perl/README.bs2000
<<
>>
Prefs
   1This document is written in pod format hence there are punctuation
   2characters in odd places.  Do not worry, you've apparently got the
   3ASCII->EBCDIC translation worked out correctly.  You can read more
   4about pod in pod/perlpod.pod or the short summary in the INSTALL file.
   5
   6=head1 NAME
   7
   8README.BS2000 - building and installing Perl for BS2000.
   9
  10=head1 SYNOPSIS
  11
  12This document will help you Configure, build, test and install Perl
  13on BS2000 in the POSIX subsystem.
  14
  15=head1 DESCRIPTION
  16
  17This is a ported perl for the POSIX subsystem in BS2000 VERSION OSD
  18V3.1A or later.  It may work on other versions, but we started porting
  19and testing it with 3.1A and are currently using Version V4.0A.
  20
  21You may need the following GNU programs in order to install perl:
  22
  23=head2 gzip on BS2000
  24
  25We used version 1.2.4, which could be installed out of the box with
  26one failure during 'make check'.
  27
  28=head2 bison on BS2000
  29
  30The yacc coming with BS2000 POSIX didn't work for us.  So we had to
  31use bison.  We had to make a few changes to perl in order to use the
  32pure (reentrant) parser of bison.  We used version 1.25, but we had to
  33add a few changes due to EBCDIC.  See below for more details
  34concerning yacc.
  35
  36=head2 Unpacking Perl Distribution on BS2000
  37
  38To extract an ASCII tar archive on BS2000 POSIX you need an ASCII
  39filesystem (we used the mountpoint /usr/local/ascii for this).  Now
  40you extract the archive in the ASCII filesystem without
  41I/O-conversion:
  42
  43cd /usr/local/ascii
  44export IO_CONVERSION=NO
  45gunzip < /usr/local/src/perl.tar.gz | pax -r
  46
  47You may ignore the error message for the first element of the archive
  48(this doesn't look like a tar archive / skipping to next file...),
  49it's only the directory which will be created automatically anyway.
  50
  51After extracting the archive you copy the whole directory tree to your
  52EBCDIC filesystem.  B<This time you use I/O-conversion>:
  53
  54cd /usr/local/src
  55IO_CONVERSION=YES
  56cp -r /usr/local/ascii/perl5.005_02 ./
  57
  58=head2 Compiling Perl on BS2000
  59
  60There is a "hints" file for BS2000 called hints.posix-bc (because
  61posix-bc is the OS name given by `uname`) that specifies the correct
  62values for most things.  The major problem is (of course) the EBCDIC
  63character set.  We have german EBCDIC version.
  64
  65Because of our problems with the native yacc we used GNU bison to
  66generate a pure (=reentrant) parser for perly.y.  So our yacc is
  67really the following script:
  68
  69-----8<-----/usr/local/bin/yacc-----8<-----
  70#! /usr/bin/sh
  71
  72# Bison as a reentrant yacc:
  73
  74# save parameters:
  75params=""
  76while [[ $# -gt 1 ]]; do
  77    params="$params $1"
  78    shift
  79done
  80
  81# add flag %pure_parser:
  82
  83tmpfile=/tmp/bison.$$.y
  84echo %pure_parser > $tmpfile
  85cat $1 >> $tmpfile
  86
  87# call bison:
  88
  89echo "/usr/local/bin/bison --yacc $params $1\t\t\t(Pure Parser)"
  90/usr/local/bin/bison --yacc $params $tmpfile
  91
  92# cleanup:
  93
  94rm -f $tmpfile
  95-----8<----------8<-----
  96
  97We still use the normal yacc for a2p.y though!!!  We made a softlink
  98called byacc to distinguish between the two versions:
  99
 100ln -s /usr/bin/yacc /usr/local/bin/byacc
 101
 102We build perl using GNU make.  We tried the native make once and it
 103worked too.
 104
 105=head2 Testing Perl on BS2000
 106
 107We still got a few errors during C<make test>.  Some of them are the
 108result of using bison.  Bison prints I<parser error> instead of I<syntax
 109error>, so we may ignore them.  The following list shows
 110our errors, your results may differ:
 111
 112op/numconvert.......FAILED tests 1409-1440
 113op/regexp...........FAILED tests 483, 496
 114op/regexp_noamp.....FAILED tests 483, 496
 115pragma/overload.....FAILED tests 152-153, 170-171
 116pragma/warnings.....FAILED tests 14, 82, 129, 155, 192, 205, 207
 117lib/bigfloat........FAILED tests 351-352, 355
 118lib/bigfltpm........FAILED tests 354-355, 358
 119lib/complex.........FAILED tests 267, 487
 120lib/dumper..........FAILED tests 43, 45
 121Failed 11/231 test scripts, 95.24% okay. 57/10595 subtests failed, 99.46% okay.
 122
 123=head2 Installing Perl on BS2000
 124
 125We have no nroff on BS2000 POSIX (yet), so we ignored any errors while
 126installing the documentation.
