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              *** README.EXTD - README file for Extended Tcl ***


EXTENDED TCL
============

    Extended Tcl (TclX), defines a set of extensions to Tcl 6.4, the Tool
Command Language invented by Dr. John Ousterhout of the University of
California at Berkeley.  Tcl is a powerful, yet simple embeddable programming
language.  Extended Tcl is oriented towards system programming tasks, with
many additional interfaces to the Unix operating system, It is upwardly
compatible with Tcl 6.4.  You take the Extended Tcl package, add it to Tcl
6.4, and from that you get Extended Tcl.  (Berkeley Tcl is not included in
this distribution, obtain it from sprite.berkeley.edu).

   Support is also included for building a Tk wish shell with the Extended Tcl
command set.

    Extended Tcl was designed and implemented by Karl Lehenbauer
(karl@NeoSoft.com) and Mark Diekhans (markd@Grizzly.com), with help in the
early stages from Peter da Silva (peter@NeoSoft.com).

   As with Berkeley Tcl, all of Extended Tcl is freely redistributable,
including for commercial use and resale.


FEATURES ADDED BY EXTENDED TCL
==============================

   Here is a summary of the features added by Extended Tcl.  For more details
on the commands and functionality provided by Extended Tcl, see the manual
page man/TclX.man.

    o A shell, which provides an environment for developing and executing
      Tcl programs.  

    o Advanced Tcl code library facility.

    o General purpose commands which define new programming constructs,
      debugging and profiling facilities.

    o Unix access commands provide access to many Unix system calls, including
      process management.

    o File I/O commands provided added facilities for accessing and
      manipulating open files.

    o File scanning facility that provides awk-like functionality.

    o Math commands (random, sin, cos, etc).

    o Extended list manipulation commands

    o Keyed lists, a type of list that provided functionality similar to C
      structures.

    o Extended string and character manipulation commands.


NEW FEATURES IN THIS RELEASE
============================

    o All known bugs are fixed.

    o Configuration has been simplified.

    o Improved support for Tk.  Including building a wish with signal support
      and building a Tk package library.

    o All floating point functions (sin, cos, etc).  Now take expressions
      as arguments.  Floating point numbers will not be demoted to integers
      or lose precision.

    o The standard Tcl expr command is patched so that floating point numbers
      do not get demoted to integers or lose precision.  This patch has been
      submitted to John Ousterhout.

    o The character string manipulation commands take integer expressions
      for positions and lengths.

    o The performance of the loading of package library indices and the
      loading of packages from the libraries has been improved.

    o A performance profiling facility has been added.

    o The alarm command will take fractions of a second on systems with the
      setitimer system call.

    o Fcntl and fstat are easier to use.

    o Better signal handling on systems with Posix signals.

    o And more.  Review "TclX.man" and "CHANGES" for full details.

ON-LINE HELP
============

    There is a help system included with Extended Tcl.  It contains some
documentation on every command in Berkeley Tcl, and Extended Tcl.  You can
invoke it interactively from within Extended Tcl by typing "help".

    Once you bring Tcl up and have gotten it to pass all the tests, try typing
"help help" to learn how to use help.

MANUAL PAGES
============

    Man pages in nroff/troff format are provided for all of Tcl and the
extensions in the directory tclX6.4c/man.  Start with the TclX.man manual.

EXTENDED TCL VERSION NAMING
===========================

    Extended Tcl takes its version number from the corresponding version of
Berkeley (Ousterhout) Tcl upon which it is based, with the addition of a
trailing letter in case there are multiple releases of Extended Tcl within a
single release of Berkeley Tcl.  This release is TclX 6.4c.

INTERFACING TCL AND C++
=======================

C++ programmers can include the file "tcl++.h" to define C++ classes
that can be used to access a Tcl interpreter.  This is based on Tcl
C++ classes originally developed by Parag Patel.

TCL DIRECTORY HIERARCHY
=======================

Here is an overview of the directory hierarchy:

                             top_level_directory

                          tcl6.4    tclX6.4c   tk2.3

The tcl6.4 directory contains Berkeley Tcl, unmodified and tk2.3 contains
unmodified tk2.3, if you plan to use Tk  These locations are only suggested,
they maybe changed by editing tclX6.4c/Config.mk.

