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Preface
The Win32 system services are the innovative, cutting-edge capabilities that make Windows 2000 and Windows 98 interesting and exciting. Amid all of the media attention surrounding Windows 2000 and 98, you have probably heard and read about many of the modern capabilities that these operating systems contain:
- Processes and threads
- Synchronization
- Remote Procedure Calls (RPCs) and DCOM (Distributed COM)
- Event logging
- Network communications
- TCP/IP network communications
- File mapping and Active Directory
- Interprocess and Interprocessor communication
- Compressed file access
- Network drive- and printer-sharing
- Serial communications
- Services (background processing like UNIX daemons)
- Object and file security
The goal of this book is to show you how to use all of these different services in your own applications. This book contains hundreds of concise, clear, and easy-to-understand example programs and explanations. The examples show you how to access the system services listed above, as well as many others. You can use these examples directly, to understand the concepts. You can also drop the sample code into your own programs and then extend it to give your applications new and useful features.
By learning about the many and varied system services available inside of Windows 2000 and 98, you can make your programs much more interesting to the user. For example, if you learn about threads and then add multiple threads to your applications, the user gets a much smoother interface (see Chapter 6). Your program will also take advantage of multiple processors on machines that have them. If you add network support to your applications, the user is able to access network resources that are unavailable on a single machine (see Chapter 8). If you add modem support, you can use it to let the user dial into a remote system (see Chapter 11). Or you might use a modem to let the user dial a support line or registration system for a product that your company sells.
The goal of this book is to give you a thorough and clear understanding of the system services so that you can take advantage of all of the capabilities that Windows has to offer.
Audience
This book is designed for two types of people. If you are a devoted connoisseur or student of programming, the study of the system functions is interesting in its own right. It's fun to see what functions are available, and to try to think of ways to exploit those capabilities. One way to use this book is to simply browse through it and see what is possible. You can work with the examples and extend them in ways that you find enjoyable.
If, on the other hand, you are a programmer with a deadline, enjoyable entertainment is probably not your goal. You may have looked at the huge number of functions in the Windows API and found it discouraging. Where do you start? What you need is a set of useful examples and clear explanations that quickly solve your specific problems. You will find this book useful because it organizes concepts logically and provides the material that you need to master a specific topic very quickly.
If you are migrating from another operating system to Windows, this book will help you to quickly map your existing knowledge into the Windows framework. See Chapter 1 for a list of the 121 most common programming questions in Windows, as well as for the locations of the sections that contain the answers.
Organization
This book is organized by functional categories. For example, Chapter 2 talks about all of the functions that pertain to file input/output and file handling. Chapter 3 deals with disk drives. Chapter 4 discusses directories. Chapter 5 talks about the next-generation directory services, known as Active Directory in Windows 2000. Chapter 6 talks about processes and threads. You will find that each chapter starts with a general overview of the topic, followed by sections that describe and give examples for subsets of functions.
In many chapters you will find integrating examples that combine different capabilities from several chapters to create larger applications. Many of these larger examples form complete applications that you can use as starting points for new projects of your own.
Philosophy
Several principles guide the content of this book. The first principle is the most important and is therefore used throughout: it is simplicity. There is nothing worse than looking up a function, only to find that its example is embedded within sample code that takes three days to comprehend because it is 28 pages long. In all cases a function is first demonstrated in code that is as simple as possible so that you can extract the essence of each one very quickly. They may then be integrated into larger examples. In many cases you will look at the example code and say to yourself, "This is easy!" That is exactly the intent. If the book makes everything look simple and easy for you, then it has accomplished its goal.
The second principle driving this book is the idea of functional families. Functions in the 32-bit API very rarely exist on their own-it is far more common to find small collections of functions that relate very closely to one another. For example, the ReadFile function reads from a file, but you must open the file with CreateFile before you can read from it and then remember to close it with CloseHandle afterwards (see Chapter 2). These functions belong to a family. In this book you will generally find small groupings of functions described as logical units.
The third principle in this book is that of currency. The Windows API has been around for some time, and when you look at it you will find that there is a certain amount of layering. The documentation will often say things like, "this function is retained for compatibility with version 1.8, but has been superseded by function xyz." This book deals only with the current functions, and leaves the superseded ones to die in peace.
The last principle guiding this book is independence. Each chapter in this book is as stand-alone as possible, so that you can jump around in the book as you please. In cases where material from other chapters is important, you will find references to the related sections.
Prerequisites and Languages
This book makes no assumptions about your former knowledge of systems programming in Windows or in any other system. Its only real assumption is that you know C and/or C++. You will find that the example code can be divided into two categories:
- Text examples that run in "console mode." These programs run from the MS-DOS prompt, accept keyboard input, and produce text output. They form the vast majority of the code in this book because they are simple. These programs are C++- compatible, but the only elements really being used from C++ are the I/O stream libraries.
- "Windows" programs that use the Windows GUI. These programs use C++ and the Microsoft Foundation Class library (MFC). The book Visual C++: Developing Professional Applications for Windows 98 and NT using MFC, by Marshall Brain and Lance Lovette (ISBN 0-13-085121-3), describes how to create programs with MFC, and will be useful as a tool to help you understand these examples if you are not already familiar with MFC. You can develop C-language Windows programs using only the Win32 API. However, the Visual C++ tools make low-level Win32 programming easier. But to take advantage of the Visual C++ and MFC tools, you should have a good grasp of the underlying Win32 API.
If you are a C programmer with no C++ experience, you will have no trouble understanding the console programs. The only unusual thing you
