=head1 NAME

perlmodinstall - Installing CPAN Modules

=head1 DESCRIPTION

You can think of a module as the fundamental unit of reusable Perl
code; see L<perlmod> for details.  Whenever anyone creates a chunk of
Perl code that they think will be useful to the world, they register
as a Perl developer at L<https://www.cpan.org/modules/04pause.html>
so that they can then upload their code to the CPAN.  The CPAN is the
Comprehensive Perl Archive Network and can be accessed at
L<https://www.cpan.org/> , and searched at L<https://metacpan.org/> .

This documentation is for people who want to download CPAN modules
and install them on their own computer.

=head2 PREAMBLE

First, are you sure that the module isn't already on your system?  Try
C<perl -MFoo -e 1>.  (Replace "Foo" with the name of the module; for
instance, C<perl -MCGI::Carp -e 1>.)

If you don't see an error message, you have the module.  (If you do
see an error message, it's still possible you have the module, but
that it's not in your path, which you can display with C<perl -e
"print qq(@INC)">.)  For the remainder of this document, we'll assume
that you really honestly truly lack an installed module, but have
found it on the CPAN.

So now you have a file ending in .tar.gz (or, less often, .zip).  You
know there's a tasty module inside.  There are four steps you must now
take:

=over 5

=item B<DECOMPRESS> the file

=item B<UNPACK> the file into a directory

=item B<BUILD> the module (sometimes unnecessary)

=item B<INSTALL> the module.

=back

Here's how to perform each step for each operating system.  This is
<not> a substitute for reading the README and INSTALL files that
might have come with your module!

Also note that these instructions are tailored for installing the
module into your system's repository of Perl modules, but you can
install modules into any directory you wish.  For instance, where I
say C<perl Makefile.PL>, you can substitute C<perl Makefile.PL
PREFIX=/my/perl_directory> to install the modules into
F</my/perl_directory>.  Then you can use the modules from your Perl
programs with C<use lib "/my/perl_directory/lib/site_perl";> or
sometimes just C<use "/my/perl_directory";>.  If you're on a system
that requires superuser/root access to install modules into the
directories you see when you type C<perl -e "print qq(@INC)">, you'll
want to install them into a local directory (such as your home
directory) and use this approach.

=over 4

=item *

B<If you're on a Unix or Unix-like system,>

You can use Andreas Koenig's CPAN module
( L<https://metacpan.org/release/CPAN> )
to automate the following steps, from DECOMPRESS through INSTALL.

A. DECOMPRESS

Decompress the file with C<gzip -d yourmodule.tar.gz>

You can get gzip from L<ftp://prep.ai.mit.edu/pub/gnu/>

Or, you can combine this step with the next to save disk space:

     gzip -dc yourmodule.tar.gz | tar -xof -

B. UNPACK

Unpack the result with C<tar -xof yourmodule.tar>

C. BUILD

Go into the newly-created directory and type:

      perl Makefile.PL
      make test

or

      perl Makefile.PL PREFIX=/my/perl_directory

to install it locally.  (Remember that if you do this, you'll have to
put C<use lib "/my/perl_directory";> near the top of the program that
is to use this module.

D. INSTALL

While still in that directory, type:

      make install

Make sure you have the appropriate permissions to install the module
in your Perl 5 library directory.  Often, you'll need to be root.

That's all you need to do on Unix systems with dynamic linking.
Most Unix systems have dynamic linking. If yours doesn't, or if for
another reason you have a statically-linked perl, B<and> the
module requires compilation, you'll need to build a new Perl binary
that includes the module.  Again, you'll probably need to be root.

=item *

B<If you're running ActivePerl (Win95/98/2K/NT/XP, Linux, Solaris),>

First, type C<ppm> from a shell and see whether ActiveState's PPM
repository has your module.  If so, you can install it with C<ppm> and
you won't have to bother with any of the other steps here.  You might
be able to use the CPAN instructions from the "Unix or Linux" section
above as well; give it a try.  Otherwise, you'll have to follow the
steps below.

   A. DECOMPRESS

You can use the
open source 7-zip ( L<https://www.7-zip.org/> )
or the shareware Winzip ( L<https://www.winzip.com> ) to
decompress and unpack modules.

   B. UNPACK

If you used WinZip, this was already done for you.

   C. BUILD

You'll need either C<nmake> or C<gmake>.

Does the module require compilation (i.e. does it have files that end
in .xs, .c, .h, .y, .cc, .cxx, or .C)?  If it does, life is now
officially tough for you, because you have to compile the module
yourself (no easy feat on Windows).  You'll need a compiler such as
Visual C++.  Alternatively, you can download a pre-built PPM package
from ActiveState.
L<http://aspn.activestate.com/ASPN/Downloads/ActivePerl/PPM/>

Go into the newly-created directory and type:

      perl Makefile.PL
      nmake test


   D. INSTALL

While still in that directory, type:

      nmake install

=item *

B<If you're on OS/2,>

Get the EMX development suite and gzip/tar from Hobbes (
L<http://hobbes.nmsu.edu/h-browse.php?dir=/pub/os2/dev/emx/v0.9d> ), and then follow
the instructions for Unix.

