CPANPLUS::inc(3pm) Perl Programmers Reference Guide CPANPLUS::inc(3pm)
NAME
CPANPLUS::inc
DESCRIPTION
OBSOLETE
NAME
CPANPLUS::inc - runtime inclusion of privately bundled modules
SYNOPSIS
### set up CPANPLUS::inc to do it's thing ###
BEGIN { use CPANPLUS::inc };
### enable debugging ###
use CPANPLUS::inc qw[DEBUG];
DESCRIPTION
This module enables the use of the bundled modules in the "CPANPLUS/inc" directory of this package. These modules are bundled to make sure
"CPANPLUS" is able to bootstrap itself. It will do the following things:
Put a coderef at the beginning of @INC
This allows us to decide which module to load, and where to find it. For details on what we do, see the "INTERESTING MODULES" section
below. Also see the "CAVEATS" section.
Add the full path to the "CPANPLUS/inc" directory to "$ENV{PERL5LIB".
This allows us to find our bundled modules even if we spawn off a new process. Although it's not able to do the selective loading as
the coderef in @INC could, it's a good fallback.
METHODS
CPANPLUS::inc->inc_path()
Returns the full path to the "CPANPLUS/inc" directory.
CPANPLUS::inc->my_path()
Returns the full path to be added to @INC to load "CPANPLUS::inc" from.
CPANPLUS::inc->installer_path()
Returns the full path to the "CPANPLUS/inc/installers" directory.
CPANPLUS::inc->original_perl5lib
Returns the value of $ENV{PERL5LIB} the way it was when "CPANPLUS::inc" got loaded.
CPANPLUS::inc->original_perl5opt
Returns the value of $ENV{PERL5OPT} the way it was when "CPANPLUS::inc" got loaded.
CPANPLUS::inc->original_inc
Returns the value of @INC the way it was when "CPANPLUS::inc" got loaded.
CPANPLUS::inc->limited_perl5opt(@modules);
Returns a string you can assign to $ENV{PERL5OPT} to have a limited include facility from "CPANPLUS::inc". It will roughly look like:
-I/path/to/cpanplus/inc -MCPANPLUS::inc=module1,module2
CPANPLUS::inc->interesting_modules()
Returns a hashref with modules we're interested in, and the minimum version we need to find.
It would looks something like this:
{ File::Fetch => 0.06,
IPC::Cmd => 0.22,
....
}
INTERESTING MODULES
"CPANPLUS::inc" doesn't even bother to try find and find a module it's not interested in. A list of interesting modules can be obtained
using the "interesting_modules" method described above.
Note that all subclassed modules of an "interesting module" will also be attempted to be loaded, but a version will not be checked.
When it however does encounter a module it is interested in, it will do the following things:
Loop over your @INC
And for every directory it finds there (skipping all non directories -- see the "CAVEATS" section), see if the module requested can be
found there.
Check the version on every suitable module found in @INC
After a list of modules has been gathered, the version of each of them is checked to find the one with the highest version, and return
that as the module to "use".
This enables us to use a recent enough version from our own bundled modules, but also to use a newer module found in your path instead,
if it is present. Thus having access to bugfixed versions as they are released.
If for some reason no satisfactory version could be found, a warning will be emitted. See the "DEBUG" section for more details on how
to find out exactly what "CPANPLUS::inc" is doing.
DEBUG
Since this module does "Clever Things" to your search path, it might be nice sometimes to figure out what it's doing, if things don't work
as expected. You can enable a debug trace by calling the module like this:
use CPANPLUS::inc 'DEBUG';
This will show you what "CPANPLUS::inc" is doing, which might look something like this:
CPANPLUS::inc: Found match for 'Params::Check' in
'/opt/lib/perl5/site_perl/5.8.3' with version '0.07'
CPANPLUS::inc: Found match for 'Params::Check' in
'/my/private/lib/CPANPLUS/inc' with version '0.21'
CPANPLUS::inc: Best match for 'Params::Check' is found in
'/my/private/lib/CPANPLUS/inc' with version '0.21'
CAVEATS
This module has 2 major caveats, that could lead to unexpected behaviour. But currently I don't know how to fix them, Suggestions are much
welcomed.
On multiple "use lib" calls, our coderef may not be the first in @INC
If this happens, although unlikely in most situations and not happening when calling the shell directly, this could mean that a lower
(too low) versioned module is loaded, which might cause failures in the application.
Non-directories in @INC
Non-directories are right now skipped by CPANPLUS::inc. They could of course lead us to newer versions of a module, but it's too tricky
to verify if they would. Therefor they are skipped. In the worst case scenario we'll find the sufficing version bundled with CPANPLUS.
perl v5.10.0 2007-12-18 CPANPLUS::inc(3pm)