Book Image

Tcl/Tk 8.5 Programming Cookbook

Book Image

Tcl/Tk 8.5 Programming Cookbook

Overview of this book

With Tcl/Tk, you can create full-featured cross-platform applications in a simple and easy-to-understand way without any expensive development package; the only tools required are a simple text editor and your imagination. This practical cookbook will help you to efficiently interact with editors, debuggers, and shell type interactive programs using Tcl/Tk 8. This cookbook will comprehensively guide you through practical implementation of Tcl/Tk 8.5 commands and tools. This book will take you through all the steps needed to become a productive programmer in Tcl/Tk 8. Right from guiding you through the basics to creating a stand-alone application, it provides complete explanation of all the steps along with handy tips and tricks. The book begins with an introduction to the Tcl shell, syntax, variables, and programming best practices in the language. It then explores procedures and the flow of events with control constructs followed by advanced error trapping and recovery. From Chapter 4, a detailed study of string expressions and handling enables you to handle various string functions and use lists to expand the string functionality. The book then discusses in-depth the Tcl Dictionary and how to utilize it to store and retrieve data. File operations and Tk GUI handling are covered extensively along with a developing a real-world address book application to practice the concepts learned.
Table of Contents (20 chapters)
Tcl/Tk 8.5 Programming Cookbook
About the Author
About the Reviewers

Locating a pattern within a string

Many times, you may have the need to determine if a specific pattern exists within a string. To accomplish this, Tcl provides the match keyword. Let's look at the syntax and then I will explain the major differences and the real strength of this keyword.

The string syntax is as follows:

string match nocase pattern string

When invoked with the match keyword, the string command will attempt to locate the pattern specified.

The following details the various methods in which the pattern can be passed and illustrates the special characters the pattern can store.

Special Characters



Matches any sequence within the string, including null strings.


Matches any single character in the string.


Matches any character in the set provided.

If chars contains a sequential notation of the form a-f, then any characters between a and f (a and f inclusive) will result in a match.


Matches the character specified in x.

This avoids...