#!/usr/bin/perl

BEGIN { pop @INC if $INC[-1] eq '.' }
use strict;
use vars qw($VERSION);

use App::Cpan;
use CPAN::Version;
my $minver = '1.64';
if ( CPAN::Version->vlt($App::Cpan::VERSION, $minver) ) {
    warn "WARNING: your version of App::Cpan is $App::Cpan::VERSION while we would expect at least $minver";
}
$VERSION = '1.64';

my $rc = App::Cpan->run( @ARGV );

# will this work under Strawberry Perl?
exit( $rc || 0 );

=head1 NAME

cpan - easily interact with CPAN from the command line

=head1 SYNOPSIS

	# with arguments and no switches, installs specified modules
	cpan module_name [ module_name ... ]

	# with switches, installs modules with extra behavior
	cpan [-cfFimtTw] module_name [ module_name ... ]

	# use local::lib
	cpan -I module_name [ module_name ... ]

	# one time mirror override for faster mirrors
	cpan -p ...

	# with just the dot, install from the distribution in the
	# current directory
	cpan .

	# without arguments, starts CPAN.pm shell
	cpan

	# without arguments, but some switches
	cpan [-ahpruvACDLOPX]

=head1 DESCRIPTION

This script provides a command interface (not a shell) to CPAN. At the
moment it uses CPAN.pm to do the work, but it is not a one-shot command
runner for CPAN.pm.

=head2 Options

=over 4

=item -a

Creates a CPAN.pm autobundle with CPAN::Shell->autobundle.

=item -A module [ module ... ]

Shows the primary maintainers for the specified modules.

=item -c module

Runs a `make clean` in the specified module's directories.

=item -C module [ module ... ]

Show the F<Changes> files for the specified modules

=item -D module [ module ... ]

Show the module details. This prints one line for each out-of-date module
(meaning, modules locally installed but have newer versions on CPAN).
Each line has three columns: module name, local version, and CPAN
version.

=item -f

Force the specified action, when it normally would have failed. Use this
to install a module even if its tests fail. When you use this option,
-i is not optional for installing a module when you need to force it:

	% cpan -f -i Module::Foo

=item -F

Turn off CPAN.pm's attempts to lock anything. You should be careful with
this since you might end up with multiple scripts trying to muck in the
same directory. This isn't so much of a concern if you're loading a special
config with C<-j>, and that config sets up its own work directories.

=item -g module [ module ... ]

Downloads to the current directory the latest distribution of the module.

=item -G module [ module ... ]

UNIMPLEMENTED

Download to the current directory the latest distribution of the
modules, unpack each distribution, and create a git repository for each
distribution.

If you want this feature, check out Yanick Champoux's C<Git::CPAN::Patch>
distribution.

=item -h

Print a help message and exit. When you specify C<-h>, it ignores all
of the other options and arguments.

=item -i module [ module ... ]

Install the specified modules. With no other switches, this switch
is implied.

=item -I

Load C<local::lib> (think like C<-I> for loading lib paths). Too bad
C<-l> was already taken.

=item -j Config.pm

Load the file that has the CPAN configuration data. This should have the
same format as the standard F<CPAN/Config.pm> file, which defines
C<$CPAN::Config> as an anonymous hash.

=item -J

Dump the configuration in the same format that CPAN.pm uses. This is useful
for checking the configuration as well as using the dump as a starting point
for a new, custom configuration.

=item -l

List all installed modules with their versions

=item -L author [ author ... ]

List the modules by the specified authors.

=item -m

Make the specified modules.

=item -M mirror1,mirror2,...

A comma-separated list of mirrors to use for just this run. The C<-P>
option can find them for you automatically.

=item -n

Do a dry run, but don't actually install anything. (unimplemented)

=item -O

Show the out-of-date modules.

=item -p

Ping the configured mirrors and print a report

=item -P

Find the best mirrors you could be using and use them for the current
session.

=item -r

Recompiles dynamically loaded modules with CPAN::Shell->recompile.

=item -s

Drop in the CPAN.pm shell. This command does this automatically if you don't
specify any arguments.

=item -t module [ module ... ]

Run a `make test` on the specified modules.

