perlport.pod

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The Cygwin environment for Win32; F<README.cygwin> (installed 
as L<perlcygwin>), http://www.cygwin.com/

=item *

The U/WIN environment for Win32,
http://www.research.att.com/sw/tools/uwin/

=item *

Build instructions for OS/2, L<perlos2>

=back

=head2 S<Mac OS>

Any module requiring XS compilation is right out for most people, because
MacPerl is built using non-free (and non-cheap!) compilers.  Some XS
modules that can work with MacPerl are built and distributed in binary
form on CPAN.

Directories are specified as:

    volume:folder:file              for absolute pathnames
    volume:folder:                  for absolute pathnames
    :folder:file                    for relative pathnames
    :folder:                        for relative pathnames
    :file                           for relative pathnames
    file                            for relative pathnames

Files are stored in the directory in alphabetical order.  Filenames are
limited to 31 characters, and may include any character except for
null and C<:>, which is reserved as the path separator.

Instead of C<flock>, see C<FSpSetFLock> and C<FSpRstFLock> in the
Mac::Files module, or C<chmod(0444, ...)> and C<chmod(0666, ...)>.

In the MacPerl application, you can't run a program from the command line;
programs that expect C<@ARGV> to be populated can be edited with something
like the following, which brings up a dialog box asking for the command
line arguments.

    if (!@ARGV) {
        @ARGV = split /\s+/, MacPerl::Ask('Arguments?');
    }

A MacPerl script saved as a "droplet" will populate C<@ARGV> with the full
pathnames of the files dropped onto the script.

Mac users can run programs under a type of command line interface
under MPW (Macintosh Programmer's Workshop, a free development
environment from Apple).  MacPerl was first introduced as an MPW
tool, and MPW can be used like a shell:

    perl myscript.plx some arguments

ToolServer is another app from Apple that provides access to MPW tools
from MPW and the MacPerl app, which allows MacPerl programs to use
C<system>, backticks, and piped C<open>.

"S<Mac OS>" is the proper name for the operating system, but the value
in C<$^O> is "MacOS".  To determine architecture, version, or whether
the application or MPW tool version is running, check:

    $is_app    = $MacPerl::Version =~ /App/;
    $is_tool   = $MacPerl::Version =~ /MPW/;
    ($version) = $MacPerl::Version =~ /^(\S+)/;
    $is_ppc    = $MacPerl::Architecture eq 'MacPPC';
    $is_68k    = $MacPerl::Architecture eq 'Mac68K';

S<Mac OS X>, based on NeXT's OpenStep OS, runs MacPerl natively, under the
"Classic" environment.  There is no "Carbon" version of MacPerl to run
under the primary Mac OS X environment.  S<Mac OS X> and its Open Source
version, Darwin, both run Unix perl natively.

Also see:

=over 4

=item *

MacPerl Development, http://dev.macperl.org/ .

=item *

The MacPerl Pages, http://www.macperl.com/ .

=item *

The MacPerl mailing lists, http://lists.perl.org/ .

=item *

MPW, ftp://ftp.apple.com/developer/Tool_Chest/Core_Mac_OS_Tools/

=back

=head2 VMS

Perl on VMS is discussed in L<perlvms> in the perl distribution.

The official name of VMS as of this writing is OpenVMS.

Perl on VMS can accept either VMS- or Unix-style file
specifications as in either of the following:

    $ perl -ne "print if /perl_setup/i" SYS$LOGIN:LOGIN.COM
    $ perl -ne "print if /perl_setup/i" /sys$login/login.com

but not a mixture of both as in:

    $ perl -ne "print if /perl_setup/i" sys$login:/login.com
    Can't open sys$login:/login.com: file specification syntax error

Interacting with Perl from the Digital Command Language (DCL) shell
often requires a different set of quotation marks than Unix shells do.
For example:

    $ perl -e "print ""Hello, world.\n"""
    Hello, world.

There are several ways to wrap your perl scripts in DCL F<.COM> files, if
you are so inclined.  For example:

    $ write sys$output "Hello from DCL!"
    $ if p1 .eqs. ""
    $ then perl -x 'f$environment("PROCEDURE")
    $ else perl -x - 'p1 'p2 'p3 'p4 'p5 'p6 'p7 'p8
    $ deck/dollars="__END__"
    #!/usr/bin/perl

    print "Hello from Perl!\n";

    __END__
    $ endif

Do take care with C<$ ASSIGN/nolog/user SYS$COMMAND: SYS$INPUT> if your
perl-in-DCL script expects to do things like C<< $read = <STDIN>; >>.

The VMS operating system has two filesystems, known as ODS-2 and ODS-5.

For ODS-2, filenames are in the format "name.extension;version".  The
maximum length for filenames is 39 characters, and the maximum length for
extensions is also 39 characters.  Version is a number from 1 to
32767.  Valid characters are C</[A-Z0-9$_-]/>.

The ODS-2 filesystem is case-insensitive and does not preserve case.
Perl simulates this by converting all filenames to lowercase internally.

For ODS-5, filenames may have almost any character in them and can include
Unicode characters.  Characters that could be misinterpreted by the DCL
shell or file parsing utilities need to be prefixed with the C<^>
character, or replaced with hexadecimal characters prefixed with the
C<^> character.  Such prefixing is only needed with the pathnames are
in VMS format in applications.  Programs that can accept the UNIX format
of pathnames do not need the escape characters.  The maximum length for
filenames is 255 characters.  The ODS-5 file system can handle both
a case preserved and a case sensitive mode.

ODS-5 is only available on the OpenVMS for 64 bit platforms.

Support for the extended file specifications is being done as optional
settings to preserve backward compatibility with Perl scripts that
assume the previous VMS limitations.

