#!/usr/bin/env perl

use App::perlrdf;
App::perlrdf->run;

__END__

=head1 NAME

perlrdf - perlrdf command line utils

=head1 SYNOPSIS

   $ perlrdf make_store --sqlite=mystore.dat
   Initialized RDF::Trine::Store::DBI::SQLite

   $ perlrdf validate input.rdf
   1..1
   ok 1 - file:///tmp/example/input.rdf is valid RDFXML, 9 triples

   $ perlrdf store_load --autograph --sqlite=mystore.dat input.rdf
   Loading file:///tmp/example/input.rdf

   $ perlrdf store_dump --sqlite=mystore.dat output.nq
   Writing file:///tmp/example/output.nq

   $ perlrdf translate output.nq output.rdf

   $ perlrdf isomorphic input.rdf output.rdf
   graphs are isomorphic

=head1 DESCRIPTION

perlrdf is a single front-end to various RDF functionality available for
Perl. The core distribution includes commands for create and manipulate
quad stores (i.e. databases for RDF data); and commands to parse, serialise,
convert and validate RDF data in various formats.

However, perlrdf is pluggable and it is anticipated that plugins on CPAN
will cover other tasks such as RDF querying, signing, encryption, and
reasoning.

=head1 COMMANDS

This section describes the commands included with the core App::perlrdf
distribution. Others are available as plugins. Run C<< perlrdf commands >>
to see a list of locally installed commands.

=head2 Meta Commands

=head3 C<< perlrdf about >>

Shows the version numbers of all installed perlrdf commands, plus the CPAN
ID of each command's author.

=head3 C<< perlrdf aliases >>

Many commands have aliases or shortcuts. For example, the following two are
equivalent:

   $ perlrdf translate input.ttl output.rdf
   $ perlrdf tr input.ttl output.rdf

C<< perlrdf aliases >> shows a list of available aliases.

=head3 C<< perlrdf commands >>

Shows a list of installed perlrdf commands, along with a brief extract.

=head3 C<< perlrdf filespec >>

Shows help on "File Specifications". FileSpecs are an App::perlrdf-specific
microsyntax for specifying a filename or URI along with a tiny bit of
associated key-value metadata. The following are three examples of FileSpecs:

   {format:RDFXML}C:\Data\contacts.xml
   http://www.example.com/mydata.ttl
   {format:Turtle,base:"http://example.net/"}stdin:

Running the C<< perlrdf filespec >> command on its own shows some help on
using FileSpecs. If you run it with additional arguments, these are parsed
as FileSpecs with debugging information shown.

   $ perlrdf filespec /tmp/foo.rdf
   {
      "base" : "file:///tmp/foo.rdf",
      "format" : "RDF::Trine::Parser::RDFXML",
      "uri" : "file:///tmp/foo.rdf"
   }

=head3 C<< perlrdf help >>

Running the C<< perlrdf help >> command on its own shows a list of commands
with their abstracts. Detailed help for a particular command can be shown
by providing that as an argument. For example, for help on the
C<< perlrdf translate >> command, run:

   $ perlrdf help translate

=head2 Parsing and Serialization

In general, parsing and serialization commands take one or more FileSpecs
as arguments. These can be provided as options, as in:

   $ perlrdf translate --input-spec="in.nt" --output-spec="out.rdf"

Alternatively the first "positional argument" will usually be treated as
an input FileSpec, and the second as an output FileSpec:

   $ perlrdf translate in.nt out.rdf

Using options rather than positional parameters can often be clearer, and is
the recommended way of passing parameters, especially when you need to pass
multiple input files or multiple output files as parameters.

When no inputs are provided as named or positional arguments, STDIN is
normally used. When no outputs are provided, output normally goes to STDOUT.

=head3 C<< perlrdf canonicalize >>

Given a single FileSpec as input, serializes as canonical N-Triples, which
is a useful format for SHA1/MD5 digests, graph signing, etc, because it means
that incidental features of serialization (blank node identifiers, whitespace,
order of statements) don't affect the output. If no input FileSpec is
provided, then defaults to STDIN.

A filename or URL (but not a full FileSpec) may be provided for output.
Otherwise defaults to STDOUT.

=head3 C<< perlrdf translate >>

Parses one or more input FileSpecs into a single RDF graph and serializes
them to one or more output FileSpecs. Thus this command can be used as a
translator between different RDF serializations, and also as a graph
concatenator.

