pad.c: flags checking for the UTF8 flag when necessary

[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

perlvos - 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.  This version of
Perl is not supported on VOS Release 14.2 or earlier releases.  If you
have a Continuum platform running VOS Release 14.3 through 14.7,
download Perl from the Stratus Anonymous FTP site at
ftp://ftp.stratus.com/pub/vos/posix/ga/continuum/continuum.html.  If
you have a V Series platform running VOS Release 15.0 or later, or if
you have a V Series platform running OpenVOS Release 17.0 or later,
download Perl from
ftp://ftp.stratus.com/pub/vos/posix/ga/v-series/v-series.html.  The
perl distribution files on the Stratus anonymous FTP site are stored
in a format called a "bundled file".  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
(or later) of the VOS GNU C/C++ and GNU Tools product from
Stratus Technologies.

=head1 BUILDING PERL FOR VOS

To build perl from its source code on the Stratus Continuum
platform, you must be have VOS Release 14.5.0 or later, the STCP
product, and the GNU C/C++ and GNU Tools, Release 2.0.1 or
later.  On the V Series platform you must have VOS Release
15.0.0 or later, and any version of the GNU C/C++ and GNU Tools
product.

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.

=head1 INSTALLING PERL IN VOS

=over 4

=item 1

If you have built perl using the Configure script, ensure that
you have modify and default write permission to C<<
>system>ported >> and all subdirectories.  Then 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 (replace the string VERSION by the
appropriate version number):

     >system>ported>lib>perl5>VERSION>7100
     >system>ported>lib>perl5>VERSION>8000
     >system>ported>lib>perl5>VERSION>i786

=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>VERSION

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

     >system>ported>lib>perl5>site_perl>VERSION>7100
     >system>ported>lib>perl5>site_perl>VERSION>8000
     >system>ported>lib>perl5>site_perl>VERSION>i786

=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 or later, the VOS POSIX runtime sets up
the PA-RISC and IA-32 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 has
been fixed in VOS Release 15.2 and higher.

=head1 TEST STATUS

When Perl 5.9.0 is built using the native build process on VOS
Release 14.7.0 and GNU C++/GNU Tools 2.0.2a, all but nine
attempted tests either pass or result in TODO (ignored)
failures.  The tests that fail are:

t/io/dup, test 2
t/io/tell, test 28
t/op/pack, test 0
ext/B/t/bytecode, test 1
ext/Devel/Peek/t/Peek, test 1
ext/Encode/t/enc_module, test 1
ext/IO/t/io_dup, test 2
lib/ExtUtils/t/MM_Unix, test 94
lib/Net/ing/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/C++ and GNU Tools Release 2.0.1 (or later) 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

October 6, 2010

=cut