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

Chapter 5. Expanding String Functionality Using Lists

In this chapter, we will cover the following topics:

  • Creating a list

  • Joining two lists

  • Joining list elements

  • Appending list elements

  • Assigning list elements to variables

  • Retrieving an element from a list

  • Inserting elements into a list

  • Determining the number of elements

  • Getting a list element

  • Repeating elements

  • Replacing elements

  • Reversing elements

  • Searching a list

  • Editing a list

  • Sorting a list

  • Splitting a string into a list


Now that we have a firm grasp on the string type, let's look at the Tcl command list. As you might have discerned from the command name, this command is used to create and manage lists of information. While the various string handling commands allow for the creation of a string containing anything from a single character to larger text files, the list allows you to create, manipulate, and utilize a list of arguments in the same manner as a shopping list. In Tcl, each of the separate items in a list are referred to as elements...