The change #20809 opened up a code path that might leave s unset.

[perl5.git] / README.vos

If you read this file _as_is_, just ignore the funny characters you
see. It is written in the POD format (see pod/perlpod.pod) which is
specially designed to be readable as is.

=head1 NAME

README.vos - Perl for Stratus VOS

=head1 SYNOPSIS

This file contains notes for building perl on the Stratus VOS
operating system.  Perl is a scripting or macro language that is
popular on many systems.  See L<perlbook> for a number of good
books on Perl.

These are instructions for building Perl from source.  Most
people can simply download a pre-compiled distribution from the
VOS anonymous FTP site.  This version of Perl is not supported
on VOS Release 14.2.0 or earlier releases.  If you are running
VOS Release 14.3.0 or later, download Perl from
ftp://ftp.stratus.com/pub/vos/posix/ga/ga.html.  Instructions
for unbundling the Perl distribution file are at
ftp://ftp.stratus.com/pub/vos/utility/utility.html.

If you are running VOS Release 14.4.1 or later, you can obtain a
pre-compiled, supported copy of perl by purchasing Release 2.0.1
of the VOS GNU C++ and GNU Tools product from Stratus
Technologies.

=head1 BUILDING PERL FOR VOS

To build perl from its source code, you must have a Continuum
platform running VOS Release 14.5.0 or later, the STCP product,
and the GNU C++ and GNU Tools, Release 2.0.1 or later.

To build full perl using the supplied Configure script and
makefiles, change to the "vos" subdirectory and type the command
"compile_full_perl" or "start_process compile_full_perl".  This
will configure, build, and test perl.  All of the test cases
that are executed should pass.

=head1 INSTALLING PERL IN VOS

=over 4

=item 1

If you have built perl using the Configure script, ensure that
you have modify permission to C<< >system>ported >> and type

     gmake install

=item 2

While there are currently no architecture-specific
extensions or modules distributed with perl, the following
directories can be used to hold such files:

     >system>ported>lib>perl5>5.9.0>68k
     >system>ported>lib>perl5>5.9.0>860
     >system>ported>lib>perl5>5.9.0>7100
     >system>ported>lib>perl5>5.9.0>8000

=item 3

Site-specific perl extensions and modules can be installed in one of
two places.  Put architecture-independent files into:

     >system>ported>lib>perl5>site_perl>5.9.0

Put site-specific architecture-dependent files into one of the
following directories:

     >system>ported>lib>perl5>site_perl>5.9.0>68k
     >system>ported>lib>perl5>site_perl>5.9.0>860
     >system>ported>lib>perl5>site_perl>5.9.0>7100
     >system>ported>lib>perl5>site_perl>5.9.0>8000

=item 4

You can examine the @INC variable from within a perl program
to see the order in which Perl searches these directories.

=back

=head1 USING PERL IN VOS

=head2 Restrictions of Perl on VOS

This port of Perl version 5 to VOS prefers Unix-style,
slash-separated pathnames over VOS-style greater-than-separated
pathnames.  VOS-style pathnames should work in most contexts, but
if you have trouble, replace all greater-than characters by slash
characters.  Because the slash character is used as a pathname
delimiter, Perl cannot process VOS pathnames containing a slash
character in a directory or file name; these must be renamed.

This port of Perl also uses Unix-epoch date values internally.
As long as you are dealing with ASCII character string
representations of dates, this should not be an issue.  The
supported epoch is January 1, 1980 to January 17, 2038.

See the file pod/perlport.pod for more information about the VOS
port of Perl.

=head2 Handling of underflow and overflow

Prior to VOS Release 14.7.0, VOS does not support automatically
mapping overflowed floating-point values to +infinity, nor
automatically mapping underflowed floating-point values to zero,
unlike many other platforms.  The Perl pack function has been
modified to perform such mapping in software on VOS.  Performing
other floating-point computations that underflow or overflow
will probably result in SIGFPE.  Don't push your luck.

As of VOS Release 14.7.0, the VOS POSIX runtime sets up the
PA-RISC hardware floating-point status register so that the
overflow and underflow exceptions do not trap, but instead
automatically convert the result to infinity or zero, as
appropriate.  As of this writing, there are still floating-point
operations that can trap, for example, subtracting two infinite
values.  This is recorded as suggestion posix-1022, which is not
yet fixed.

=head1 TEST STATUS

When Perl 5.8.1 is built using the native build process on VOS
Release 14.5.0 and GNU C++/GNU Tools 2.0.1, all but five
attempted tests either pass or result in TODO (ignored)
failures.  The tests that fail are:

ext/Time/HiRes/HiRes, tests 8, 11, 20, and 21.
lib/Net/Ping/t/450_service, test 8.

=head1 SUPPORT STATUS

I'm offering this port "as is".  You can ask me questions, but I
can't guarantee I'll be able to answer them.  There are some
excellent books available on the Perl language; consult a book
seller.

If you want a supported version of perl for VOS, purchase the VOS
GNU C++ and GNU Tools Release 2.0.1 product from Stratus
Technologies, along with a support contract (or from anyone else
who will sell you support).

=head1 AUTHOR

Paul Green (Paul.Green@stratus.com)

=head1 LAST UPDATE

March 26, 2003

=cut