Transcript Tcl and Tk presentation

Tcl and Tk
Michael U. Ang
history and purpose
How it started
• originally intended to be a reusable command
language.
• After implementing several such "quick-anddirty" command languages and experiencing
problems with each one,
• Then decided to concentrate on implementing a
general-purpose, robust command language
that could easily be integrated into new
applications. Thus Tcl (Tool Command
Language) was born.
How it started
• Tcl is used in combination with the Tk ("Tool Kit")
library, a set of commands and procedures that
make it relatively easy to program graphical user
interfaces in Tcl.
What is Tcl?
• developed by John Ousterhout
(OH-stir-howt) at UC Berkeley.
• Tcl stands for “tool command
language”
• interpreted scripting language;
• most commonly used to build
graphical interfaces in conjunction
with Tk.
• everything is text
Cont… What is Tcl?
• Tcl programs are simply scripts consisting of Tcl
commands that are processed by a Tcl
interpreter at run time.
• example use of Tcl: to build a graphical interface
that displays the output of a C command, and/or
controls the parameters to the C command.
Cont… What is Tcl?
• The Tcl interpreter has been ported from UNIX to
DOS, Windows, OS/2, NT, and Macintosh
environments.
• The Tk toolkit has been ported from X Window
to Windows and Macintosh.
What is Tk?
• A graphical toolkit that gives one access to many
of the graphics primitives of the underlying
windowing system, as well as providing access
to many types of widgets, such as buttons,
scrollbars, menus, and text boxes.
• a set of commands and procedures that make it
relatively easy to program graphical user
interfaces in Tcl.
• Tk defines Tcl commands that let you create and
manipulate user interfaces.
What is wish?
• wish is an interpreter that one can use that:
1) interprets Tcl commands, and
2) interprets Tk commands.
• wish provides access to the combined
functionality of Tcl/Tk.
Versions
• Tcl/Tk 8.4.4 is the recent stable release version.
released on July 22, 2003
Tcl/Tk 8.4 • latest stable release of Tcl/Tk
• highly compatible with Tcl 8.3 through Tcl 8.1
• introduces new core widgets, significant
performance enhancements, numerous
command enhancements and improved 64-bit
integer and file system support
Cont… Versions
Tcl/Tk 8.3 • compatible with Tcl 8.2 and Tcl 8.1
• added many new features to Tk based on the
Dash patch and Img patch
•previous stable release, 8.3.5, was released on
Oct 18, 2002
Tcl/Tk 8.2 • updated the build process to the new Tcl
Extension Architecture. The new features are
primarily at the C-level APIs to support new
extensions. There are also new regular
expression C APIs to support Expect.
• eliminated minor bugs left over from the 8.1
release
Cont… Versions
Tcl/Tk 8.1 • was a major overhaul of Tcl/Tk.
• new support for Unicode and internationalized
applications
• adds thread-safety to the C implementation,
and an all new regular expression package that
adds Advanced Regular Expressions
Tcl/Tk 8.0 • one of the widely used release
• added an on-the-fly byte-code compiler
• added improved cross-platform look and feel;
and a menubar facility and a platform-neutral
font naming system
• last patch release was 8.0.5
Looking forward
• Tcl/Tk 9.0 represents the next giant step for core
development. Relatively few new features will be
introduced in 9.0; instead, development will
focus on rationalization and refactorization of the
C API's and Tcl commands, and modularization
of the core itself.
• 9.0 does not currently have a release date.
Important Features
strengths & weaknesses
Features
1. Easy to learn
 Tcl/Tk is a very simple language.
2. Standard syntax
 once users know Tcl, they will be able to issue
commands easily to any Tcl-based application.
3. Graphical user interfaces
 Tcl’s TK toolkit.
4. Cross-platform applications
 the same Tcl script can run on any platform, hence it
provides an excellent management and integration
tool for mixed environments.
Cont… Features
5. Rapid development
 gets their job done faster.