The following directories are included under the tclX6.4c directory:

    o config - Configuration files for various Unix versions.

    o man - Unformated manual pages for TclX.

    o src - The main source for TclX.

    o osSupport - Library routines required by TclX that may not be available
      on all Unix versions. 

    o ucbsrc - A makefile and sed scripts used to modify source files that
      are supplied with UCB Tcl.  The files are modified with sed so you don't
      have to have patch to build Tcl, however context diffs are provided if
      problems occur porting to a new version of Tcl.

    o tclsrc - Tcl source that is built into the Tcl package library.

    o tcllib - Tcl source and runtime environment that is required to run TclX.

    o tcllib/help - Help files for Tcl and TclX.

    o tests - Tests for TclX.

    o tkucbsrc - A makefile and sed scripts used to modify source files that
      are supplied with Tk to add in TclX functionality.  Context diffs are
      also provided.

    o tksrc - A makefile that builds a version of the Tk wish shell containing
      Extended Tcl.

    o experimental - An directory of expermintal and contributed Tcl source.
      The code is not normally built as part of TclX.

HOW TO BUILD IT
===============

   Please read TclX.man in the tclX6.4c/man directory before starting the
engine or working under the hood.

    Configure and build Berkeley Tcl as described in that distribution.  Don't
forget to do a "csh config" before running make for the first time.

    Cd to the "tclX6.4c" directory, which contains this distribution.  Edit the
file "Config.mk" to configure Extended Tcl for your Unix version and your
preferences.  The first part of this file contains user preference options,
including the location of the Berkeley Tcl source and, optionally, the Tk 2.3
source.  A macro TCL_CONFIG_FILE is also defined that points to a Unix system
configuration file in the "config" directory.  There should be one there for
your system.  If not, you will have to develop one based on the documentation
in "Config.mk".  If you develop or fix problems in a configuration file,
please send it to us at the address below.

    Now do a "make".  If all goes well, this will augment the tcl.a library
will all of the functions defined by both Berkeley and Extended Tcl, and
create an executable version of tcl in the "tclX6.4c" directory called, simply
enough, "tcl".  A "wish" executable will be also built if it was requested.

    Until the Extended Tcl runtime files are installed, "tcl" and "wish" can't
be run directly.  To run them before installation, use "runtcl" or "runwish".

    Next enter the command "runtcl" and, if everything worked, you should be
greeted by a tcl prompt:

tcl>

   Note that until Extended Tcl is installed, it will only run while in the
tclX6.4c directory.

RUN TESTS TO INSURE THAT TCL IS WORKING PROPERLY
================================================

    Tcl and TclX come with over 1400 tests that you can run to insure that it
is working properly.  These tests have greatly helped us while working on Tcl
by detecting bugs that get introduced accidentally as side-effects of changes.
Consequently, we have found Tcl to be very reliable, and have had very few
cases where a new release has regressed by introducing new bugs in old
functions, or reintroducing old bugs in old functions.

   There are two sets of tests: the tests from Berkeley Tcl, and tests for
Extended Tcl, which test both the new commands added by Extended Tcl and the
procedures defined in the Tcl procedure library.

    Run both the Berkeley and TclX tests by typing "make test" in the Extended
directory.

    If a test fails, please dig into the test and the C source for the function
being tested, fix the bug and mail us the change.  If you're not inclined to
do this, please report the problem, including the output of the test, to
tcl-project@neosoft.com.  Sometimes tests fail due to problems in the system
environment or bugs in that test rather than problems with TclX.  Even if a few
of the tests fail, you probably still have a working TclX.

   If you're having trouble with the Berkeley tests, and you suspect that the
extensions might be involved, you can build a special minimal version of
Berkeley Tcl by cd'ing to the tcl6.4 directory and doing a "make tclTest".
You can then invoke "tclTest", where you should be greeted by a "%" prompt.
Next, cd to the tests directory and do a "source all".

    Note that the Berkeley tests turn off tcl's ability to autoload procedures
from the Tcl source library, so after running the tests, you should usually
exit Tcl and restart it.

INSTALLING EXTENDED TCL
=======================

    To install Extended Tcl, edit the tclX6.4c/Config.mk installation
configuration section to match your preferences. Read the information in the
Makefile carefully before configuring it. Cd to the tclX6.4c directory and do
a "make install" (normally as root).  This will install include files and
manual pages for Berkeley Tcl and TclX, as well as the TclX binary and
library.

