source: trunk/essentials/dev-lang/perl/README.vms@ 3367

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=head1 NAME

README.vms - Configuring, building, testing, and installing perl on VMS

=head1 SYNOPSIS

To configure, build, test, and install perl on VMS:

    @ Configure
    mms
    mms test
    mms install

mmk may be used in place of mms in the last three steps.

=head1 DESCRIPTION

=head2 Important safety tip

The build and install procedures have changed significantly from the 5.004
releases!  Make sure you read the "Configuring the Perl Build", "Building 
Perl", and "Installing Perl" sections of this document before you build or 
install.  Also please note other changes in the current release by having
a look at L<perldelta/VMS>.

Also note that, as of Perl version 5.005 and later, an ANSI C compliant 
compiler is required to build Perl.  VAX C is *not* ANSI compliant, as it 
died a natural death some time before the standard was set.  Therefore 
VAX C will not compile Perl 5.005 or later.  We are sorry about that.

If you are stuck without Compaq (formerly DEC) C consider trying Gnu C
instead, though there have been no recent reports of builds using Gnu C. 
There is minimal support for Compaq C++ but this support is not complete;
if you get it working please write to the vmsperl list (for info see
L</"Mailing Lists">).


=head2 Introduction to Perl on VMS

The VMS port of Perl is as functionally complete as any other Perl port
(and as complete as the ports on some Unix systems). The Perl binaries
provide all the Perl system calls that are either available under VMS or
reasonably emulated. There are some incompatibilities in process handling
(e.g. the fork/exec model for creating subprocesses doesn't do what you
might expect under Unix), mainly because VMS and Unix handle processes and
sub-processes very differently.

There are still some unimplemented system functions, and of course we
could use modules implementing useful VMS system services, so if you'd like
to lend a hand we'd love to have you.  Join the Perl Porting Team Now!

The current sources and build procedures have been tested on a VAX using
DEC C, and on an AXP using DEC C. If you run into problems with
other compilers, please let us know.  (Note: DEC C was renamed to Compaq C
around version 6.2).

There are issues with various versions of DEC C, so if you're not running a
relatively modern version, check the "DEC C issues" section later on in this
document.

=head2 Other required software for Compiling Perl on VMS

In addition to VMS and DCL you will need two things:

=over 4

=item 1  A C compiler. 

DEC (now Compaq) C or gcc for VMS (AXP or VAX).

=item 2  A make tool. 

DEC's MMS (v2.6 or later), or MadGoat's free MMS
analog MMK (available from ftp.madgoat.com/madgoat) both work
just fine. Gnu Make might work, but it's been so long since
anyone's tested it that we're not sure.  MMK is free though, so
go ahead and use that.

=back

=head2 Additional software that is optional for Perl on VMS

You may also want to have on hand:

=over 4

=item 1  GUNZIP/GZIP.EXE for VMS 

A de-compressor for *.gz and *.tgz files available from a number 
of web/ftp sites and is distributed on the OpenVMS Freeware CD-ROM 
from Compaq.

    http://www.fsf.org/order/ftp.html
    http://www.openvms.compaq.com/freeware/
    http://www.crinoid.com/utils/

=item 2  VMS TAR 

For reading and writing unix tape archives (*.tar files).  Vmstar is also 
available from a number of web/ftp sites and is distributed on the OpenVMS
Freeware CD-ROM from Compaq.

    ftp://ftp.lp.se/vms/
    http://www.openvms.compaq.com/freeware/

Recent versions of VMS tar on ODS-5 volumes may extract tape archive
files with ^. escaped periods in them.  See below for further workarounds.

=item 3  UNZIP.EXE for VMS

A combination decompressor and archive reader/writer for *.zip files.  
Unzip is available from a number of web/ftp sites.

    http://www.info-zip.org/UnZip.html
    http://www.openvms.compaq.com/freeware/
    ftp://ftp.openvms.compaq.com/
    ftp://ftp.madgoat.com/madgoat/
    ftp://ftp.process.com/vms-freeware/

=item 4  MOST

Most is an optional pager that is convenient to use with perldoc (unlike 
TYPE/PAGE, MOST can go forward and backwards in a document and supports 
regular expression searching).  Most builds with the slang 
library on VMS.  Most and slang are available from:

    ftp://space.mit.edu/pub/davis/
    ftp://ftp.process.com/vms-freeware/narnia/

=item 5 GNU PATCH and DIFFUTILS for VMS

Patches to Perl are usually distributed as GNU unified or contextual diffs. 
Such patches are created by the GNU diff program (part of the diffutils
distribution) and applied with GNU patch.  VMS ports of these utilities are
available here:

    http://www.crinoid.com/utils/
    http://www.openvms.compaq.com/freeware/

=back

Please note that UNZIP and GUNZIP are not the same thing (they work with
different formats).  Many of the useful files from CPAN (the Comprehensive
Perl Archive Network) are in *.tar.gz or *.tgz format (this includes copies 
of the source code for perl as well as modules and scripts that you may 
wish to add later) hence you probably want to have GUNZIP.EXE and 
VMSTAR.EXE on your VMS machine.

If you want to include socket support, you'll need a TCP/IP stack and either
DEC C, or socket libraries.  See the "Socket Support (optional)" topic 
for more details.

=head1 Unpacking the Perl source code

You may need to set up a foreign symbol for the unpacking utility of choice.

