Tcl and the Tk Toolkit

The Tcl scripting language and the Tk toolkit — a programming environment for creating graphical user interfaces under X Windows — together represent one of the most exciting innovations in X Window System programming. Because Tcl and Tk are so easy to learn, extremely powerful, and contain so many sophisticated features, they have dramatically reduced development time for thousands of X programmers.

Written by the creator of Tcl and Tk, this book is the single authoritative resource for anyone who wants to work with this extraordinary environment. The book offers an introduction and overview of Tcl and Tk and then presents detailed instructions for script writing in Tcl and working with the Tk toolkit.

You will discover how Tk's windowing shell, wish, enables you to develop window-based applications with amazingly few lines of code. You will also find information on Tk's novel and powerful facility for linking applications. Many other features are also described, such as Tk's hypertext and hypergraphic widgets and Tcl's facilities for procedures, list management, and subprocess execution.

For interested readers, the book also describes the C interfaces for Tcl and Tk, showing how to extend their built-in features by writing new C commands.

Upon reading this book, you will learn how to produce far more powerful X Windows System applications in a fraction of the time that used to be required.

1. Introduction
1. Introduction
2. Organization of the book
3. Notation
4. Pronunciation
5. Versions
2. An Overview of Tcl and Tk
1. Getting started
2. Hello world with Tk
3. Script files
4. Variables and substitutions
5. Control structures
6. On the Tcl language
7. Event bindings
8. Subprocesses
9. Additional features of Tcl and Tk
10. Extensions and applications
• Part I: The Tcl Language
3. Tcl Language Syntax
1. Scripts, commands, and words
2. Evaluating a command
3. Variable substitution
4. Command substitution
5. Backslash substitution
6. Quoting with double quotes
7. Quoting with braces
8. Comments
9. Normal and exceptional returns
10. More on substitutions
4. Variables
1. Simple variables and the set command
2. Arrays
3. Variable substitution
4. Removing variables: unset
5. Multidimensional arrays
6. The incr and append commands
7. Predefined variables
8. Preview of other variable facilities
5. Expressions
1. Numeric operands
2. Operators and precedence
3. Math functions
4. Substitutions
5. String manipulation
6. Types and conversions
7. Precision
6. Lists
1. Basic list structure and the lindex command
2. Creating listss: concat, list, llength
3. Modifying lists: linsert, lreplace, lrange, and lappend
4. Searching lists: lsearch
5. Sorting lists: lsort
6. Converting between strings and lists: split and join
7. Lists and commands
7. Control Flow
1. The if command
2. Looping commands: while, for, and foreach
3. Loop control: break, and continue
4. The switch command
5. The eval command
6. Executing from files: source
8. Procedures
1. Procedure basics: proc and return
2. Local and global variables
3. Defaults and variable numbers of arguments
4. Call by reference: upvar
5. Creating new control structures: uplevel
9. String Manipulation
1. Character set issues
2. Glob-style pattern matching
3. Pattern matching with regular expressions
4. Using regular expressions for substitutions
5. Generating strings with format
6. Parsing strings with scan
7. Extracting characters: string index and string range
8. Searching and comparison
9. Length, case conversion, and trimming
10. Accessing Files
1. File names
2. Basic File I/O
3. Output buffering
4. Random access to files
5. The current working directory
6. Manipulating file names: glob and file
7. File information commands
8. Errors in system calls
11. Processes
1. Invoking subprocesses with exec
2. I/O to and from a command pipeline
3. Process ids
4. Environmt variables
5. Terminating the Tcl process with exit
12. Errors and Exceptions
1. What happens after an error?
2. Generating errors from Tcl scripts
3. Trapping errors with catch
4. Exceptions in general
13. Managing Tcl Internals
1. Querying the elements of an array
2. The info command
3. Timing command execution
4. Tracing operations on variables
5. Renaming and deleting commands
6. Unknown commands
7. Autoloading
14. History
1. The history list
2. Specifying events
3. Reexcuting commands from the history list
4. Shortcuts implemented by unknown
5. Current event number: history nextid
• Part II: Writing Scripts for Tk
15. An Introduction to Tk
1. A brief introduction to X
2. Widgets
3. Applications, top-level widgets, and screens
4. Scripts and events
5. Creating and destroying widgets
6. Geometry managers
7. Widget commands
8. Commands for interconnection
16. A Tour of the Tk Widgets
1. Frames
2. Toplevels
3. Labels
4. Buttons, checkbuttons, and radiobuttons
5. Messages
6. Listboxes
7. Scrollbars
8. Scales
9. Entries
10. Menus and menubuttons