=item *

B<If you're on VMS,>

When downloading from CPAN, save your file with a C<.tgz>
extension instead of C<.tar.gz>.  All other periods in the
filename should be replaced with underscores.  For example,
C<Your-Module-1.33.tar.gz> should be downloaded as
C<Your-Module-1_33.tgz>.

A. DECOMPRESS

Type

    gzip -d Your-Module.tgz

or, for zipped modules, type

    unzip Your-Module.zip

Executables for gzip, zip, and VMStar:

    http://www.hp.com/go/openvms/freeware/

and their source code:

    http://www.fsf.org/order/ftp.html

Note that GNU's gzip/gunzip is not the same as Info-ZIP's zip/unzip
package.  The former is a simple compression tool; the latter permits
creation of multi-file archives.

B. UNPACK

If you're using VMStar:

     VMStar xf Your-Module.tar

Or, if you're fond of VMS command syntax:

     tar/extract/verbose Your_Module.tar

C. BUILD

Make sure you have MMS (from Digital) or the freeware MMK ( available
from MadGoat at L<http://www.madgoat.com> ).  Then type this to create
the DESCRIP.MMS for the module:

    perl Makefile.PL

Now you're ready to build:

    mms test

Substitute C<mmk> for C<mms> above if you're using MMK.

D. INSTALL

Type

    mms install

Substitute C<mmk> for C<mms> above if you're using MMK.

=item *

B<If you're on MVS>,

Introduce the F<.tar.gz> file into an HFS as binary; don't translate from
ASCII to EBCDIC.

A. DECOMPRESS

Decompress the file with C<gzip -d yourmodule.tar.gz>

You can get gzip from
L<http://www.s390.ibm.com/products/oe/bpxqp1.html>

B. UNPACK

Unpack the result with

     pax -o to=IBM-1047,from=ISO8859-1 -r < yourmodule.tar

The BUILD and INSTALL steps are identical to those for Unix.  Some
modules generate Makefiles that work better with GNU make, which is
available from L<http://www.mks.com/s390/gnu/>

=back

=head1 PORTABILITY

Note that not all modules will work with on all platforms.
See L<perlport> for more information on portability issues.
Read the documentation to see if the module will work on your
system.  There are basically three categories
of modules that will not work "out of the box" with all
platforms (with some possibility of overlap):

=over 4

=item *

B<Those that should, but don't.>  These need to be fixed; consider
contacting the author and possibly writing a patch.

=item *

B<Those that need to be compiled, where the target platform
doesn't have compilers readily available.>  (These modules contain
F<.xs> or F<.c> files, usually.)  You might be able to find
existing binaries on the CPAN or elsewhere, or you might
want to try getting compilers and building it yourself, and then
release the binary for other poor souls to use.

=item *

B<Those that are targeted at a specific platform.>
(Such as the Win32:: modules.)  If the module is targeted
specifically at a platform other than yours, you're out
of luck, most likely.

=back



Check the CPAN Testers if a module should work with your platform
but it doesn't behave as you'd expect, or you aren't sure whether or
not a module will work under your platform.  If the module you want
isn't listed there, you can test it yourself and let CPAN Testers know,
you can join CPAN Testers, or you can request it be tested.

    https://cpantesters.org/


=head1 HEY

If you have any suggested changes for this page, let me know.  Please
don't send me mail asking for help on how to install your modules.
There are too many modules, and too few Orwants, for me to be able to
answer or even acknowledge all your questions.  Contact the module
author instead, ask someone familiar with Perl on your operating
system, or if all else fails, file a ticket at L<https://rt.cpan.org/>.

=head1 AUTHOR

Jon Orwant

orwant@medita.mit.edu

with invaluable help from Chris Nandor, and valuable help from Brandon
Allbery, Charles Bailey, Graham Barr, Dominic Dunlop, Jarkko
Hietaniemi, Ben Holzman, Tom Horsley, Nick Ing-Simmons, Tuomas
J. Lukka, Laszlo Molnar, Alan Olsen, Peter Prymmer, Gurusamy Sarathy,
Christoph Spalinger, Dan Sugalski, Larry Virden, and Ilya Zakharevich.

First version July 22, 1998; last revised November 21, 2001.

=head1 COPYRIGHT

Copyright (C) 1998, 2002, 2003 Jon Orwant.  All Rights Reserved.

This document may be distributed under the same terms as Perl itself.
