NAME

       cpan - easily interact with CPAN from the command line

SYNOPSIS

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

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

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

               # without arguments, starts CPAN.pm shell
               cpan

               # force install modules (usually those that fail tests)
               cpan -f module_name [ module_name ... ]

               # install modules but without testing them
               cpan -T module_name [ module_name ... ]

               # dump the configuration
               cpan -J

               # load a different configuration to install Module::Foo
               cpan -j some/other/file Module::Foo

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

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.

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

       -A module [ module ... ]
           Shows the primary maintainers for the specified modules.

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

       -C module [ module ... ]
           Show the Changes files for the specified modules

       -D module [ module ... ]
           Show the module details.

       -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

       -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 "-j", and that
           config sets up its own work directories.

       -g module [ module ... ]
           Downloads to the current directory the latest distribution of the module.

       -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 "Git::CPAN::Patch" distribution.

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

       -i  Install the specified modules.

       -I  Load "local::lib" (think like "-I" for loading lib paths).

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

       -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.

       -l  List all installed modules with their versions

       -L author [ author ... ]
           List the modules by the specified authors.

       -m  Make the specified modules.

       -O  Show the out-of-date modules.

       -p  Ping the configured mirrors

       -P  Find the best mirrors you could be using (but doesn't configure them just yet)

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

       -t  Run a `make test` on the specified modules.

       -T  Do not test modules. Simply install them.

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

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

       -V  Print detailed information about the cpan client.

       -w  UNIMPLEMENTED

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

   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

ENVIRONMENT VARIABLES

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

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

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

           CPAN_OPTS
               "cpan" splits this variable on whitespace and prepends that list to @ARGV before
               it processes the command-line arguments. For instance, if you always want to use
               "local:lib", you can set "CPAN_OPTS" to "-I".

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

           GIT_COMMAND
               The path to the "git" binary to use for the Git features. The default is
               "/usr/local/bin/git".

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

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

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

TO DO

       * one shot configuration values from the command line

BUGS

       * none noted

SEE ALSO

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

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.

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

AUTHOR

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

COPYRIGHT

       Copyright (c) 2001-2014, brian d foy, All Rights Reserved.

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