state of things as far as C itself goes, but the language coevolved with the

Unix operating system, and you will see throughout the book that the interrelationship

matters for day-to-day work. If something is easy on the Unix command line, then it is

probably because it is easy in C; Unix tools are often written to facilitate writing C code.

Unix

C and Unix were designed at Bell Labs in the early 1970s. During most of the 20th

century, Bell was being investigated for monopolistic practices, and one of its

agreements with the US federal government included promises that Bell would not

expand its reach into software. So Unix was given away for free for researchers to

dissect and rebuild. The name Unix is a trademark, originally owned by Bell Labs

and subsequently traded off like a baseball card among a number of companies.

Variants of Unix blossomed, as the code was looked over, reimplemented, and im-

proved in different ways by diverse hackers. It just takes one little incompatibility to

make a program or script unportable, so the need for some standardization quickly

became apparent.

xiv | Preface

POSIX

This standard, first established by the Institute of Electrical and Electronics Engi-

neers (IEEE) in 1988, provided a common basis for Unix-like operating systems.

It specifies how the shell should work, what to expect from commands like ls and

grep, and a number of C libraries that C authors can expect to have available. For

example, the pipes that command-line users use to string together commands are

specified in detail here, which means C’s popen (pipe open) function is POSIX-

standard, not ISO C standard. The POSIX standard has been revised many times;

the version as of this writing is POSIX:2008, and is what I am referring to when I

say that something is POSIX-standard. A POSIX-standard system must have a C

compiler available, via the command name c99.

This book will make use of the POSIX standard, though I’ll tell you when.

With the exception of many members of a family of OSes from Microsoft, just

about every current operating system you could name is built on a POSIX-com-

pliant base: Linux, Mac OS X, iOS, webOS, Solaris, BSD—even Windows servers

offer a POSIX subsystem. And for the hold-out OSes, “Compiling C with Win-

dows” on page 6 will show you how to install a POSIX subsystem.

Finally, there are two more implementations of POSIX worth noting because of their

prevalence and influence:

BSD

After Unix was sent out from Bell Labs for researchers to dissect, the nice people

at the University of California, Berkeley, made major improvements, eventually

rewriting the entire Unix code base to produce the Berkeley Software Distribution.

If you are using a computer from Apple, Inc., you are using BSD with an attractive

graphical frontend. BSD goes beyond POSIX in several respects, and we’ll see a

function or two that are not part of the POSIX standard but are too useful to pass

up (most notably the lifesaver that is asprintf).

GNU

It stands for GNU’s Not Unix, and is the other big success story in independently

reimplementing and improving on the Unix environment. The great majority of

Linux distributions use GNU tools throughout. There are very good odds that you

have the GNU Compiler Collection (gcc) on your POSIX box—even BSD uses it.

Again, the gcc defines a de facto standard that extends C and POSIX in a few ways,

and I will be explicit when making use of those extensions.

Legally, the BSD license is slightly more permissive than the GNU license. Because some

parties are deeply concerned with the political and business implications of the licenses,

one can typically find both GNU and BSD versions of most tools. For example, both

the GNU Compiler Collection (gcc) and the BSD’s clang are top-notch C compilers.

The authors from both camps closely watch and learn from each other’s work, so we

can expect that the differences that currently exist will tend to even out over time.

Preface | xv

The Legal Sidebar

US law no longer has a registration system for copyright: with few exceptions, as soon

as anybody writes something down, it is copyrighted.

Of course, distribution of a library depends on copying from hard drive to hard drive,

and there are a number of common mechanisms for granting the right to copy a copy-

righted work with little hassle.

• The GNU Public License allows unlimited copying and use of the source code and

its executable version. There is one major condition: If you distribute a program

or library based on the GPLed source code, then you must distribute the source

code to your program. Note well that if you use your program in-house and don’t

distribute it, this condition doesn’t hold, and you have no obligation to distribute

source. Running a GPLed program, like compiling your code with gcc, does not

in itself obligate you to distribute source code, because the program output (such

as the executable you just compiled) is not considered to be based on or a derivative

of gcc. [Example: the GNU Scientific Library.]

• The Lesser GPL is much like the GPL, but it explicitly stipulates that if you are

linking to an LGPL library as a shared library, then your code doesn’t count as a

derivative work, and you aren’t obligated to distribute source. That is, you can

distribute closed-source code that links to an LGPL library. [Example: GLib.]

• The BSD license requires that you preserve copyrights and disclaimers for BSD-

licensed source code, but doesn’t require that you redistribute source code.

[Example: Libxml2, under the BSD-like MIT license.]

Please note the usual disclaimer: I am not a lawyer, and this is a sidebar summary of

several rather long legal documents. Read the documents themselves or consult a lawyer

if you are unsure about how the details apply to your situation.

Some Logistics

Conventions Used in This Book

The following typographical conventions are used in this book:

Italic

Indicates new terms, filenames and file paths, URLs, and email addresses. Many

new terms are defined in a glossary at the end of this book.

Constant width

Used for program listings, as well as within paragraphs to refer to program elements

such as variable or function names, databases, data types, environment variables,

statements, and keywords.

xvi | Preface

剩余297页未读，继续阅读

caldur

粉丝: 0
资源: 1

21世纪C语言：探索现代编程技术

21st Century C.pdf

21世纪C语言教程（21st Century C, 2nd Edition）-2015年英文原版，0积分

[含随书源码]21st Century C 2nd Edition(C程序设计新思维 )

21st Century C：现代C编程指南

《21st Century C》第二版：现代C语言编程指南

21st Century C - 信息技术新篇章

Compiler Contruction for the 21st Century

A View of 20th and 21st Century Software Engineering

21st-Century-Examples, _21st Klemens的世纪C_示例.zip

Jist.Works.Best.Jobs.for.the.21st.Century.3rd.Ed.eBook-DDU.pdf

最新资源