 127
 128
 129=head2 Using Perl in the Posix-Shell of BS2000
 130
 131BS2000 POSIX doesn't support the shebang notation
 132(C<#!/usr/local/bin/perl>), so you have to use the following lines
 133instead:
 134
 135: # use perl
 136    eval 'exec /usr/local/bin/perl -S $0 ${1+"$@"}'
 137        if $running_under_some_shell;
 138
 139=head2 Using Perl in "native" BS2000
 140
 141We don't have much experience with this yet, but try the following:
 142
 143Copy your Perl executable to a BS2000 LLM using bs2cp:
 144
 145C<bs2cp /usr/local/bin/perl 'bs2:perl(perl,l)'>
 146
 147Now you can start it with the following (SDF) command:
 148
 149C</START-PROG FROM-FILE=*MODULE(PERL,PERL),PROG-MODE=*ANY,RUN-MODE=*ADV>
 150
 151First you get the BS2000 commandline prompt ('*').  Here you may enter
 152your parameters, e.g. C<-e 'print "Hello World!\\n";'> (note the
 153double backslash!) or C<-w> and the name of your Perl script.
 154Filenames starting with C</> are searched in the Posix filesystem,
 155others are searched in the BS2000 filesystem.  You may even use
 156wildcards if you put a C<%> in front of your filename (e.g. C<-w
 157checkfiles.pl %*.c>).  Read your C/C++ manual for additional
 158possibilities of the commandline prompt (look for
 159PARAMETER-PROMPTING).
 160
 161=head2 Floating point anomalies on BS2000
 162
 163There appears to be a bug in the floating point implementation on BS2000 POSIX
 164systems such that calling int() on the product of a number and a small
 165magnitude number is not the same as calling int() on the quotient of
 166that number and a large magnitude number.  For example, in the following
 167Perl code:
 168
 169    my $x = 100000.0;
 170    my $y = int($x * 1e-5) * 1e5; # '0'
 171    my $z = int($x / 1e+5) * 1e5;  # '100000'
 172    print "\$y is $y and \$z is $z\n"; # $y is 0 and $z is 100000
 173
 174Although one would expect the quantities $y and $z to be the same and equal
 175to 100000 they will differ and instead will be 0 and 100000 respectively.
 176
 177=head2 Using PerlIO and different encodings on ASCII and EBCDIC partitions
 178
 179Since version 5.8 Perl uses the new PerlIO on BS2000.  This enables
 180you using different encodings per IO channel.  For example you may use
 181
 182    use Encode;
 183    open($f, ">:encoding(ascii)", "test.ascii");
 184    print $f "Hello World!\n";
 185    open($f, ">:encoding(posix-bc)", "test.ebcdic");
 186    print $f "Hello World!\n";
 187    open($f, ">:encoding(latin1)", "test.latin1");
 188    print $f "Hello World!\n";
 189    open($f, ">:encoding(utf8)", "test.utf8");
 190    print $f "Hello World!\n";
 191
 192to get two files containing "Hello World!\n" in ASCII, EBCDIC, ISO
 193Latin-1 (in this example identical to ASCII) respective UTF-EBCDIC (in
 194this example identical to normal EBCDIC).  See the documentation of
 195Encode::PerlIO for details.
 196
 197As the PerlIO layer uses raw IO internally, all this totally ignores
 198the type of your filesystem (ASCII or EBCDIC) and the IO_CONVERSION
 199environment variable.  If you want to get the old behavior, that the
 200BS2000 IO functions determine conversion depending on the filesystem
 201PerlIO still is your friend.  You use IO_CONVERSION as usual and tell
 202Perl, that it should use the native IO layer:
 203
 204    export IO_CONVERSION=YES
 205    export PERLIO=stdio
 206
 207Now your IO would be ASCII on ASCII partitions and EBCDIC on EBCDIC
 208partitions.  See the documentation of PerlIO (without C<Encode::>!)
 209for further posibilities.
 210
 211=head1 AUTHORS
 212
 213Thomas Dorner
 214
 215=head1 SEE ALSO
 216
 217L<INSTALL>, L<perlport>.
 218
 219=head2 Mailing list
 220
 221If you are interested in the VM/ESA, z/OS (formerly known as OS/390)
 222and POSIX-BC (BS2000) ports of Perl then see the perl-mvs mailing list.
 223To subscribe, send an empty message to perl-mvs-subscribe@perl.org.
 224
 225See also:
 226
 227    http://lists.perl.org/showlist.cgi?name=perl-mvs
 228
 229There are web archives of the mailing list at:
 230
 231    http://www.xray.mpe.mpg.de/mailing-lists/perl-mvs/
 232    http://archive.develooper.com/perl-mvs@perl.org/
 233
 234=head1 HISTORY
 235
 236This document was originally written by Thomas Dorner for the 5.005
 237release of Perl.
 238
 239This document was podified for the 5.6 release of perl 11 July 2000.
 240
 241=cut
 242
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.