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

Creating the Address Book application


As with any Tcl/Tk application, the manner in which the script is created determines the behavior. This is especially apparent when interacting with global variables. The global variables for our application are defined in the main body of the script to allow them to be accessed by the procedures. For the sake of formatting, I have used line continuation characters, "\" that may not be required in your text editor.

How to do it…

First, we will start by creating the graphical user interface. Enter the following into the address_book Tcl file:

# Load the Tk Package
package require Tk
# Configure the Window
wm title . "Address Book"
# Main Frame
frame .main -borderwidth 1 -relief solid -padx 10 -pady 10
# Entry Widgets
entry.main.efirst -width 25
entry .main.elast -width 25
entry .main.eaddress -width 50
entry .main.ecity -width 25
entry .main.estate -width 3
entry .main.ezip -width 5
entry .main.ephone -width 25
# Label Widgets
label .main.first -text "First...