Rename README.posix-bc to README.bs2000 to avoid confusion

when people think that perlposix-bc.pod tells anything about
Perl and POSIX.  Regen toc.

p4raw-id: //depot/perl@8730

1 files changed, 178 insertions, 0 deletions

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+This document is written in pod format hence there are punctuation
+characters in in odd places.  Do not worry, you've apparently got the
+ASCII->EBCDIC translation worked out correctly.  You can read more
+about pod in pod/perlpod.pod or the short summary in the INSTALL file.
+
+=head1 NAME
+
+README.posix-bc - building and installing Perl for BS2000 POSIX.
+
+=head1 SYNOPSIS
+
+This document will help you Configure, build, test and install Perl
+on BS2000 in the POSIX subsystem.
+
+=head1 DESCRIPTION
+
+This is a ported perl for the POSIX subsystem in BS2000 VERSION OSD
+V3.1A.  It may work on other versions, but that's the one we've tested
+it on.
+
+You may need the following GNU programs in order to install perl:
+
+=head2 gzip
+
+We used version 1.2.4, which could be installed out of the box with
+one failure during 'make check'.
+
+=head2 bison
+
+The yacc coming with BS2000 POSIX didn't work for us.  So we had to
+use bison.  We had to make a few changes to perl in order to use the
+pure (reentrant) parser of bison.  We used version 1.25, but we had to
+add a few changes due to EBCDIC.
+
+=head2 Unpacking
+
+To extract an ASCII tar archive on BS2000 POSIX you need an ASCII
+filesystem (we used the mountpoint /usr/local/ascii for this).  Now
+you extract the archive in the ASCII filesystem without
+I/O-conversion:
+
+cd /usr/local/ascii
+export IO_CONVERSION=NO
+gunzip < /usr/local/src/perl.tar.gz | pax -r
+
+You may ignore the error message for the first element of the archive
+(this doesn't look like a tar archive / skipping to next file...),
+it's only the directory which will be created automatically anyway.
+
+After extracting the archive you copy the whole directory tree to your
+EBCDIC filesystem.  B<This time you use I/O-conversion>:
+
+cd /usr/local/src
+IO_CONVERSION=YES
+cp -r /usr/local/ascii/perl5.005_02 ./
+
+=head2 Compiling
+
+There is a "hints" file for posix-bc that specifies the correct values
+for most things.  The major problem is (of course) the EBCDIC character
+set.  We have german EBCDIC version.
+
+Because of our problems with the native yacc we used GNU bison to
+generate a pure (=reentrant) parser for perly.y.  So our yacc is
+really the following script:
+
+-----8<-----/usr/local/bin/yacc-----8<-----
+#! /usr/bin/sh
+
+# Bison as a reentrant yacc:
+
+# save parameters:
+params=""
+while [[ $# -gt 1 ]]; do
+    params="$params $1"
+    shift
+done
+
+# add flag %pure_parser:
+
+tmpfile=/tmp/bison.$$.y
+echo %pure_parser > $tmpfile
+cat $1 >> $tmpfile
+
+# call bison:
+
+echo "/usr/local/bin/bison --yacc $params $1\t\t\t(Pure Parser)"
+/usr/local/bin/bison --yacc $params $tmpfile
+
+# cleanup:
+
+rm -f $tmpfile
+-----8<----------8<-----
+
+We still use the normal yacc for a2p.y though!!!  We made a softlink
+called byacc to distinguish between the two versions:
+
+ln -s /usr/bin/yacc /usr/local/bin/byacc
+
+We build perl using GNU make.  We tried the native make once and it
+worked too.
+
+=head2 Testing
+
+We still got a few errors during C<make test>.  Some of them are the
+result of using bison.  Bison prints I<parser error> instead of I<syntax
+error>, so we may ignore them.  The following list shows
+our errors, your results may differ:
+
+op/numconvert.......FAILED tests 1409-1440
+op/regexp...........FAILED tests 483, 496
+op/regexp_noamp.....FAILED tests 483, 496
+pragma/overload.....FAILED tests 152-153, 170-171
+pragma/warnings.....FAILED tests 14, 82, 129, 155, 192, 205, 207
+lib/bigfloat........FAILED tests 351-352, 355
+lib/bigfltpm........FAILED tests 354-355, 358
+lib/complex.........FAILED tests 267, 487
+lib/dumper..........FAILED tests 43, 45
+Failed 11/231 test scripts, 95.24% okay. 57/10595 subtests failed, 99.46% okay.
+
+=head2 Install
+
+We have no nroff on BS2000 POSIX (yet), so we ignored any errors while
+installing the documentation.
+
+
+=head2 Using Perl
+
+BS2000 POSIX doesn't support the shebang notation
+(C<#!/usr/local/bin/perl>), so you have to use the following lines
+instead:
+
+: # use perl
+    eval 'exec /usr/local/bin/perl -S $0 ${1+"$@"}'
+        if $running_under_some_shell;
+
+=head2 Floating point anomalies
+
+There appears to be a bug in the floating point implementation on BS2000 POSIX
+systems such that calling int() on the product of a number and a small
+magnitude number is not the same as calling int() on the quotient of
+that number and a large magnitude number.  For example, in the following
+Perl code:
+
+    my $x = 100000.0;
+    my $y = int($x * 1e-5) * 1e5; # '0'
+    my $z = int($x / 1e+5) * 1e5;  # '100000'
+    print "\$y is $y and \$z is $z\n"; # $y is 0 and $z is 100000
+
+Although one would expect the quantities $y and $z to be the same and equal
+to 100000 they will differ and instead will be 0 and 100000 respectively.
+
+=head1 AUTHORS
+
+Thomas Dorner
+
+=head1 SEE ALSO
+
+L<INSTALL>, L<perlport>.
+
+=head2 Mailing list
+
+The Perl Institute (http://www.perl.org/) maintains a perl-mvs mailing
+list of interest to all folks building and/or using perl on EBCDIC
+platforms.  To subscribe, send a message of:
+
+    subscribe perl-mvs
+
+to majordomo@perl.org.
+
+=head1 HISTORY
+
+This document was originally written by Thomas Dorner for the 5.005
+release of Perl.
+
+This document was podified for the 5.6 release of perl 11 July 2000.
+
+=cut