   $ perlrdf translate \
      --skolem \
      -i "{format:RDFXML}/tmp/contacts.xml" \
      -i "http://www.example.com/employees.ttl" \
      -o "merged-contacts.nt" \
      -o "merged-contacts.rdf"

The 'skolem' option allows you to generate URIs for any blank nodes in the
graph. (Not especially fantastic URIs, but URIs all the same.)

=head3 C<< perlrdf validate >>

Parses one or more input FileSpecs (doing nothing with the results), and
makes sure that each file parses without croaking. Writes output to STDOUT
in TAP format.

   $ perlrdf validate "foo.ttl" "ftp://acme.example.com/pub/bar.rdf"

It's often a good idea to validate RDF before attempting to load it into a
store.

=head2 Quad Store Management

RDF::Trine stores can be connected to using DSN-like configuration strings
such as:

   DBI;mymodel;DBI:mysql:database=rdf;user;password

These configuration strings are passed to the App::perlrdf tool using the
'store' option:

   $ perlrdf make_store \
      --store="DBI;mymodel;DBI:mysql:database=rdf;user;password"

For the common case of DBI-backed stores, App::perlrdf offers the ability
to avoid configuration strings and just specify database type, name, etc:

   $ perlrdf make_store \
      --database=mysql \
      --dbname=rdf \
      --username=user \
      --password=password \
      --model=contacts_db

SQLite-backed stores are particularly easy to work with:

   $ perlrdf make_store --sqlite=/tmp/mydatabase.sqlite

If no store is specified on the command line, the C<PERLRDF_STORE>
environment variable is consulted.

	$ setenv PERLRDF_STORE "DBI;xyz;DBI:mysql:database=rdf;un;pw"
   $ perlrdf make_store

=head3 C<< perlrdf make_store >>

Initializes the store, creating empty data structures, etc.

If the store already exists this I<should> be non-destructive.

=head3 C<< perlrdf store_describe >>

Describes a resource in the database.

   $ perlrdf store_describe --sqlite=/tmp/mydatabase.sqlite \
      --output-format=RDFXML \
      "http://www.example.com/id/alice"

=head3 C<< perlrdf store_dump >>

Dumps the contents of a store to a FileSpec, or to STDOUT. As with the
C<translate> command, this may take multiple output filenames.

With the 'graph' option, you can limit the dump to specific graphs.

=head3 C<< perlrdf store_load >>

Loads one or more FileSpecs into the store. By default, data is loaded as
triples (in no graph). You can specify a graph URI for the data using the
'graph' option; or use the 'autograph' option to indicate that you wish to
use the FileSpec URIs as graph URIs.

=head3 C<< perlrdf store_truncate >>

Deletes all data from a store.

With the 'graph' option, you can delete specific graphs.

=head2 Other

=head3 C<< perlrdf isomorphic >>

Given two input FileSpecs, checks whether they are isomorphic (i.e. the same
graph after mapping blank node identifiers). If they are non-isomorphic, it
will also inform you about them differing in "interesting" ways - i.e. one
graph being an exact subgraph of the other.

=head3 C<< perlrdf prefix >>

Looks up one or more prefixes using RDF::NS.

   $ perlrdf prefix rdf,rdfs,owl,xsd
   owl     http://www.w3.org/2002/07/owl#
   rdf     http://www.w3.org/1999/02/22-rdf-syntax-ns#
   rdfs    http://www.w3.org/2000/01/rdf-schema#
   xsd     http://www.w3.org/2001/XMLSchema#

   $ perlrdf prefix --format=turtle foaf,dc
   @prefix dc: <http://purl.org/dc/elements/1.1/> .
   @prefix foaf: <http://xmlns.com/foaf/0.1/> .

=head1 SEE ALSO

L<RDF::Trine>,
L<RDF::TriN3>,
L<RDF::Query>,
L<RDF::Query::Client>,
L<RDF::NS>.

Find App::perlrdf plugins on MetaCPAN:
L<https://metacpan.org/search?q=App::perlrdf::Command>.

=head1 AUTHOR

Toby Inkster E<lt>tobyink@cpan.orgE<gt>.

=head1 COPYRIGHT AND LICENCE

This software is copyright (c) 2012 by Toby Inkster.

This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.

=head1 DISCLAIMER OF WARRANTIES

THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.