Catmandu::Importer::RDF - parse RDF data
Command line client catmandu:
catmandu
catmandu convert RDF --url http://d-nb.info/gnd/4151473-7 to YAML catmandu convert RDF --file rdfdump.ttl to JSON # Parse the input into on JSON document per triplet. This is the # most memory efficient (and fastest) way to parse RDF input. catmandu convert RDF --triples 1 --file rdfdump.ttl to JSON # Transform back into NTriples (conversions to and from triples is the # most efficient way to process RDF) catmandu convert RDF --triples 1 --file rdfdump.ttl to RDF --type NTriples # Query a SPARQL endpoint catmandu convert RDF --url http://dbpedia.org/sparql --sparql "SELECT ?film WHERE { ?film dct:subject <http://dbpedia.org/resource/Category:French_films> }" catmandu convert RDF --url http://example.org/sparql --sparql query.rq # Query a Linked Data Fragment endpoint catmandu convert RDF --url http://fragments.dbpedia.org/2014/en --sparql "SELECT ?film WHERE { ?film dct:subject <http://dbpedia.org/resource/Category:French_films> }"
In Perl code:
use Catmandu::Importer::RDF; my $url = "http://dx.doi.org/10.2474/trol.7.147"; my $rdf = Catmandu::Importer::RDF->new( url => $url )->first;
This Catmandu::Importer can be use to import RDF data from URLs, files or input streams, SPARQL endpoints, and Linked Data Fragment endpoints.
By default an RDF graph is imported as single item in aREF format (see RDF::aREF).
URL to retrieve RDF from.
RDF serialization type (e.g. ttl for RDF/Turtle).
ttl
Base URL. By default derived from the URL or file name.
Use default namespace prefixes as provided by RDF::NS to abbreviate predicate and datatype URIs. Set to 0 to disable abbreviating URIs. Set to a specific date to get stable namespace prefix mappings.
0
Import each RDF triple as one aREF subject map (default) or predicate map (option predicate_map), if enabled. This is the most efficient way to process large input files. All the processing can be streamed.
predicate_map
Import RDF as aREF predicate map, if possible.
Default configuration options of Catmandu::Importer.
The SPARQL query to be executed on the URL endpoint (currectly only SELECT is supported). The query can be supplied as string or as filename. The importer tries to automatically add missing PREFIX statements from the default namespace prefixes.
Encoding of SPARQL result values. With aref, query results are encoded in aREF format, with URIs in < and > (no qNames) and literal nodes appended by @ and optional language code. By default (value simple), all RDF nodes are simplfied to their literal form.
aref
<
>
@
simple
Set to a true value to cache repeated URL responses in a CHI based backend.
Provide the CHI based options for caching result sets. By default a memory store of 1MB size is used. This is equal to:
Catamandu::Importer::RDF->new( ..., cache => 1, cache_options => { driver => 'Memory', global => 1, max_size => 1024*1024 });
If set to a true value, then write RDF file processing speed on the STDERR as number of triples parsed per second.
See Catmandu::Importer.
RDF::Trine::Store, RDF::Trine::Parser
To install Catmandu::RDF, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Catmandu::RDF
CPAN shell
perl -MCPAN -e shell install Catmandu::RDF
For more information on module installation, please visit the detailed CPAN module installation guide.