Tcl Distributed Programming (Tcl-DP)
(Version 4.0b2; Dec 10, 1997)
Brian C. Smith, Mike Perham, Tibor Janosi
Department of Computer Science
Cornell University
This directory contains a freely distributable extension to Tcl/Tk
called Tcl Distributed Programming (Tcl-DP). Tcl-DP adds TCP, UDP, and
IP-multicast connection management, remote procedure call (RPC), and
distributed object protocols to Tcl/Tk. A C interface to the RPC
primitives is also provided.
Background
----------
Tcl stands for the Tool Command Language, a freely distributable,
embeddable scripting language package. Tk is an freely distributable
window interface toolkit and widget library implemented by a
collection of new commands added to Tcl. Information about Tcl/Tk is
available from http://www.sunlabs.com/research/tcl. Tcl-DP was
originally developed for Tcl 6.5 and Tk 3.0. Tcl-DP 4.0b2 is compatible
with both Tcl 7.6 and Tcl 8.0 (release versions only).
This distribution contains a loadable module for Tcl 8.0. HTML pages
that describe the commands, and several examples that illustrate how
to use Tcl-DP to build simple distributed applications. This file,
and Tcl-DP source code, is available from
http://www.cs.cornell.edu/Info/Projects/zeno/Projects/Tcl-DP.html
Both source and binary releases are available from this location.
In the examples subdirectory, several sample applications are supplied
that use Tcl-DP. As you can see from the examples, the distributed
programming mechanisms of Tcl-DP are very simple. A dp_RPC command,
for example, sends a Tcl command to a remote process, which evaluates
the command in the destination Tcl interpreter and returns the result
as the value of the dp_RPC command.
New Features in 4.0
-------------------
Tcl-DP 4.0 represents the first major rewrite of the code base since its
beginning. This version is distributed as a loadable module for Tcl 8.0
that adds RPC and several communication protocols (TCP, UDP, IP-multicast,
email, and serial lines) to Tcl. Tcl-DP 4.0 uses the Tcl channel abstraction
for all I/O. DP's RPC layer has been rewritten to work with any DP registered
channel, allowing RPCs to be performed across a normal TCP network,
over a serial link or even via e-mail! DP 4.0 also introduces plug-in
filters that that allow a programmatic filter to be inserted into any
network layer, allowing experimental or secure protocols to be built
easily.
Summary of new features:
* RPC over ANY read/writable non-blocking channel.
* Tcl_Channel drivers for TCP, UDP and IP Multicast protocols.
* Tcl_Channel drivers for serial ports and e-mail (via sendmail).
* Plugin Filter API that can attach to a Channel and manipulate the
incoming/outgoing data (i.e. uuencode/uudecode for email,
sequencing for UDP, etc.)
* Designed from the ground up to be portable and easily extensible
(simple to add your own Channels or filters).
How to compile the Tcl-DP 4.0 source
------------------------------------
On SunOS 4.1, Solaris 2.5, Linux 2.0, HP/UX 9.0:
1) Download the Tcl source and unarchive it into a directory
2) Download the Tcl-DP 4.0 source and unarchive it into the same directory
At this point, Tcl and Tcl-DP should be sibling directories.
3) Make Tcl. See the Tcl documentation on how to do this.
4) Change directory to tcl-dp/unix and type './configure'
5) Type 'make'
6) Assuming all went well, you can test the binary by typing 'make tests'
This step is optional.
7) Please see "How to Install the Tcl-DP 4.0 Binaries" below.
Windows:
NOTE: You must use Microsoft Visual C++!
1) Download the Tcl source and unarchive it into a dir.
2) Download Tcl-DP 4.0 source and unarchive it into the same dir.
At this point, Tcl and Tcl-DP should be in sibling directories.
3) Make Tcl. See the Tcl docs on how to do this.
4) Change directory to tcl-dp/win and copy either "makefile.76" or
"makefile.80" to "makefile", depending on your version of Tcl.
5) Type "nmake" to build Tcl-DP.
6) Assuming all went well, you cam test the binary by typing "nmake
tests". This step is optional.
7) Please see "How to Install the Tcl-DP 4.0 Binaries" below.
How to install the Tcl-DP 4.0 Binaries
--------------------------------------
Tcl-DP uses a homegrown tool to install itself: Teki. Teki is a
Tcl/Tk application that can manage Tcl packages and automatically install
or uninstall them. To install the Tcl-DP binaries, simply run teki.tcl
in wish and select 'File | Install'. Select dp.tek and Teki should
install DP into your Tcl/Tk installation. NOTE: we assume that wish
has been installed correctly on your system.
To use Tcl-DP
-------------
Using Tcl-DP requires nothing more than wish or tclsh. All DP scripts
should have "package require dp" as their first line which will
automatically load the DP module if it has not been loaded already.
Please see the FAQ before emailing us if you have problems using DP.
Documentation
-------------
Documentation for the new DP 4.0 API and library functions is available
in the doc subdirectory in standard HTML format. You can use any WWW
browser to read the files.
Bug Reports
-----------
Send mail to tcl-dp@cs.cornell.edu.
Credits
-------
Tcl-DP 4.0 exists due to the following people:
Brian Smith, Mike Perham, Tibor Janosi, Ioi Lam
We extend our thanks to everyone who helped to create, debug, and
distribute this software. Although there are too many people to mention
at this point, the following people deserve special attention:
John Ousterhout, creator of Tcl/Tk;
Pekka Nikander, creator of tcpConnect;
Tim MacKenzie, creator of tclRawTCP;
Larry Rowe, co-creator of the original Tcl-DP;
Lou Salkind, ported Tcl-DP to Tcl 7.0/Tk 3.3
R Lindsay Todd, developed security mechanism
Peter Liu, developed extended name server code
Ulla Bartsich, integrated many changes into Tcl-DP 3.3
Mike Grafton, wrote extensive test suites for Tcl-DP 3.x
Jon Knight, wrote IP-multicast extensions to Tcl-DP 3.x
Gordon Chaffee, ported Tcl-DP 3 to Windows-NT
