App::Cpan(3p) Perl Programmers Reference Guide App::Cpan(3p)NAMEApp::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 [-cfFimt] module_name [ module_name ... ]
# use local::lib
cpan -l module_name [ module_name ... ]
# with just the dot, install from the distribution in the
# current directory
# without arguments, starts CPAN.pm shell
# without arguments, but some switches
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.
-a Creates a CPAN.pm autobundle with CPAN::Shell->autobundle.
-A module [ module ... ]
Shows the primary maintainers for the specified modules.
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 This prints one line for each out-of-date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.
-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
% 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
-G module [ module ... ]
Download to the current directory the latest distribution of the
modules, unpack each distribution, and create a git repository for
If you want this feature, check out Yanick Champoux's
-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.
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 Use "local::lib".
-L author [ author ... ]
List the modules by the specified authors.
-m Make the specified modules.
-O Show the out-of-date modules.
-t Run a `make test` on the specified modules.
-r Recompiles dynamically loaded modules with CPAN::Shell->recompile.
-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.
# print a help message
# print the version numbers
# create an autobundle
# recompile modules
# upgrade all installed modules
# 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.
CPAN.pm sends all the good stuff either to STDOUT. I have to
intercept that output so I can find out what happened.
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 CPAN.pm output, I need to check for errors and report
them to the user.
* none noted
Most behaviour, including environment variables and configuration,
comes directly from CPAN.pm.
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
brian d foy, "<email@example.com>"
Copyright (c) 2001-2009, brian d foy, All Rights Reserved.
You may redistribute this under the same terms as Perl itself.
perl v5.12.2 September 28, 2010