If you unpack a perl source kit with a name containing multiple periods on
an ODS-5 volume using recent versions of vmstar (e.g. V3.4 or later) you may
need to be especially careful in unpacking the tape archive file.  Try to use
the ODS-2 compatability qualifiers such as:

    vmstar /extract/verbose/ods2 perl-V^.VIII^.III.tar

or:

    vmstar -xvof perl-5^.8^.8.tar

If you neglected to use the /ODS2 qualifier or the -o switch then you
could rename the source directory:

    set security/protection=(o:rwed) perl-5^.8^.8.dir
    rename perl-5^.8^.8.dir perl-5_8_8.dir

Perl on VMS as of 5.8.8 does not completely handle extended file
parse styles such as are encountered on ODS-5.  While it can be built,
installed, and run on ODS-5 filesystems; it may encounter
trouble with characters that are otherwise illegal on ODS-2
volumes (notably the ^. escaped period sequence).

=head1 Configuring the Perl build

To configure perl (a necessary first step), issue the command

   @ Configure

from the top of an unpacked perl source directory.  You will be asked a 
series of questions, and the answers to them (along with the capabilities 
of your C compiler and network stack) will determine how perl is custom 
built for your machine.

If you have multiple C compilers installed, you'll have your choice of
which one to use.  Various older versions of DEC C had some caveats, so if
you're using a version older than 5.2, check the "DEC C Issues" section.

If you have any symbols or logical names in your environment that may 
interfere with the build or regression testing of perl then configure.com 
will try to warn you about them.  If a logical name is causing
you trouble but is in an LNM table that you do not have write access to
then try defining your own to a harmless equivalence string in a table 
such that it is resolved before the other (e.g. if TMP is defined in the
SYSTEM table then try DEFINE TMP "NL:" or somesuch in your process table) 
otherwise simply deassign the dangerous logical names.  The potentially 
troublesome logicals and symbols are:

    COMP    "LOGICAL"
    EXT     "LOGICAL"
    FOO     "LOGICAL"
    LIB     "LOGICAL"
    LIST    "LOGICAL"
    MIME    "LOGICAL"
    POSIX   "LOGICAL"
    SYS     "LOGICAL"
    T       "LOGICAL"
    THREAD  "LOGICAL"
    THREADS "LOGICAL"
    TIME    "LOGICAL"
    TMP     "LOGICAL"
    UNICODE "LOGICAL"
    UTIL    "LOGICAL"
    TEST    "SYMBOL"

As a handy shortcut, the command:

    @ Configure "-des"

(note the quotation marks and case) will choose reasonable defaults 
automatically (it takes DEC C over Gnu C, DEC C sockets over SOCKETSHR 
sockets, and either over no sockets).  Some options can be given
explicitly on the command line; the following example specifies a 
non-default location for where Perl will be installed:

    @ Configure "-d" "-Dprefix=dka100:[utils.perl5.]"

Note that the installation location would be by default where you unpacked 
the source with a "_ROOT." appended.  For example if you unpacked the perl 
source into:

   DKA200:[PERL-5_10_2...]

Then the PERL_SETUP.COM that gets written out by CONFIGURE.COM will
try to DEFINE your installation PERL_ROOT to be:

   DKA200:[PERL-5_10_2_ROOT.]

More help with configure.com is available from:

    @ Configure "-h"

See the "Changing compile-time options (optional)" section below to learn
even more details about how to influence the outcome of the important 
configuration step.  If you find yourself reconfiguring and rebuilding 
then be sure to also follow the advice in the "Cleaning up and starting 
fresh (optional)" and the checklist of items in the "CAVEATS" sections 
below.

=head2 Changing compile-time options (optional) for Perl on VMS

Most of the user definable features of Perl are enabled or disabled in
configure.com, which processes the hints file config_h.SH.  There is
code in there to Do The Right Thing, but that  may end up being the
wrong thing for you.  Make sure you understand what you are doing since
inappropriate changes to configure.com or config_h.SH can render perl 
unbuildable; odds are that there's nothing in there you'll need to
change.

The one exception is the various *DIR install locations. Changing those
requires changes in genconfig.pl as well.  Be really careful if you need to
change these, as they can cause some fairly subtle problems.

=head2 Socket Support (optional) for Perl on VMS

Perl includes a number of functions for IP sockets, which are available if
you choose to compile Perl with socket support.  Since IP networking is an 
optional addition to VMS, there are several different IP stacks available.  
How well integrated they are into the system depends on the stack, your 
version of VMS, and the version of your C compiler.

The most portable solution uses the SOCKETSHR library. In combination with
either UCX or NetLib, this supports all the major TCP stacks (Multinet,
Pathways, TCPWare, UCX, and CMU) on all versions of VMS Perl runs on, with
all the compilers on both VAX and Alpha. The socket interface is also
consistent across versions of VMS and C compilers. It has a problem with
UDP sockets when used with Multinet, though, so you should be aware of
that.

The other solution available is to use the socket routines built into DEC
C. Which routines are available depend on the version of VMS you're
running, and require proper UCX emulation by your TCP/IP vendor.
Relatively current versions of Multinet, TCPWare, Pathway, and UCX all
provide the required libraries--check your manuals or release notes to see
if your version is new enough.

=head1 Building Perl

The configuration script will print out, at the very end, the MMS or MMK
command you need to compile perl.  Issue it (exactly as printed) to start
the build.  

Once you issue your MMS or MMK command, sit back and wait.  Perl should 
compile and link without a problem.  If a problem does occur check the 
"CAVEATS" section of this document.  If that does not help send some 
mail to the VMSPERL mailing list.  Instructions are in the "Mailing Lists" 
section of this document.

=head1 Testing Perl

Once Perl has built cleanly you need to test it to make sure things work.
This step is very important since there are always things that can go wrong
somehow and yield a dysfunctional Perl for you.

Testing is very easy, though, as there's a full test suite in the perl
distribution.  To run the tests, enter the *exact* MMS line you used to
compile Perl and add the word "test" to the end, like this:

If the compile command was:

    MMS

then the test command ought to be: