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

Searching a list

As with any data contained within a program, it is the ability to locate and use that data that makes the program usable. To accomplish this, Tcl provides not only a command, but also a full complement of option flags to tailor the search. The lsearch command allows us to search a list to determine if it contains a particular element. Before we explore the syntax, we will first need to understand the options. The options are as follows:

Type of option

Option name


Matching style options


The pattern is a literal string that is compared against each element.



The pattern is a glob-style pattern that is matched against each element in the same manner, as a string match.



The pattern is treated as a regular expression and matched against each element.



The list elements are sorted in order. If specified, lsearch will use a more efficient search algorithm. The list is assumed to be sorted in ascending order and...