TCL / TK in a Nutshell: A Desktop Quick Reference

The Tcl language and Tk graphical toolkit are simple and powerful building blocks for custom applications. The Tcl/Tk combination is increasingly popular because it lets you produce sophisticated graphical interfaces with a few easy commands, develop and change scripts quickly, and conveniently tie together existing utilities or programming libraries. One of the attractive features of Tcl/Tk is the wide variety of commands, many offering a wealth of options. Most of the things you'd like to do have been anticipated by the language's creator, John Ousterhout, or one of the developers of Tcl/Tk's many powerful extensions. Thus, you'll find that a command or option probably exists to provide just what you need. And that's why it's valuable to have a quick reference that briefly describes every command and option in the core Tcl/Tk distribution as well as the most popular extensions. Keep this book on your desk as you write scripts, and you'll be able to find almost instantly the particular option you need. Most chapters consist of alphabetical listings. Since Tk and mega-widget packages break down commands by widget, the chapters on these topics are organized by widget along with a section of core commands where appropriate. Contents include: Core Tcl and Tk commands and Tk widgets C interface (prototypes) Expect [incr Tcl] and [incr Tk] Tix TclX BLT Oratcl, SybTcl, and Tclodbc Table of Contents 7 Preface 11 Conventions 11 Contact O鈥橰eilly & Associates 12 About This Book 13 Acknowledgments 13 Chapter 1. Introduction 15 What Is Tcl? 15 Structure of This Book 16 Chapter 2. Tcl Core Commands 17 Overview 17 Basic Language Features 18 Command-Line Options 19 Environment Variables 19 Special Variables 19 Backslash Substitutions 20 Operators and Math Functions 21 Regular Expressions 23 Pattern Globbing 24 Predefined I/O Channel Identifiers 25 Group Listing of Commands 25 Alphabetical Summary of Commands 30 Chapter 3. Tk Core Commands 61 Example 61 Command-Line Options 63 Environment Variable 64 Special Variables 64 Group Listing of Tk Commands 64 Widget Overview 66 Standard Widget Options 67 Widget Commands 70 Utility Commands 115 Chapter 4. The Tcl C Interface 151 Constants 151 Data Types 152 Group Listing of Functions 154 Alphabetical Summary of Functions 162 Chapter 5. The Tk C Interface 170 Constants 170 Data Types 171 Group Listing of Functions 172 Alphabetical Summary of Functions 180 Chapter 6. Expect 188 Overview 188 Example 189 Command-Line Options 189 Environment Variables 191 Special Variables 191 Grouped Summary of Commands 193 Alphabetical Summary of Commands 195 Chapter 7. [incr Tcl] 207 Basic Class Definition 207 Special Variables 208 Group Listing of Commands 208 Example 208 Alphabetical Summary of Commands 209 Chapter 8. [incr Tk] 215 Basic Structure of a Mega-widget 215 Special Variable 216 Methods and Variables 216 Public Methods 216 Protected Methods 216 Protected Variables 217 Alphabetical Summary of Commands 218 Chapter 9. Tix 219 Tix Overview 219 Group Listing of Tix Commands 220 Tix Mega-widget Overview 222 Tix Mega-widgets 222 Tix Standard Widgets Overview 262 Display Items 262 Image Items 263 Imagetext Items 263 Text Items 264 Window Items 264 Tix Standard Widgets 265 Tix Core Commands 281 Tix Extensions to Tk image Command 292 Chapter 10. TclX 295 Special Variables 295 Group Listing of Commands 296 Alphabetical Summary of Commands 299 Chapter 11. BLT 328 Environment Variable 329 Group Listing of Commands 329 Alphabetical Summary of Commands 330 Chapter 12. Oratcl 402 Overview 402 Example 403 Environment Variables 403 Special Variables 403 Group Listing of Commands 405 Alphabetical Summary of Commands 405 Chapter 13. Sybtcl 410 Overview 410 Example 411 Environment Variables 411 Special Variables 411 Group Listing of Commands 413 Alphabetical Summary of Commands 413 Chapter 14. Tclodbc 417 Overview 417 Group Listing of Commands 418 Summary of Commands 419 Chapter 15. Hints and Tips for the Tcl Programmer 425 Think Commands, Not Statements 426 Comments Are Treated as Commands 428 A Symbolic Gesture 430 Lists Are Strings, but Not All Strings Are Lists 430 Indirect References 432 Executing Other Programs 433 When Is a Number Not a Number? 434 Quoting and More Quoting 435 Write Once, Run Where? 436 Filenames and Pathnames 436 End of Line Conventions 437 Determining Platform Specifics 437 Scanning and Formatting Binary Data 438 Common Tk Errors 438 Global Scope for -variable and -textvariable 438 The -command String Must Be a Tcl List 439 Use update to Refresh Widgets and for Event Processing 439 Use the Source, Luke! 440 Appendix. Tcl Resources 441 Web Sites 441 General 441 Tcl/Tk Extensions 442 Usenet Newsgroups 442 Books 442 Mailing Lists 442 Index 443 Symbols 443 A 443 B 443 C 444 D 445 E 445 F 446 G 447 H 447 I 447 J 448 K 448 L 448 M 448 N 449 O 449 P 449 Q 450 R 450 S 450 T 451 U 453 V 453 W 453 X 454 The Tcl language and Tk graphical toolkit are powerful building blocks for applications that feature a variety of commands with a wealth of options in each command. This quick reference briefly describes every command and option in the core of Tcl/Tk distribution.