=head1 NAME

Catmandu::Introduction - An Introduction to Catmandu data processing toolkit

=begin markdown

# STATUS

[![Build Status](https://travis-ci.org/LibreCat/Catmandu.svg?branch=master)](https://travis-ci.org/LibreCat/Catmandu)
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[![CPANTS kwalitee](http://cpants.cpanauthors.org/dist/Catmandu.png)](http://cpants.cpanauthors.org/dist/Catmandu)

=end markdown

=head1 Introduction

Catmandu is a data processing toolkit developed as part of the L<LibreCat|http://librecat.org> project.
Catmandu provides the command line client L<catmandu> and a suite of tools to ease the import, storage,
retrieval, export and transformation of data. For instance, to transform a CSV file into JSON use the
command:

    $ catmandu convert JSON to CSV < data.json

Or, to store a YAML file into an ElasticSearch database type (requires L<Catmandu::ElasticSearch>):

    $ catmandu import YAML to ElasticSearch --index_name demo < test.yml

To export all the data from an Solr search engine into JSON type (requires L<Catmandu::Solr>):

    $ catmandu export Solr --url http://localhost:8983/solr to JSON

With Catmandu one can import OAI-PMH records in your application (requires L<Catmandu::OAI>):

    $ catmandu convert OAI --url http://biblio.ugent.be/oai --set allFtxt

and export records into formats such as JSON, YAML, CSV, XLS, RDF and many more.

Catmandu also provides a small scripting language to manipulate data, extract parts of your dataset and
transform records. For instance, rename fields  with the 'L<move_field|Catmandu::Fix::move_field>' Fix command:

    $ catmandu convert JSON --fix 'move_field(title,my_title)' < data.json

In the example above, we renamed all the 'title' fields in the dataset into the 'my_title' field.

One can also work on deeply nested data. E.g. create a deeply nested data structure with the
'move_field' Fix command:

    $ catmandu convert JSON --fix 'move_field(title,my.deeply.nested.title)' < data.json

In this example we moved the field 'title' into the field 'my', which contains a (sub)field 'deeply',
which contains a (sub)field 'nested'.

Catmandu was originally created by librarians for librarians. We process a lot of metadata especially
library metadata in formats such as MARC, MAB2 and MODS. With the following command we can extract
data from a marc record and to store it into the title field (requires L<Catmandu::MARC>):

    $ catmandu convert MARC --fix 'marc_map(245,title)' < data.mrc

Or, in case only the 245a subfield is needed write:

    $ catmandu convert MARC --fix 'marc_map(245a,title)' < data.mrc

When processing data a lot of Fix commands could be required. It wouldn't be very practical to
type them all on the command line. By creating a Fix script which contains all the fix commands complicated
data transformations can be created. For instance, if the file C<myfixes.txt> contains:

     marc_map(245a,title)
     marc_map(100a,author.$append)
     marc_map(700a,author.$append)
     marc_map(020a,isbn)
     replace_all(isbn,'[^0-9-]+','')

then they can be executed on a MARC file using this command:

    $ catmandu convert MARC --fix myfixes.txt < data.mrc

Fixes can also be turned into executable scripts by adding a bash 'shebang' line at the top. E.g.
to harvest records from an OAI repository write this fix file:

     #!/usr/bin/env catmandu run
     do importer(OAI,url:"http://lib.ugent.be/oai")
        add_to_exporter(.,JSON)
     end

Run this (on Linux) by setting the executable bit:

     $ chmod 755 myfix.fix
     $ ./myfix.fix

To experiment with the Fix language you can also run the catmandu Fix interpreter in an
interactive mode:

     $ catmandu run
     Catmandu 0.95 interactive mode
     Type: \h for the command history
     fix > add_field(hello,world)
     ---
     hello: world
     ...
     fix >

Catmandu contains many powerful fixes. Visit L<http://librecat.org/Catmandu/#fixes-cheat-sheet> to get
an overview what is possible.

=head1 Documentation

For more information read our L<documentation pages|http://librecat.org/Catmandu/>
and L<blog|https://librecatproject.wordpress.com/>
for a complete introduction and update into all Catmandu features.

In the winter of 2014 an Advent calendar tutorial was created to provide a day by
day introduction into the UNIX command line and Catmandu:

L<https://librecatproject.wordpress.com/2014/12/01/day-1-getting-catmandu/>

If you need extra training, our developers regulary host workshops at library
conferences and events: L<http://librecat.org/events.html>

=head1 Installation

There are several ways to get a working version of Catmandu on your computer.
For a quick and demo installation visit our L<blog|https://librecatproject.wordpress.com/get-catmandu/>
where a VirtualBox image is available containing all the Catmandu modules, including
ElasticSearch and MongoDB.

On our L<website|http://librecat.org/Catmandu/#installation> we provide installation instructions for:

=over

=item Debian

=item Ubuntu Server

=item CentOS

=item openSUSE

=item OpenBSD

=item Windows

=back

and even a generic installation using L<Docker|https://www.docker.com/>: L<https://hub.docker.com/r/librecat/catmandu/>.

=head1 Open Source

Catmandu software published at https://github.com/LibreCat/Catmandu is free software without warranty, liabilities
or support; you can redistribute it and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 or any later version. Every contributor is free
to state her/his copyright.

=head1 Developers & Support

Catmandu has a very active international developer community. We welcome all feedback, bug reports and
feature enhancement.

Join our mailing list to receive more information:  C<< librecat-dev@librecat.org >>

Are a developer and want to contribute to the project? Feel free to submit pull requests or create new
Catmandu packages!

=head1 Kudos

Catmandu is created in a cooperation with many developers world wide. Without them this project isn't possible.
We would like to thank our core maintainer: Nicolas Steenlant and all contributors: Christian Pietsch ,
Dave Sherohman , Friedrich Summann , Jakob Voss , Johann Rolschewski  , Jorgen Eriksson  , Magnus Enger ,
Maria Hedberg , Mathias Loesch , Najko Jahn , Nicolas Franck , Patrick Hochstenbach , Petra Kohorst  ,
Snorri Briem , Upasana Shukla and Vitali Peil

=head1 SEE ALSO

L<Catmandu>

L<http://librecat.org/>

=cut
