searching cpan.org from the commandline

Question

I'm wondering if there's a feature to CPAN that allows the user to search all the modules available at CPAN.org.

I could probably just write something that sends the get request and spits back the answers...just wondering if there is already a built in utility...it would be really great.

I like how in debian or ubuntu linux, there is this thing "apt-cache search", or "aptitude search", that shows you which packages are already installed, and which packages are potentially available for you system. It would be a really great thing if there was something like this for perl modules/CPAN.

Answer 1

You can run Perl's CPAN module interactively:

# perl -MCPAN -e shell
Terminal does not support AddHistory.

cpan shell -- CPAN exploration and modules installation (v1.9800)
Enter 'h' for help.

cpan[1]> i /JSON::XS/
Reading '/home/alt/.cpan/Metadata'
  Database was generated on Wed, 06 Mar 2013 23:07:32 GMT
Module  < Catalyst::Action::Deserialize::JSON::XS (BOBTFISH/Catalyst-Action-REST-1.06.tar.gz)
Module  < Catalyst::Action::Serialize::JSON::XS (BOBTFISH/Catalyst-Action-REST-1.06.tar.gz)
Module  < JSON::XS               (MLEHMANN/JSON-XS-2.33.tar.gz)
Module  < JSON::XS::Boolean      (MLEHMANN/JSON-XS-2.33.tar.gz)
Module  < JSON::XS::VersionOneAndTwo (LBROCARD/JSON-XS-VersionOneAndTwo-0.31.tar.gz)
Module  < Mojo::JSON::XS         (YSYROTA/Mojo-JSON-Any-0.990104.tar.gz)
Module  < Mojo::JSON::XS::_Bool  (VTI/Mojo-JSON-Any-0.990103.tar.gz)
Module  < Sledge::Plugin::JSON::XS (TOKUHIROM/Sledge-Plugin-JSON-XS-0.05.tar.gz)
8 items found

Answer 2

There's also the cpan script that may be in your path. So, instead of typing

perl -MCPAN -eshell

you can just type

cpan

And that drops you into the CPAN shell.

Then, from the CPAN> prompt, you type i /ModuleName/ to search for modules. What would be really nice is to have the cpan script handle the i /ModuleName/ but for now, only -L is available which lists a particular module author's modules.

Answer 3

Yes, there is. What have you tried?

Here's the CPAN manual describing everything you can do from the command line.

Specifically, after you run cpan in interactive mode, m Module::Name will search for a module.

Answer 4

In my opinion, entering the cpan shell is not really "from the commandline".

I needed the ability to pipe the output of cpan to other external commands (grep/awk/sed/etc)

To that end this syntax works

echo 'm /keyword/' | cpan

examples:

-sh-4.2$ echo 'm /SFTP/' | cpan | grep   Recursive
Module  < Net::SFTP::Recursive   (GEOTIGER/Net-SFTP-Recursive-0.12.tar.gz)

or 
-sh-4.2$ echo 'm /SFTP.*Recursive/' | cpan

cpan shell -- CPAN exploration and modules installation (v1.9800)
Enter 'h' for help.

cpan[1]> Reading '/home/myuser/.cpan/Metadata'
  Database was generated on Thu, 14 Oct 2021 17:17:03 GMT
Module id = Net::SFTP::Recursive
    CPAN_USERID  GEOTIGER (Geo Tiger <tiger.geo@gmail.com>)
    CPAN_VERSION undef
    CPAN_FILE    G/GE/GEOTIGER/Net-SFTP-Recursive-0.12.tar.gz
    INST_FILE    (not installed)
cpan[2]> Lockfile removed.

Of course it would be quite easy to create a script to do this

cat << EOF > cpancmd
#!/bin/ksh
echo "\$*" | cpan
EOF
chmod 755 cpancmd
./cpancmd m /SFTP/ | grep Recursive

Or using more specific scripts or aliases to target sub commands "i" or "m" etc..