11. Other common options
17. Geometry Managers: The Packer
1. An overview of geometry management
2. Packer basics
3. The pack command and -side options
4. Padding
5. Filling
6. Expansion
7. Anchors
8. Packing order
9. Hierarchical packing
10. Other options to the pack command
11. Other geometry managers in Tk
18. Bindings
1. X Events
2. An overview of the bind command
3. Event patterns
4. Sequences of events
5. Substitutions in scripts
6. Conflict resolution
7. When are events processed?
8. Background errors: tkerror
9. Other uses of bindings
19. Canvas and Text Widgets
1. Canvas basics: items and types
2. Manipulating items with identifiers and tags
3. Bindings
4. Other canvas features
5. Text widgets
6. Text indices and marks
7. Text tags
20. The Selection
1. Selections, retrievals, and targets
2. Locating and clearing the selection
3. Supplying the selection with Tcl scripts
21. The Input Focus
1. Focus model: explicit vs. implicit
2. Setting the input focus
3. Clearing the focus
4. The default focus
5. Shortcuts
22. Window Managers
1. Windows sizes
2. Gridded windows
3. Window positions
4. Window states
5. Decorations
6. Window manager protocols
7. Special handling: transients, groups, and override-redirect
8. Session management
9. A warning about window managers
23. The Send Command
1. Basics
2. Hypertools
3. Application names
4. Security issues
24. Modal Interactions
1. Grabs
2. Keyboard handling during grabs
3. Waiting: the tkwait command
25. More on Configuration Options
1. The option database
2. Option database entries
3. The RESOURCE_MANAGER property and .Xdefaults file
4. Priorities in the option database
5. The option command
6. The configure widget command
26. Odds and Ends
1. Destroying widgets
2. Time delays
3. The update command
4. Information about widgets
5. Raise and lower
6. The tk command: color models
7. Variables managed by Tk
27. Examples
1. A procedure that generates dialog boxes
2. A remote-control application
• Part III: Writing Tcl Applications in C
28. Philosophy
1. C vs. Tcl: primitives
2. Object names
3. Commands: action-oriented vs. object-oriented
4. Representing information
29. Interpreters and Script Evaluation
1. Interpreters
2. A simple Tcl application
3. Other evaluation procedures
4. Deleting interpreters
30. Creating New Tcl Commands
1. Command procedures
2. Registering commands
3. The result protocol
4. Procedures for managing the result
5. ClientData and deletion callbacks
6. Deleting commands
7. How Tcl procedures work
31. Tcl_AppInit and Packages
1. Tcl_appInit
2. Defining packages
32. Parsing
1. Numbers and Booleans
2. Expression evaluation
3. Manipulating lists
33. Exceptions
1. Completion hooks
2. Augmenting the stack trace in errorInfo
3. Setting errorCode
34. Accessing Tcl Variables
1. Naming variables
2. Setting variable values
3. Reading variables
4. Unsetting variables
5. Linking Tcl and C variables
6. Setting and unsetting variable traces
7. Trace callbacks
8. Whole-array traces
9. Multiple traces
10. Unset callbacks
11. Nonexistent variables
12. Querying trace information
35. Hash Tables
1. Keys and values
2. Creating and deleting hash tables
3. Creating entries
4. Finding existing entries
5. Searching
6. Deleting entries
7. Statistics
36. String Utilities
1. Dynamic strings
2. Command completeness
3. String matching
37. POSIX Utilities
1. Tilde expansion
2. Generating messages
3. Creating subprocesses
4. Background processes
• Part IV: Tk's C Interfaces
38. Introduction
1. What's in a widget?
2. The relationship between Tk and Xlib
3. Square.: an example widget
4. tk.h
5. Design for reusability
39. Creating Windows
1. Windows and Tk_Windows
2. Creating Tk_Windows
3. Setting a window's class
4. Deleting a windows
5. Basic operations on Tk_Windows
6. Class command procedures
7. Package initialization
8. Delayed window creation
40. Configuring Widgets
1. Tk_ConfigureWidget
2. Resource caches
3. Tk_Uids
4. Other translators
5. Changing window attributes
6. The square configure procedure
7. The square widget command procedure
41. Events
1. X Events
2. File Events
3. Timer events
4. Idle callbacks
5. Generic event handlers
6. Invoking the event dispatcher
42. Displaying Widgets
1. Delayed redisplay
2. Double-buffering with pixmaps
3. Drawing procedures
43. Destroying Widgets
1. Basics
2. Delayed cleanup
44. Managing the Selection
1. Selecting handlers
2. Claiming the selection
3. Retrieving the selection
45. Geometry Management
1. Requesting a size for a widget
2. Internal borders
3. Grids
4. Geometry managers
5. Claiming ownership
6. Retrieving geometry information
7. Mapping and setting geometry
8. Writing geometry managers

1. Installing Tcl and Tk
1. Versions
2. The master directory
3. Retrieving distributions with FTP
4. Retrieving distributions with electronic mail
5. Compiling and installing the distributions
6. Contributed extensions
7. Comp.lang.tcl newsgroup

The classical text on Tcl/Tk, by its creator.