TCL /TK IN A NUTSHELL A Desktop Quick Reference TCL/TK IN A NUTSHELL A Desktop Quick Reference Paul Raines & Jeff Tranter Beijing • Cambridge • Farnham • Kưln • Sebastopol • Taipei • Tokyo About the Authors Paul Raines is a physicist and scientific programmer at Stanford University’s Stanford Linear Accelerator Center He is part of a large collaboration studying CP violation (why charge times parity is not conserved in some particle decays, an arcane research topic that bears on the more understandable question of why there is an excess of matter over antimatter in the universe) He is a huge advocate of scripting languages and has been using Tcl on various projects since 1992 He maintains a freely distributable quick-reference guide for Tcl/Tk, now published as O’Reilly & Associates’ Tcl/Tk Pocket Reference When he can get away from the lab, Paul enjoys hiking, bridge, and soccer He lives in San Mateo, California, with his wife Deborah and her horse and three cats Jeff Tranter works as a software designer for a Canadian telecommunications company and has been using Tcl since 1992 on a number of programming projects related to software tools and testing He is an active user of Linux, a contributor to the Linux Documentation Project, and author of the O’Reilly book Linux Multimedia Guide His hobbies include ham radio, playing guitar, and mountain biking Colophon The bird featured on the cover of Tck/Tk in a Nutshell is an ibis There are over 30 species of these wading birds distributed throughout the world, primarily in the warmer and tropical regions All ibises have long, narrow, sharply turned-down bills that they use to probe for insects, mollusks, and small crustaceans in mud or dirt They are strong fliers and swimmers, and most prefer living in the wetlands near fresh or salt water, marshes, and swamps They are very sociable and gregarious birds who nest in large colonies and travel in flocks When flying, all members of the flock alternate wing beats with gliding at approximately the same rate Fossils indicate that ibises have existed for about 60 million years, and records of human interaction with ibises dates back 5,000 years In ancient Egypt, the ibis was revered as the embodiment of Thoth, god of wisdom and scribe of the gods They are frequently depicted in Egyptian hieroglyphics, and cemeteries of mummified ibises have been discovered Today, the most widely distributed of all ibis species is the glossy ibis The glossy ibis is the last species of ibis known to exist in Europe and has spread to Africa, parts of Asia, and the Americas The most common species in the Americas is the white ibis, which has gradually spread northward and is now found as far north as Maine Edie Freedman designed the cover of this book using a 19th-century engraving from the Dover Pictorial Archive Kathleen Wilson produced the cover layout with QuarkXPress 3.3 using the ITC Garamond font Whenever possible, our books use RepKover™, a durable and flexible lay-flat binding If the page count exceeds RepKover's limit, perfect binding is used Madeleine Newell was the production editor for this book, and Sheryl Avruch was the production manager Cindy Kogut of Editorial Ink did the copyedit Nancy Crumpton wrote the index, and Seth Maislin produced the final version of the index Nicole Arigo and Nancy Wolfe Kotary provided quality assurance, and Sebastian Banker and Betty Hugh provided production assistance The inside layout was designed by Nancy Priest and implemented in gtroff by Lenny Muellner The text and heading fonts are ITC Garamond Light and Garamond Book The screen shots that appear in the book were created in Adobe Photoshop 4.0 by Robert Romano This colophon was written by Clairemarie Fisher O’Leary ... languages and has been using Tcl on various projects since 1992 He maintains a freely distributable quick-reference guide for Tcl/ Tk, now published as O’Reilly & Associates’ Tcl/ Tk Pocket Reference... TCL /TK IN A NUTSHELL A Desktop Quick Reference TCL/ TK IN A NUTSHELL A Desktop Quick Reference Paul Raines & Jeff Tranter... Tranter works as a software designer for a Canadian telecommunications company and has been using Tcl since 1992 on a number of programming projects related to software tools and testing He is an