In general routines on VMS that get a UNIX format file specification
should return it in a UNIX format, and when they get a VMS format
specification they should return a VMS format unless they are documented
to do a conversion.

For routines that generate return a file specification, VMS allows setting
if the C library which Perl is built on if it will be returned in VMS
format or in UNIX format.

With the ODS-2 file system, there is not much difference in syntax of
filenames without paths for VMS or UNIX.  With the extended character
set available with ODS-5 there can be a significant difference.

Because of this, existing Perl scripts written for VMS were sometimes
treating VMS and UNIX filenames interchangeably.  Without the extended
character set enabled, this behavior will mostly be maintained for
backwards compatibility.

When extended characters are enabled with ODS-5, the handling of
UNIX formatted file specifications is to that of a UNIX system.

VMS file specifications without extensions have a trailing dot.  An
equivalent UNIX file specification should not show the trailing dot.

The result of all of this, is that for VMS, for portable scripts, you
can not depend on Perl to present the filenames in lowercase, to be
case sensitive, and that the filenames could be returned in either
UNIX or VMS format.

And if a routine returns a file specification, unless it is intended to
convert it, it should return it in the same format as it found it.

C<readdir> by default has traditionally returned lowercased filenames.
When the ODS-5 support is enabled, it will return the exact case of the
filename on the disk.

Files without extensions have a trailing period on them, so doing a
C<readdir> in the default mode with a file named F<A.;5> will
return F<a.> when VMS is (though that file could be opened with
C<open(FH, 'A')>).

With support for extended file specifications and if C<opendir> was
given a UNIX format directory, a file named F<A.;5> will return F<a>
and optionally in the exact case on the disk.  When C<opendir> is given
a VMS format directory, then C<readdir> should return F<a.>, and
again with the optionally the exact case.

RMS had an eight level limit on directory depths from any rooted logical
(allowing 16 levels overall) prior to VMS 7.2, and even with versions of
VMS on VAX up through 7.3.  Hence C<PERL_ROOT:[LIB.2.3.4.5.6.7.8]> is a
valid directory specification but C<PERL_ROOT:[LIB.2.3.4.5.6.7.8.9]> is
not.  F<Makefile.PL> authors might have to take this into account, but at
least they can refer to the former as C</PERL_ROOT/lib/2/3/4/5/6/7/8/>.

Pumpkings and module integrators can easily see whether files with too many
directory levels have snuck into the core by running the following in the
top-level source directory:

   $ perl -ne "$_=~s/\s+.*//; print if scalar(split /\//) > 8;" < MANIFEST


The VMS::Filespec module, which gets installed as part of the build
process on VMS, is a pure Perl module that can easily be installed on
non-VMS platforms and can be helpful for conversions to and from RMS
native formats.  It is also now the only way that you should check to
see if VMS is in a case sensitive mode.

What C<\n> represents depends on the type of file opened.  It usually
represents C<\012> but it could also be C<\015>, C<\012>, C<\015\012>, 
C<\000>, C<\040>, or nothing depending on the file organization and 
record format.  The VMS::Stdio module provides access to the 
special fopen() requirements of files with unusual attributes on VMS.

TCP/IP stacks are optional on VMS, so socket routines might not be
implemented.  UDP sockets may not be supported.

The TCP/IP library support for all current versions of VMS is dynamically
loaded if present, so even if the routines are configured, they may
return a status indicating that they are not implemented.

The value of C<$^O> on OpenVMS is "VMS".  To determine the architecture
that you are running on without resorting to loading all of C<%Config>
you can examine the content of the C<@INC> array like so:

    if (grep(/VMS_AXP/, @INC)) {
        print "I'm on Alpha!\n";

    } elsif (grep(/VMS_VAX/, @INC)) {
        print "I'm on VAX!\n";

    } elsif (grep(/VMS_IA64/, @INC)) {
        print "I'm on IA64!\n";

    } else {
        print "I'm not so sure about where $^O is...\n";
    }

In general, the significant differences should only be if Perl is running
on VMS_VAX or one of the 64 bit OpenVMS platforms.

On VMS, perl determines the UTC offset from the C<SYS$TIMEZONE_DIFFERENTIAL>
logical name.  Although the VMS epoch began at 17-NOV-1858 00:00:00.00,
calls to C<localtime> are adjusted to count offsets from
01-JAN-1970 00:00:00.00, just like Unix.

Also see:

=over 4

=item *

F<README.vms> (installed as L<README_vms>), L<perlvms>

=item *

vmsperl list, [e-mail]

=item *

vmsperl on the web, http://www.sidhe.org/vmsperl/index.html

=back

=head2 VOS

Perl on VOS is discussed in F<README.vos> in the perl distribution
(installed as L<perlvos>).  Perl on VOS can accept either VOS- or
Unix-style file specifications as in either of the following:

    C<< $ perl -ne "print if /perl_setup/i" >system>notices >>
    C<< $ perl -ne "print if /perl_setup/i" /system/notices >>

or even a mixture of both as in:

    C<< $ perl -ne "print if /perl_setup/i" >system/notices >>

Even though VOS allows the slash character to appear in object
names, because the VOS port of Perl interprets it as a pathname
delimiting character, VOS files, directories, or links whose names
contain a slash character cannot be processed.  Such files must be
renamed before they can be processed by Perl.  Note that VOS limits
file names to 32 or fewer characters.

The value of C<$^O> on VOS is "VOS".  To determine the architecture that
you are running on without resorting to loading all of C<%Config> you
can examine the content of the @INC array like so:

    if ($^O =~ /VOS/) {
        print "I'm on a Stratus box!\n";
    } else {
        print "I'm not on a Stratus box!\n";
        die;