This good tutorial on the Tool Command Language (Tcl) and its GUI toolkit (Tk) is in its third edition, and it has grown in size with each successive version. At present, the book is about 770 pages long and includes a CD-ROM that contains the examples and some selected Tcl/Tk freeware.

The book starts with the basic elements of Tcl, including commands, procedures, and data structures. Part 1, “Advanced Tcl,” deals with more advanced constructs such as regular expressions, namespaces, internationalization, TclHttpd (a Web server built in Tcl), and Safe-Tcl/Tk. Safe-Tcl/Tk is the name for restricted versions of Tcl and Tk that can execute scripts received from unknown sources without compromising local system security.

The second part of the book deals with Tk, beginning with a description of Tk and the basic Tk widgets. It describes the basic user interface elements such as buttons, menus, and scrollbars, each of which is also illustrated through a series of examples. This is followed by a section on more complex Tk programming issues, such as using the clipboard, dialogue boxes, and changing widget attributes and fonts. The last part of the book describes how to use C/C++ to extend the Tcl command set.

Overall, the book offers a very complete treatment of both Tcl and Tk. The description of Tk is particularly good, in that the examples are very clear and show readers exactly what the result should look like. The elements of the languages are presented in a logical manner, building upon each other. The author has kept pace with developments in this area by including new material on the TclHttpd, Safe-Tcl, and internationalization issues. Someone trying to learn the language can definitely save time by reading this book first.