 Development is fast because of the rapid turnaround;
there is no waiting for long compilations
6. Extensible applications/Embedable
 easy to incorporate Tcl into an application
 the Tcl interpreter (a library of C procedures) was
designed to be embedded in a variety of applications.
Cont… Features
7. Flexible integration
 easy to coordinate existing components and
applications so that they work together effectively.
8. BONUS: It's free!
Drawback
• As the application gets larger, Tcl/Tk code becomes
more and more difficult to understand, maintain and
extend.
Tcl Comparison Chart
Features
Speed of use
Rapid development
Flexible, rapid evolution
Great regular expressions
Breadth of
functionality
Easily extensible
Embeddable
Easy GUIs
Internet and Web-enabled
Enterprise usage
Cross platform
Internationalization support
Thread safe
Database access
Tcl
Perl
Python
Java
Script
Visual
Basic
Sample Programs
Hello World
pack [button .b -text "Hello" -command {puts "Hello World!"}]
• This shows a Hello button on the Main window.
• When you click the button the console window
will display the string "Hello World!" on the
console.
• button command creates an instance .b button
called .hello.
• -text string shows the button title.
• -command string is the command responsed to
the button's action.
• pack command layouts the button on the
window.
Scollbar
Applications written in Perl
AOLserver
• is America Online's Open-Source web server.
• a multithreaded, Tcl-enabled web server used for large
scale, dynamic web sites.
AOL's Digital City
• US’s largest and most popular local city resource.
• uses a Tcl interpreter in each of the back-end host
processes that provide services to Digital Citys visitors
• Every Web page in the Digital City network is generated
by an embedded Tcl script.
Cisco’s ATS
(Automated Test System)
• composed of several tools and libraries based on Tcl that
provide support for writing and executing automated test
scripts. Tcl is incorporated in the ATS interpreter to
generate libraries that simplify the task of controlling
remote devices from automated test scripts.
Cygnus's Source-Navigator
• It extracts information from existing C, C++, Tcl, [incr Tcl],
FORTRAN, Cobol, and assembly programs and uses
this information to build project databases.
• Source-Navigator is developed in Tcl, with about 95% of
the code in Tcl and the rest in C.
Url’s and Books
• www.tcl.tk or http://tcl.activestate.com/
-- Main site where you can find the distribution codes,
manual pages and documentations, and other relevant
informations regarding the Tcl/Tk product line.
• http://www.neosoft.com/tcl/
-- Home Page for the Official Tcl/Tk Contributed Sources
Archive!
• http://incrtcl.sourceforge.net/itcl/
-- provides the extra language support needed to build
large Tcl/Tk applications.
-- introduces the notion of objects, which act as building
blocks for an application.
• http://www.activestate.com/Products/ActiveTcl/
-- The industry-standard Tcl distribution for HP-UX, Linux,
Solaris, and Windows.
-- free
• System Requirements for Active Tcl
Windows Systems:
:: x86 architecture only
:: Win2K,ME or XP: No additional req
:: WinNT 4.0, 98: Internet Explorer 5+
:: WinNT 4.0: Service Pack 5+
Linux Systems:
:: IX-86
:: Minimum 2.0 kernel
Solaris
:: sparc architecture only
:: Minimum Solaris 2.6
HP-UX
:: PA-RISC
:: Minimum HP-UX 11
Visual Tcl
• http://vtcl.sourceforge.net/
-- FREEWARE; currently available: Version 1.6.0b2
-- supports UNIX, Windows, Macintosh and AS400
-- written entirely in Tcl/Tk and generates pure Tcl/Tk code
-- originally written by Stewart Allen, but development has
been taken over by Christian Gavin and Damon
Courtney
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Books
• Tcl and the Tk Toolkit,
by John K. Ousterhout
(Addison-Wesley, April
1994)
• Practical Programming
in Tcl and Tk (4th ed), by
Brent Welch, (Prentice
Hall PTR, June 2003)
Cont… Books
• Tcl/Tk: A Developer's
Guide (2nd ed), by Clif
Flynt (Morgan Kaufmann;
May 2003 )
The End