Linux Commands Examples

A great documentation place for Linux commands


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 [-cfgimt] module_name [ module_name ... ]
        # with just the dot, install from the distribution in the
        # current directory
        cpan .
        # without arguments, starts shell
        # 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]

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cpan_file=$(which cpan);
for i in `cat $cpan_list`
for i in `cat $cpan_list`
cat <<EOF
>> cpan $i
\$ cpan $cpan_term_args $i;

CPAN install to many directories

Either local::lib or Perlbrew (or both) should be able to simplify things for you. Even more importantly, don't use CPAN to install modules; use cpanm.

My preference is simply to use Perlbrew to install non-system Perl interpreters in my $HOME directory. After that, each interpreter is self-contained and cpanm takes care of modules. Honestly, I never need to think about where modules end up. It just works.


Installing a CPAN module using a remote compiler

Compile elsewhere, and install the result. CentOS of the same version as RHEL should work fine for this.


how to get Geo::Coder::Many with cpan? Going to build K/KA/KAORU/Geo-Coder-Many-0.42.tar.gz

Can't locate Geo/Coder/Many/ in @INC (@INC contains: /etc/perl /usr/local/lib/perl/5.14.2 /usr/local/share/perl/5.14.2 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.14 /usr/share/perl/5.14 /usr/local/lib/site_perl .) at /usr/share/perl/5.14/Module/ line 27. Can't locate ...

Geo::Coder::Many::Google is a plugin that comes bundled with Geo::Coder::Many to translate between Geo::Coder::Google and Geo::Coder::Many. As you can see from this URL:

(Note that Geo/Coder/Many/ belongs to the Geo-Coder-Many 0.42 package.)

This implies that during the 'make test' your environment was not correctly configured to include the packages' own modules in the @INC or $PERL5LIB during the test. Which is weird because that should definitely be the default.

To go a bit more general:

Geo::Coder::Many attempts to dynamically generated its dependency list based on what Geo::Coder::* modules you have installed. It's worth noting that Geo::Coder::Google and Geo::Coder::Googlev3 are different modules - specifically Geo::Coder::Google is used for version 2 of Google's Geocoder API.

This means that the first part of your question is not entirely relevant. It's not failing on Google v3 support, it's failing on Google v2 support, which you must also have installed.

I suggest trying to:

sudo cpan App::cpanminus
sudo cpanm --sudo --prompt Geo::Coder::Many

Then, assuming it fails again, use the prompt option to "Inspect" the build directory and try running 'make test' or './Build test' yourself... or alternatively use 'prove --blib' to test specific .t files that are relevant to your needs. If things work to your satisfaction you can drop out of the Inspect with 'exit' and then force the install through.


Install XML::Parser

Found a solution with this apt-get command :

sudo apt-get install expat 
sudo apt-get install libexpat1-dev

Thanks @daxlerod for your comment.


Install perl module with dependencies

This is unfortunately the tell-tale sign of a memory leakage. This command

ps --sort -rss -eo rss,pid,command | head

will tell you who the culprit is. Solving a problem like this is way above my pay grade, since it can basically be done only the program/system developers. You may try to contact them to report the problem.


Don't you have the curl command wrong? Should it not be

sudo curl -L | perl - --sudo App::cpanminus



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.



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. 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 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 ... ]


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.


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 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 author [ author ... ]

List the modules by the specified authors.


Make the specified modules.


Show the out-of-date modules.


Run a ’make test’ on the specified modules.


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


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


        # print a help message
        cpan -h
        # print the version numbers
        cpan -v
        # create an autobundle
        cpan -a
        # recompile modules
        cpan -r
        # install modules ( sole -i is optional )
        cpan -i Netscape::Booksmarks Business::ISBN
        # force install modules ( must use -i )
        cpan -fi CGI::Minimal URI


Copyright (c) 2001-2009, brian d foy, All Rights Reserved.

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


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

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

source availability

This code is in Github:


to do

* one shot configuration values from the command line


* none noted

see also

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


brian d foy, "<bdfoy[:at:]cpan[:dot:]org>"

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