So you’ve got this great new local CPAN you can use to install stuff you know about but how do you find stuff you don’t know about? There are two main ways I inspect the contents of my local CPAN mirror. The first is a simple shell function for searching package names, the second, has a bit more to it but we will save that for later.

grep to the Rescue

One of the metadata files in our local mirror is /modules/02packages.details.txt.gz. Let’s take a look inside.

File:         02packages.details.txt
URL:          http://www.perl.com/CPAN/modules/02packages.details.txt
Description:  Package names found in directory $CPAN/authors/id/
Columns:      package name, version, path
Intended-For: Automated fetch routines, namespace documentation.
Written-By:   CPAN::Mini::Inject 0.33
Line-Count:   145223
Last-Updated: Tue, 12 Aug 2014 15:01:40 GMT

AAA::Demo                         undef  J/JW/JWACH/Apache-FastForward-1.1.tar.gz
AAA::eBay                         undef  J/JW/JWACH/Apache-FastForward-1.1.tar.gz
AAAA::Crypt::DH                    0.04  B/BI/BINGOS/AAAA-Crypt-DH-0.04.tar.gz
AAAA::Mail::SpamAssassin          0.002  S/SC/SCHWIGON/AAAA-Mail-SpamAssassin-0.002.tar.gz
AAAAAAAAA                          1.01  M/MS/MSCHWERN/AAAAAAAAA-1.01.tar.gz
AAC::Pvoice                        0.91  J/JO/JOUKE/AAC-Pvoice-0.91.tar.gz
AAC::Pvoice::Bitmap                1.12  J/JO/JOUKE/AAC-Pvoice-0.91.tar.gz
AAC::Pvoice::Dialog                1.01  J/JO/JOUKE/AAC-Pvoice-0.91.tar.gz
...

The format is pretty straightforward. After a few header lines, we have one line per package seen by the indexer. The lines consist of three whitespace separated columns of a package name, current package version (if the indexer found one), and latest distribution containing it. The AAC-Provoice and Apache-FastForward distributions show us that each individual package within the distribution is listed. We could easily use zgrep to find packages that match a pattern.

$ zgrep -i tiny ~/Dropbox/minicpan/modules/02packages.details.txt.gz
Acme::Has::Tiny                   0.001  T/TO/TOBYINK/Acme-Has-Tiny-0.001.tar.gz
Acme::Module::Build::Tiny          0.0   D/DA/DAGOLDEN/Acme-Acme-Module-Build-Tiny-0.06.tar.gz
Acme::Tiny                        0.003  E/ET/ETHER/Acme-Tiny-0.003.tar.gz
...

This is a little long to type regularly. A shell alias isn’t appropriate as we want to sandwich the provided input between zgrep and the path to the file. Fortunately, a shell function will allow us to do this without much more verbosity.

function cpangrep {
    zgrep $* /home/yourusername/Dropbox/minicpan/modules/02packages.details.txt.gz
}

Dropping this line in your .zshrc or .bashrc will allow you to search 02packages.details.txt.gz with the cpangrep command.

$ cpangrep tiny | wc -l
21
$ cpangrep -i tiny | wc -l
344
$ cpangrep -i tiny
Acme::Has::Tiny                   0.001  T/TO/TOBYINK/Acme-Has-Tiny-0.001.tar.gz
Acme::Module::Build::Tiny          0.06  D/DA/DAGOLDEN/Acme-Acme-Module-Build
...

Since we use $* instead of $1, all arguments we give to the function are passed on to zgrep. This allows us to do things like search with or without ignoring case on demand.

CPAN::Mini::Webserver

CPAN::Mini::Webserver provides a script that launches a web server providing an interface to your local minicpan. Usage couldn’t be easier, install CPAN::Mini::Webserver then run minicpan_webserver. By default the server binds to port 2963 but you can change this with the --port argument.

If you’ve used search.cpan.org or metacpan, there should be no surprises in how to navigate around the site. The documentation has information on a few things you can plug in to your .minicpanrc to enable things like full text indexing.

Here are a few screenshots of CPAN::Mini::Webserver to wet your appetite.

{% img /assets/2014/minicpan/index.png Index View %} {% img /assets/2014/minicpan/search_results.png Search Results %} {% img /assets/2014/minicpan/author_view.png Author View %} {% img /assets/2014/minicpan/dist_view.png Distribution View %} {% img /assets/2014/minicpan/module_view.png Module View %}