PERLBS2000(1) Perl Programmers Reference Guide PERLBS2000(1)
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 didnt 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 doesnt look like a tar archive / skipping to next file...), its
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 doesnt 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 dont 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 $z to be the same and
equal to 100000 they will differ and instead will be 0 and 100000
respectively.
Using PerlIO and different encodings on ASCII and EBCDIC partitions
Since version 5.8 Perl uses the new PerlIO on BS2000. This enables you
using different encodings per IO channel. For example you may use
use Encode;
open($f, ">:encoding(ascii)", "test.ascii");
print $f "Hello World!\n";
open($f, ">:encoding(posix-bc)", "test.ebcdic");
print $f "Hello World!\n";
open($f, ">:encoding(latin1)", "test.latin1");
print $f "Hello World!\n";
open($f, ">:encoding(utf8)", "test.utf8");
print $f "Hello World!\n";
to get two files containing "Hello World!\n" in ASCII, EBCDIC, ISO
Latin-1 (in this example identical to ASCII) respective UTF-EBCDIC (in
this example identical to normal EBCDIC). See the documentation of
Encode::PerlIO for details.
As the PerlIO layer uses raw IO internally, all this totally ignores
the type of your filesystem (ASCII or EBCDIC) and the IO_CONVERSION
environment variable. If you want to get the old behavior, that the
BS2000 IO functions determine conversion depending on the filesystem
PerlIO still is your friend. You use IO_CONVERSION as usual and tell
Perl, that it should use the native IO layer:
export IO_CONVERSION=YES
export PERLIO=stdio
Now your IO would be ASCII on ASCII partitions and EBCDIC on EBCDIC
partitions. See the documentation of PerlIO (without "Encode::"!) for
further posibilities.
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.
perl v5.8.8 2008-04-25 PERLBS2000(1)
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