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App::Cpan - easily interact with CPAN from the command line


# 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 ... ]

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

# without arguments, starts shell

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


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



Creates a 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. This prints one line for each out-of-date module (meaning, modules locally installed but have newer versions on CPAN).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.


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

Turn off'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 ... ]


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.


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


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


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


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


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


List all installed modules wth their versions

-L author [ author ... ]

List the modules by the specified authors.


Make the specified modules.


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


Show the out-of-date modules.


Ping the configured mirrors


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


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


Run a `make test` on the specified modules.


Do not test modules. Simply install them.


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


Print the script version and version then exit.


Print detailed information about the cpan client.



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


# 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



Just do it.

The run method returns 0 on success and a postive number on failure. See the section on EXIT CODES for details on the values. sends all the good stuff either to STDOUT, or to a temp file if $CPAN::Be_Silent is set. I have to intercept that output so I can find out what happened.

Stolen from File::Path::Expand


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


* There is initial support for Log4perl if it is available, but I haven't gone through everything to make the NullLogger work out correctly if Log4perl is not installed.

* When I capture output, I need to check for errors and report them to the user.

* Support local::lib

* Warnings switch

* Check then exit

* ping mirrors support

* no test option


* none noted


Most behaviour, including environment variables and configuration, comes directly from


This code is in Github:



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

David Golden helps integrate this into the repos.


brian d foy, <>


Copyright (c) 2001-2013, brian d foy, All Rights Reserved.

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