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
Credits
About the Author
Acknowledgment
About the Reviewers
www.PacktPub.com
Preface

Introduction


Thankfully, we are not limited to dialog windows of our own creation. Tk provides a full suite of predefined dialog windows to assist us in the more common tasks of collecting, notifying, and general interactions with the end user. These dialog windows allow us to rapidly create an interface that is both professional in appearance and familiar in functionality with minimum effort. As with all Tk-based windows, the appearance of the native OS is duplicated automatically.

Although you are displaying a full graphical window, the dialog windows are invoked in the same manner as a Tcl command. As such, to assign the return values from the various dialog windows to a variable, you must utilize the set command in conjunction with the dialog commands.

Unless otherwise stated, we will need to access wish from the command line to complete the following examples. Launch the wish shell appropriately for your operating system and follow the instructions provided in each section.