    The Tcl default file may be used to install more than one version of
TclX on a system.

MAKING EXECUTABLE TCL SCRIPTS
=============================

    It is common to want to write Tcl scripts, put them in a directory along
your search path, and execute them just like you do with shell scripts.

On systems that support the "#!" convention, you can put a

#!/usr/local/bin/tcl

as the first line of your script, and executing the script will
automatically invoke tcl to process it.  Of course if you install
Tcl somewhere else, you'll use a different path.

    For systems that don't support this convention (most System V
systems, for example), it is probably best to create a shell
script that does something like:

        exec tcl commandfile.tcl


PACKAGE LIBRARIES
=================

    Package Libraries are a Tcl source code management tool included in
this release.  Package libraries allow you to group Tcl procedures into
logical bundles and create single files, libraries, that contain multiple
packages.  The package code provides a low-overhead means of automatically
demand-loading a package on the first attempt to execute one of the procedures
defined within it.  As such, package libraries provide a mechanism to
accommodate the creation of Tcl applications and libraries of a substantial
size.

SUPPORT FOR EXTENDED TCL
========================

    We are committed to providing continuing support for Extended Tcl.  Please
send questions, bug reports, and bug fixes to:

         tcl-project@NeoSoft.com (uupsi!sugar!tcl-project)

Or leave a note on our BBS at (713) 684-5900

SEND US YOUR LIBRARY ROUTINES
=============================

    If you write a useful Tcl procedure and would like to share it with
everyone, send us a copy and we'll consider it for the Tcl library!

COMPATIBILITY WITH TCLX 6.2b
============================

   We have attempted to main backwards-compatibility with older versions
of TclX.  A few changes were made to enhance usability or fix problems that
have introduced a few incompatibilities, these are listed below.  Remember
that multiple versions of Tcl may be installed on a system using the Tcl
default file.  This is useful when converting applications to the new version.

    o The "wait" command only takes one pid.  This is in anticipation of
      supporting full waitpid functionallity in the wait command.  This will
      be available as soon as it is supported in UCB Tcl.

    o The -i flag has been dropped from the "chmod" command.  It now assumes
      that the number is decimal unless prefixed by a 0.

    o The "fcntl" command has been changed to use Posix defined flag names.
      NDELAY has been renamed NONBLOCK and CLEXEC is now CLOEXEC.  The command
      no longer returns a list of current values, instead individule values
      may be queried.
  
    o The format of the data returned by "signal get" has changed.  Enough
      information is now returned to be able to reset signals.

    o The "fstat" command has changed to make it easier to get single values,
      consequently the syntax to return stat data in an array has changed.

    o A parameter has been added to the Tcl_GetKeyedListKeys C function.

    o The format of package library index files (.tndx) has changed.  These
      should be purged and rebuilt.

    o Added an options argument to Tcl_Startup.  It is not currrently used.


CAVEATS
=======

    Although Extended Tcl compiles and executes the tests properly on SCO Unix
System V/3.2.4, Xenix System V/386, and SunOS, it has not had much use under
Xenix System V/386.

comp    Previous versions of Extended Tcl have also run under Berkeley BSD, HP-UX
and Xenix/286.  This release, however, has not been tested on these machines,
although there is configuration information in the makefile for BSD and HP-UX,
and Extended Tcl should come up fairly easily on these machines.

    Do not create any set-user-id versions of Tcl yet.  There are holes in
the startup sequence involving shell variables and default files that need
to be plugged first.

MAILING LISTS AND NEWSGROUPS FOR TCL
====================================

    A Usenet newsgroup, comp.lang.tcl, is dedicated to discussing Tcl, Tk and
the applications that embed it.

WHERE TO GET IT
===============

Tcl 6.4 is available via anonymous ftp from:

   sprite.berkeley.edu:tcl/tcl6.4.tar.Z
or
   ftp.uu.net:languages/tcl/tcl6.4.tar.Z

Extended Tcl 6.4c can be downloaded by anonymous FTP from:

   sprite.berkeley.edu:tcl/tclX6.4c.tar.Z
or
   barkley.berkeley.edu:tcl/extensions/tclX6.4c.tar.Z
or
   ftp.uu.net:languages/tcl/tclX6.4c.tar.Z

A contributed sources archive resides on barkley.berkeley.edu.