Sign In Start Free Trial
Account

Add to playlist

Create a Playlist

Modal Close icon
You need to login to use this feature.
  • Book Overview & Buying Tcl/Tk 8.5 Programming Cookbook
  • Table Of Contents Toc
  • Feedback & Rating feedback
Tcl/Tk 8.5 Programming Cookbook

Tcl/Tk 8.5 Programming Cookbook

3 (7)
close
close
Tcl/Tk 8.5 Programming Cookbook

Tcl/Tk 8.5 Programming Cookbook

3 (7)

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)
close
close
Tcl/Tk 8.5 Programming Cookbook
Credits
About the Author
Acknowledgment
About the Reviewers
www.PacktPub.com
Preface

Returning a range of characters from a string


It is not uncommon to cut a string into its constituent parts. This allows the data to be stored in-line, without comma or space separation, thereby, minimizing the impact on the disk storage. To assist us in this, and other instances where we need to extract a range of characters from a string, Tcl has provided the range keyword.

The syntax of the string command is as follows:

string range string first last

When invoked with the range keyword, the string command will return all characters inclusive between those specified in the first and last location.

How to do it…

In the following example we will locate a range of characters contained within a string. Return values from the commands are provided for clarity. Enter the following command:

% string range abcdefg 2 4
cde

How it works…

As you can see, Tcl has returned the characters "cde", based on the index values passed. The string command returns a range of consecutive characters from the string...

Visually different images
CONTINUE READING
83
Tech Concepts
36
Programming languages
73
Tech Tools
Icon Unlimited access to the largest independent learning library in tech of over 8,000 expert-authored tech books and videos.
Icon Innovative learning tools, including AI book assistants, code context explainers, and text-to-speech.
Icon 50+ new titles added per month and exclusive early access to books as they are being written.
Tcl/Tk 8.5 Programming Cookbook
notes
bookmark Notes and Bookmarks search Search in title playlist Add to playlist font-size Font size

Change the font size

margin-width Margin width

Change margin width

day-mode Day/Sepia/Night Modes

Change background colour

Close icon Search
Country selected

Close icon Your notes and bookmarks

Confirmation

Modal Close icon
claim successful

Buy this book with your credits?

Modal Close icon
Are you sure you want to buy this book with one of your credits?
Close
YES, BUY

Submit Your Feedback

Modal Close icon
Modal Close icon
Modal Close icon