NAME
    README.BS2000 - building and installing Perl for BS2000.

SYNOPSIS
    This document will help you Configure, build, test and install Perl on
    BS2000 in the POSIX subsystem.

DESCRIPTION
    This is a ported perl for the POSIX subsystem in BS2000 VERSION OSD
    V3.1A or later. It may work on other versions, but we started porting
    and testing it with 3.1A and are currently using Version V4.0A.

    You may need the following GNU programs in order to install perl:

    gzip on BS2000

    We used version 1.2.4, which could be installed out of the box with one
    failure during 'make check'.

    bison on BS2000

    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. See below for more details concerning yacc.

    Unpacking Perl Distribution on BS2000

    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. This time you use I/O-conversion:

    cd /usr/local/src IO_CONVERSION=YES cp -r /usr/local/ascii/perl5.005_02
    ./

    Compiling Perl on BS2000

    There is a "hints" file for BS2000 called hints.posix-bc (because
    posix-bc is the OS name given by `uname`) 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 gen-
    erate 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.

    Testing Perl on BS2000

    We still got a few errors during "make test". Some of them are the
    result of using bison. Bison prints parser error instead of 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/over-
    load.....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/com-
    plex.........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.

    Installing Perl on BS2000

    We have no nroff on BS2000 POSIX (yet), so we ignored any errors while
    installing the documentation.

    Using Perl in the Posix-Shell of BS2000

    BS2000 POSIX doesn't support the shebang notation
    ("#!/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;

    Using Perl in "native" BS2000

    We don't have much experience with this yet, but try the following:

    Copy your Perl executable to a BS2000 LLM using bs2cp:

    "bs2cp /usr/local/bin/perl 'bs2:perl(perl,l)'"

    Now you can start it with the following (SDF) command:

    "/START-PROG FROM-FILE=*MODULE(PERL,PERL),PROG-MODE=*ANY,RUN-MODE=*ADV"

    First you get the BS2000 commandline prompt ('*'). Here you may enter
    your parameters, e.g. "-e 'print "Hello World!\\n";'" (note the double
    backslash!) or "-w" and the name of your Perl script. Filenames start-
    ing with "/" are searched in the Posix filesystem, others are searched
    in the BS2000 filesystem. You may even use wildcards if you put a "%"
    in front of your filename (e.g. "-w checkfiles.pl %*.c"). Read your
    C/C++ manual for additional possibilities of the commandline prompt
    (look for PARAMETER-PROMPTING).

    Floating point anomalies on BS2000

    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.

AUTHORS
    Thomas Dorner

SEE ALSO
    INSTALL, perlport.

    Mailing list

    If you are interested in the VM/ESA, z/OS (formerly known as OS/390)
    and POSIX-BC (BS2000) ports of Perl then see the perl-mvs mailing list.
    To subscribe, send an empty message to perl-mvs-subscribe@perl.org.

    See also:

   http://lists.perl.org/showlist.cgi?name=perl-mvs

    There are web archives of the mailing list at:

   http://www.xray.mpe.mpg.de/mailing-lists/perl-mvs/
   http://archive.develooper.com/perl-mvs@perl.org/

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.