Tcl/Tk 8.5 Programming Cookbook

Chapter 7. File Operations

In this chapter, we will cover:

• Opening a file
• Configuring a file
• Opening a command pipeline
• Writing a file
• Reading a file
• Closing a file
• File handling

Introduction

Up to this point, we have primarily entered the data through the command line. While this is fine for small scripts, it does not provide the means to obtain and store information. To accomplish this, we need to read and write to the file system.

File access is a basic requirement for dynamic programs. Whether it's a text-based configuration file or images to display, most programs use the file system as the storage and retrieval location. All storage needs have—historically and continually—relied on the file system.

Although we will be dealing with strings in the coming ...