Warn on 'undef $x; $x OP 1' where OP is *=, /=, %=, or **=

[perl5.git] / README

			   Perl Kit, Version 5.0

		       Copyright 1989-1996, Larry Wall
			    All rights reserved.

    This program is free software; you can redistribute it and/or modify
    it under the terms of either:

	a) the GNU General Public License as published by the Free
	Software Foundation; either version 1, or (at your option) any
	later version, or

	b) the "Artistic License" which comes with this Kit.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See either
    the GNU General Public License or the Artistic License for more details.

    You should have received a copy of the Artistic License with this
    Kit, in the file named "Artistic".  If not, I'll be glad to provide one.

    You should also have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

    For those of you that choose to use the GNU General Public License,
    my interpretation of the GNU General Public License is that no Perl
    script falls under the terms of the GPL unless you explicitly put
    said script under the terms of the GPL yourself.  Furthermore, any
    object code linked with perl does not automatically fall under the
    terms of the GPL, provided such object code only adds definitions
    of subroutines and variables, and does not otherwise impair the
    resulting interpreter from executing any standard Perl script.  I
    consider linking in C subroutines in this manner to be the moral
    equivalent of defining subroutines in the Perl language itself.  You
    may sell such an object file as proprietary provided that you provide
    or offer to provide the Perl source, as specified by the GNU General
    Public License.  (This is merely an alternate way of specifying input
    to the program.)  You may also sell a binary produced by the dumping of
    a running Perl script that belongs to you, provided that you provide or
    offer to provide the Perl source as specified by the GPL.  (The
    fact that a Perl interpreter and your code are in the same binary file
    is, in this case, a form of mere aggregation.)  This is my interpretation
    of the GPL.  If you still have concerns or difficulties understanding
    my intent, feel free to contact me.  Of course, the Artistic License
    spells all this out for your protection, so you may prefer to use that.

--------------------------------------------------------------------------

Perl is a language that combines some of the features of C, sed, awk
and shell.  See the manual page for more hype.  There are also two Nutshell
Handbooks published by O'Reilly & Assoc.  See pod/perlbook.pod
for more information.

Please read all the directions below before you proceed any further, and
then follow them carefully.

After you have unpacked your kit, you should have all the files listed
in MANIFEST.

Installation

1) Detailed instructions are in the file INSTALL.  In brief, the
following should work on most systems:
	rm -f config.sh
	sh Configure
	make
	make test
	make install
For most systems, it should be safe to accept all the Configure
defaults.

2) Read the manual entries before running perl.

3) IMPORTANT!  Help save the world!  Communicate any problems and suggested
patches to me, larry@wall.org (Larry Wall), so we can
keep the world in sync.  If you have a problem, there's someone else
out there who either has had or will have the same problem.
It's usually helpful if you send the output of the "myconfig" script
in the main perl directory.

If you've succeeded in compiling perl, the perlbug script in the utils/
subdirectory can be used to help mail in a bug report.

If possible, send in patches such that the patch program will apply them.
Context diffs are the best, then normal diffs.  Don't send ed scripts--
I've probably changed my copy since the version you have.

Watch for perl patches in comp.lang.perl.announce.  Patches will generally
be in a form usable by the patch program.  If you are just now bringing
up perl and aren't sure how many patches there are, write to me and I'll
send any you don't have.  Your current patch level is shown in
patchlevel.h.


Just a personal note:  I want you to know that I create nice things like this
because it pleases the Author of my story.  If this bothers you, then your
notion of Authorship needs some revision.  But you can use perl anyway. :-)

							The author.