Q: How do I install my own perl5 modules

A:
To install your own Perl5 modules, first create some area to install
into, like /myperl/lib.  If this is in AFS and you want to install for
multiple arches, you'll have to do the normal @sys madness.

You can then set the PERLLIB and/or PERL5LIB environment vars to look
in that area; for example
    setenv PERLLIB /myperl/lib
You probably want to add this to your ~/.login file.

Now, you can build the modules.  I like using the interactive cpan
tool since (1) it compares installed modules to those at CPAN, (2)
warns you about a module's dependencies on other modules, (3) does the
downloading and unpacking for you, (4) generally makes things easier
(once you get it set up).  To run this interactive CPAN shell, do
    perl5 -MCPAN -e shell
See the CPAN(3) man page for the details and options.  The first time
you run it, it will ask you a series of questions and look for tools
it needs (gzip, tar, ...).  It will ask you for your nearest CPAN
site; there is one that is geographically close (somewhere in PA), but
the network between there and CMU wasn't the greatest when I first set
things up, so I use
    ftp://uiarchive.uiuc.edu/pub/lang/perl/CPAN/
It will save this data in ~/.cpan/CPAN/MyConfig.pm

Before you can build and install the modules, you'll need to edit the
~/.cpan/CPAN/MyConfig.pm file to tell CPAN to install the modules into
your area (otherwise, it tries to install into the main perl5 area
which you probably don't have write access to).  You'll need to edit
the flags that get passed to ``make install'' (this is the
make_install_arg variable).  Set it to something like:

 'make_install_arg' => join(" ",
   "  INSTALLSCRIPT=/myperl/bin",
   "     INSTALLBIN=/myperl/bin",
   " INSTALLPRIVLIB=/myperl/lib",
   " INSTALLARCHLIB=/myperl/lib",
   " INSTALLSITELIB=/myperl/lib",
   "INSTALLSITEARCH=/myperl/lib",
   " INSTALLMAN1DIR=/myperl/man/man1",
   " INSTALLMAN3DIR=/myperl/man/man3",
   ),

Change the ``/myperl'' part to the directory where you want to install
the modules and make sure the PERLLIB environment variable includes
that directory.

(If you plan to do this for multiple platforms, you'll need to do the
normal @sys stuff for the values of the INSTALLBIN, INSTALLARCHLIB,
and INSTALLSITEARCH variables).

You're welcome to look at /afs/cs/user/mthomas/.cpan/CPAN/MyConfig.pm,
but I will warn you it is pretty hairy since I want to use the same
MyConfig.pm file on different machines to install into different areas
(the CPAN collection versus the Perl/Tk collection versus my personal
collection) and I want the sources in AFS but my build area on the
local disk.

Once CPAN is set up, you can use the commands
        m /patt/           to search for modules by the regexp `patt'
        module <m>         to ask about the module <m>
        readme <m>         to download and display module <m>'s README
                           file--this is not always helpful since the
                           module's author writes this
        make <m>           to download and build module <m>
        test <m>           to run <m>'s tests (implies make)
        install <m>        to install the module (implies test)
        force install <m>  to force an install despite errors
See the man page for the details.