1. Chapter 1 Introduction

   1. What Is Tcl?

   2. Structure of This Book

2. Chapter 2 Tcl Core Commands

   1. Overview

   2. Basic Language Features

   3. Command-Line Options

   4. Environment Variables

   5. Special Variables

   6. Backslash Substitutions

   7. Operators and Math Functions

   8. Regular Expressions

   9. Pattern Globbing

   10. Predefined I/O Channel Identifiers

   11. Group Listing of Commands

   12. Alphabetical Summary of Commands

3. Chapter 3 Tk Core Commands

   1. Example

   2. Command-Line Options

   3. Environment Variable

   4. Special Variables

   5. Group Listing of Tk Commands

   6. Widget Overview

   7. Widget Commands

   8. Utility Commands

4. Chapter 4 The Tcl C Interface

   1. Constants

   2. Data Types

   3. Group Listing of Functions

   4. Alphabetical Summary of Functions

5. Chapter 5 The Tk C Interface

   1. Constants

   2. Data Types

   3. Group Listing of Functions

   4. Alphabetical Summary of Functions

6. Chapter 6 Expect

   1. Overview

   2. Example

   3. Command-Line Options

   4. Environment Variables

   5. Special Variables

   6. Grouped Summary of Commands

   7. Alphabetical Summary of Commands

7. Chapter 7 [incr Tcl]

   1. Basic Class Definition

   2. Special Variables

   3. Group Listing of Commands

   4. Example

   5. Alphabetical Summary of Commands

8. Chapter 8 [incr Tk]

   1. Basic Structure of a Mega-widget

   2. Special Variable

   3. Methods and Variables

   4. Alphabetical Summary of Commands

9. Chapter 9 Tix

   1. Tix Overview

   2. Special Variables

   3. Group Listing of Tix Commands

   4. Tix Mega-widget Overview

   5. Tix Mega-widgets

   6. Tix Standard Widgets Overview

   7. Tix Standard Widgets

   8. Tix Core Commands

   9. Tix Extensions to Tk image Command

10. Chapter 10 TclX

    1. Special Variables

    2. Group Listing of Commands

    3. Alphabetical Summary of Commands

11. Chapter 11 BLT

    1. Environment Variable

    2. Special Variables

    3. Group Listing of Commands

    4. Alphabetical Summary of Commands

12. Chapter 12 Oratcl

    1. Overview

    2. Example

    3. Environment Variables

    4. Special Variables

    5. Group Listing of Commands

    6. Alphabetical Summary of Commands

13. Chapter 13 Sybtcl

    1. Overview

    2. Example

    3. Environment Variables

    4. Special Variables

    5. Group Listing of Commands

    6. Alphabetical Summary of Commands

14. Chapter 14 Tclodbc

    1. Overview

    2. Group Listing of Commands

    3. Summary of Commands

15. Chapter 15 Hints and Tips for the Tcl Programmer

    1. Think Commands, Not Statements

    2. Comments Are Treated as Commands

    3. A Symbolic Gesture

    4. Lists Are Strings, but Not All Strings Are Lists

    5. Indirect References

    6. Executing Other Programs

    7. When Is a Number Not a Number?

    8. Quoting and More Quoting

    9. Write Once, Run Where?

    10. Common Tk Errors

    11. Use the Source, Luke!

1. Appendix Tcl Resources

   1. Web Sites

   2. Usenet Newsgroups

   3. Mailing Lists

2. Colophon

Our look is the result of reader comments, our own experimentation, and feedback from distribution channels. Distinctive covers complement our distinctive approach to technical topics, breathing personality and life into potentially dry subjects. The bird featured on the cover of Tcl/Tk in a Nutshell is an ibis. There are over 30 species of these wading birds distributed throughout the world, primarily in the warmer and tropical regions. All ibises have long, narrow, sharply turned-down bills that they use to probe for insects, mollusks, and small crustaceans in mud or dirt. They are strong fliers and swimmers and most prefer living in the wetlands near fresh or salt water, marshes and swamps. They are very sociable and gregarious birds who nest in large colonies and travel in flocks. When flying, all members of the flock alternate wing beats with gliding at approximately the same rate.

Fossils indicate that ibises have existed for about 60 million years, and records of human interaction with ibises dates back 5,000 years. In ancient Egypt the ibis was revered as the embodiment of Thoth, god of wisdom and scribe of the gods. They are frequently depicted in Egyptian hieroglyphics, and cemetaries of mummified ibises have been discovered.

Today, the most widely distributed of all ibis species is the glossy ibis. The glossy ibis is the last species of ibis known to exist in Europe and has spread to Africa, parts of Asia, and the Americas. The most common species in the Americas is the white ibis, which has gradually spread northward and is now found as far north as Maine. Edie Freedman designed the cover of this book, (and Hanna Dyer designed the CD label) using a 19th-century engraving from the Dover Pictorial Archive. The cover layout was produced with Quark XPress 3.3 using the ITC Garamond font. Whenever possible, our books use RepKover™, a durable and flexible lay-flat binding. If the page count exceeds RepKover's™ limit, perfect binding is used. The inside layout was designed by Nancy Priest and implemented in gtroff by Lenny Muellner. The text and heading fonts are ITC Garamond Light and Garamond Book. The illustrations that appear in the book were created in Macromedia Freehand 7.0 and screen shots were created in Adobe Photoshop 4.0 by Robert Romano. This colophon was written by Clairemarie Fisher O'Leary.