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

Performing character substitution on a string

If regexp is a Find function, then regsub is equivalent to Find and Replace. The regsub command accepts a string and using Regular Expression pattern matching, it locates and, if desired, replaces the pattern with the desired value. The syntax of regsub is similar to regexp as are the switches. However, additional control over the substitution is added. The switches are as listed next:




Causes the command to perform substitution for each match found

The & and \n sequences are handled for each substitution


Allows use of expanded regular expression wherein whitespace and comments are ignored


Enables newline-sensitive matching similar to passing the linestop and lineanchor switches


Changes the behavior of [^] bracket expressions so that they stop at newline characters


Changes the behavior of ^ and $ (anchors) so that they match both the beginning and end of...