This is the directory where you configure, compile, test, and install
UNIX versions of Tcl.  This directory also contains source files for Tcl
that are specific to UNIX.  Some of the files in this directory are
used on the PC or Mac platform too, but they all depend on UNIX
(POSIX/ANSI C) interfaces and some of them only make sense under UNIX.

The rest of this file contains instructions on how to do this.  The
release should compile and run either "out of the box" or with trivial
changes on any UNIX-like system that approximates POSIX, BSD, or System
V.  We know that it runs on workstations from Sun, H-P, DEC, IBM, and
SGI, as well as PCs running Linux, BSDI, and SCO UNIX.  To compile for
a PC running Windows, see the README file in the directory ../win.  To
compile for a Macintosh, see the README file in the directory ../mac.

SCCS: @(#) README 1.13 96/07/31 16:28:38

How To Compile And Install Tcl:
-------------------------------

(a) Check for patches as described in ../README.

(b) If you have already compiled Tcl once in this directory and are now
    preparing to compile again in the same directory but for a different
    platform, or if you have applied patches, type "make distclean" to
    discard all the configuration information computed previously.

(c) Type "./configure".  This runs a configuration script created by GNU
    autoconf, which configures Tcl for your system and creates a
    Makefile.  The configure script allows you to customize the Tcl
    configuration for your site; for details on how you can do this,
    type "./configure -help" or refer to the autoconf documentation (not
    included here).  Tcl's "configure" supports the following special
    switches in addition to the standard ones:
	--enable-gcc		If this switch is set, Tcl will configure
				itself to use gcc if it is available on your
				system.  Note:  it is not safe to modify the
				Makefile to use gcc after configure is run;
				if you do this, then information related to
				dynamic linking will be incorrect.
	--disable-load		If this switch is specified then Tcl will
				configure itself not to allow dynamic loading,
				even if your system appears to support it.
				Normally you can leave this switch out and
				Tcl will build itself for dynamic loading
				if your system supports it.
	--enable-shared		If this switch is specified, Tcl will compile
				itself as a shared library if it can figure
				out how to do that on this platform.
    Note: be sure to use only absolute path names (those starting with "/")
    in the --prefix and --exec_prefix options.

(d) Type "make".  This will create a library archive called "libtcl.a"
    or "libtcl.so" and an interpreter application called "tclsh" that
    allows you to type Tcl commands interactively or execute script files.

(e) If the make fails then you'll have to personalize the Makefile
    for your site or possibly modify the distribution in other ways.
    First check the file "porting.notes" to see if there are hints
    for compiling on your system.  Then look at the porting Web page
    described later in this file.  If you need to modify Makefile, there
    are comments at the beginning of it that describe the things you
    might want to change and how to change them.

(f) Type "make install" to install Tcl binaries and script files in
    standard places.  You'll need write permission on the installation
    directories to do this.  The installation directories are
    determined by the "configure" script and may be specified with
    the --prefix and --exec_prefix options to "configure".  See the
    Makefile for information on what directories were chosen; you
    can override these choices by modifying the "prefix" and
    "exec_prefix" variables in the Makefile.

(g) At this point you can play with Tcl by invoking the "tclsh"
    program and typing Tcl commands.  However, if you haven't installed
    Tcl then you'll first need to set your TCL_LIBRARY variable to
    hold the full path name of the "library" subdirectory.  Note that
    the installed versions of tclsh, libtcl.a, and libtcl.so have a
    version number in their names, such as "tclsh7.5" or "libtcl7.5.so";
    to use the installed versions, either specify the version number
    or create a symbolic link (e.g. from "tclsh" to "tclsh7.5").

If you have trouble compiling Tcl, read through the file" porting.notes".
It contains information that people have provided about changes they had
to make to compile Tcl in various environments.  Or, check out the
following Web URL:
    http://www.sunlabs.com/cgi-bin/tcl/info.4.1
This is an on-line database of porting information.  We make no guarantees
that this information is accurate, complete, or up-to-date, but you may
find it useful.  If you get Tcl running on a new configuration, we would
be happy to receive new information to add to "porting.notes".  You can
also make a new entry into the on-line Web database.  We're also interested
in hearing how to change the configuration setup so that Tcl compiles out
of the box on more platforms.

Test suite
----------

There is a relatively complete test suite for all of the Tcl core in
the subdirectory "tests".  To use it just type "make test" in this
directory.  You should then see a printout of the test files processed.
If any errors occur, you'll see a much more substantial printout for
each error.  See the README file in the "tests" directory for more
information on the test suite.  Note: don't run the tests as superuser:
this will cause several of them to fail.

The Tcl test suite is very sensitive to proper implementation of
ANSI C library procedures such as sprintf and sscanf.  If the test
suite generates errors, most likely they are due to non-conformance
of your system's ANSI C library;  such problems are unlikely to
affect any real applications so it's probably safe to ignore them.