=item -T

Do not test modules. Simply install them.

=item -u

Upgrade all installed modules. Blindly doing this can really break things,
so keep a backup.

=item -v

Print the script version and CPAN.pm version then exit.

=item -V

Print detailed information about the cpan client.

=item -w

UNIMPLEMENTED

Turn on cpan warnings. This checks various things, like directory permissions,
and tells you about problems you might have.

=item -x module [ module ... ]

Find close matches to the named modules that you think you might have
mistyped. This requires the optional installation of Text::Levenshtein or
Text::Levenshtein::Damerau.

=item -X

Dump all the namespaces to standard output.

=back

=head2 Examples

	# print a help message
	cpan -h

	# print the version numbers
	cpan -v

	# create an autobundle
	cpan -a

	# recompile modules
	cpan -r

	# upgrade all installed modules
	cpan -u

	# install modules ( sole -i is optional )
	cpan -i Netscape::Booksmarks Business::ISBN

	# force install modules ( must use -i )
	cpan -fi CGI::Minimal URI

	# install modules but without testing them
	cpan -Ti CGI::Minimal URI

=head2 Environment variables

There are several components in CPAN.pm that use environment variables.
The build tools, L<ExtUtils::MakeMaker> and L<Module::Build> use some,
while others matter to the levels above them. Some of these are specified
by the Perl Toolchain Gang:

Lancaster Concensus: L<https://github.com/Perl-Toolchain-Gang/toolchain-site/blob/master/lancaster-consensus.md>

Oslo Concensus: L<https://github.com/Perl-Toolchain-Gang/toolchain-site/blob/master/oslo-consensus.md>

=over 4

=item NONINTERACTIVE_TESTING

Assume no one is paying attention and skips prompts for distributions
that do that correctly. C<cpan(1)> sets this to C<1> unless it already
has a value (even if that value is false).

=item PERL_MM_USE_DEFAULT

Use the default answer for a prompted questions. C<cpan(1)> sets this
to C<1> unless it already has a value (even if that value is false).

=item CPAN_OPTS

As with C<PERL5OPT>, a string of additional C<cpan(1)> options to
add to those you specify on the command line.

=item CPANSCRIPT_LOGLEVEL

The log level to use, with either the embedded, minimal logger or
L<Log::Log4perl> if it is installed. Possible values are the same as
the C<Log::Log4perl> levels: C<TRACE>, C<DEBUG>, C<INFO>, C<WARN>,
C<ERROR>, and C<FATAL>. The default is C<INFO>.

=item GIT_COMMAND

The path to the C<git> binary to use for the Git features. The default
is C</usr/local/bin/git>.

=back

=head1 EXIT VALUES

The script exits with zero if it thinks that everything worked, or a
positive number if it thinks that something failed. Note, however, that
in some cases it has to divine a failure by the output of things it does
not control. For now, the exit codes are vague:

	1	An unknown error

	2	The was an external problem

	4	There was an internal problem with the script

	8	A module failed to install

=head1 NOTES  

If the configuration is not defined when C<cpan> is used for the first
time, CPAN::Config initialization is triggered using L<CPAN::FirstTime>.
This step is skipped only when using the C<-h> option.

If the user has write permissions to /usr/local, site library repositories
may also be created.

=head1 TO DO

* one shot configuration values from the command line

=head1 BUGS

* none noted

=head1 SEE ALSO

Most behaviour, including environment variables and configuration,
comes directly from CPAN.pm.

=head1 SOURCE AVAILABILITY

This code is in Github in the CPAN.pm repository:

	https://github.com/andk/cpanpm

The source used to be tracked separately in another GitHub repo,
but the canonical source is now in the above repo.

=head1 CREDITS

Japheth Cleaver added the bits to allow a forced install (-f).

Jim Brandt suggest and provided the initial implementation for the
up-to-date and Changes features.

Adam Kennedy pointed out that exit() causes problems on Windows
where this script ends up with a .bat extension

=head1 AUTHOR

brian d foy, C<< <bdfoy@cpan.org> >>

=head1 COPYRIGHT

Copyright (c) 2001-2015, brian d foy, All Rights Reserved.

You may redistribute this under the same terms as Perl itself.

=cut

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