librasqal(3) [debian man page]
librasqal(3) Library Functions Manual librasqal(3) NAME
librasqal - Rasqal RDF query library SYNOPSIS
#include <rasqal.h> rasqal_world*world=rasqal_new_world(); rasqal_query_results *results; raptor_uri *base_uri=raptor_new_uri("http://example.org/foo"); rasqal_query *rq=rasqal_new_query(world,"rdql",NULL); const char *query_string="select * from <http://example.org/data.rdf>"; rasqal_query_prepare(rq,query_string,base_uri); results=rasqal_query_execute(rq); while(!rasqal_query_results_finished(results)) { for(i=0;i<rasqal_query_results_get_bindings_count(results);i++) { const char *name=rasqal_query_results_get_binding_name(results,i); rasqal_literal *value=rasqal_query_results_get_binding_value(results,i); /* ... */ } rasqal_query_results_next(results); } rasqal_free_query_results(results); rasqal_free_query(rq); raptor_free_uri(base_uri); rasqal_free_world(world); cc prog.c -o prog `pkg-config rasqal --cflags` `pkg-config rasqal --libs` DESCRIPTION
The Rasqal library provides a high-level interface to RDF query parsing, query construction, query execution over an RDF graph and query results manipulation and formatting. The library provides APIs to each of the steps in the process and provides support for handling mul- tiple query language syntaxes. At present Rasqal supports most of the W3C SPARQL 1.0 Query language, some of SPARQL 1.1 draft and fully supports RDQL. Rasqal uses the libraptor(3) library for providing URI handling, WWW content retrieval and other support functions. API REFERENCE
See the HTML API docs that may be installed system wide at /usr/share/gtk-doc/html/rasqal/ or on the web at http://librdf.org/rasqal/docs/api/ <http://librdf.org/rasqal/docs/api/> API CHANGES
See the Raptor API docs changes section at http://librdf.org/rasqal/docs/api/rasqal-changes.html <http://librdf.org/rasqal/docs/api/rasqal- changes.html> CONFORMING TO
SPARQL Query Language for RDF, Eric Prud'hommeaux and Andy Seaborne (eds), W3C Recommendation, 15 January 2008 http://www.w3.org/TR/2008/REC-rdf-sparql-query-20080115/ <http://www.w3.org/TR/2008/REC-rdf-sparql-query-20080115/> SPARQL Query Results XML Format, Jeen Broekstra and Dave Beckett (eds), W3C Recommendation, 15 January 2008. http://www.w3.org/TR/2008/REC-rdf-sparql-XMLres-20080115/ <http://www.w3.org/TR/2008/REC-rdf-sparql-XMLres-20080115/> RDQL - A Query Language for RDF, Andy Seaborne, W3C Member Submission 9 January 2004 http://www.w3.org/Submission/2004/SUBM-RDQL-20040109/ <http://www.w3.org/Submission/2004/SUBM-RDQL-20040109/> SEE ALSO
roqet(1),libraptor(3) AUTHOR
Dave Beckett - http://purl.org/net/dajobe/ <http://purl.org/net/dajobe/> 2011-01-12 librasqal(3)
Check Out this Related Man Page
roqet(1) General Commands Manual roqet(1) NAME
roqet - Rasqal RDF query utility SYNOPSIS
roqet [OPTIONS] <query-URI> [base-URI] roqet [OPTIONS]-e query-string [base-URI] roqet [OPTIONS]-p sparql-protocol-service-URI [-e query-string ] [base-URI] DESCRIPTION
The roqet utility allows querying of RDF content using the Rasqal RDF query library, printing the results in variable bindings, RDF graph or boolean format. The query is read from query-URI and the optional base-URI is used as the base URI of the query if present. MAIN OPTIONS
roqet uses the usual GNU command line syntax, with long options starting with two dashes (`-') if supported by the getopt_long function. Otherwise only the short options are available. -e, --exec QUERY Execute the query in the argument QUERY instead of reading the query from a URI (when -e / --exec is not given). -i, --input LANGUAGE Set the input query LANGUAGE to one of the supported languages which includes 'sparql' (SPARQL Query Language for RDF, default), 'sparql11', 'laqrs' and 'rdql' (RDF Data Query Language). The full list of supported languages and susbets is given in the help summary with the -h / --help option. -p, --protocol SERVICE-URI Call the SPARQL HTTP protocol SERVICE-URI to execute the query instead of executing it inside the Rasqal query engine locally. -r, --results FORMAT Set the query results format. For variable bindings, the values of FORMAT vary upon what Rasqal supports but include 'simple' for a simple text format (default), 'xml' for the SPARQL Query Results XML format, 'rdfxml' and 'turtle' for RDF syntax formats, and 'json' for a JSON version of the results. For RDF graph results, the values of FORMAT are 'ntriples' (N-Triples, default), 'rdfxml-abbrev' (RDF/XML Abbreviated), 'rdfxml' (RDF/XML), 'turtle' (Turtle), 'json' (RDF/JSON resource centric), 'json-triples' (RDF/JSON triples) or 'rss-1.0' (RSS 1.0, also an RDF/XML syntax). The exact list of formats depends on what libraptor2(3) was built with but is given correct in the usage message with -h. OTHER OPTIONS
-c, --count Only count the triples and produce no other output. -d, --dump-query FORMAT Print the parsed query out in a given FORMAT one of 'none' (default), 'debug', 'structure' or 'sparql' -D, --data URI Add RDF data source URI (not a named graph). If no data sources are given, the query itself must point to the data such as via SPARQL or RDQL FROM uri statements. -E, --ignore-errors Do not print error messages and do not exit with a non-0 status. -f, --feature NAME(=VALUE) Set query feature NAME to the VALUE or integer 1 if omitted. The known features can be shown with -f help or --feature help. -F, --format NAME Set the data source format name for subsequent data graphs called with -D / --data or -G / --named. The default if this is not specified is for the query engine to guess. The name is a Raptor parser name. -G, --named URI Add RDF data source URI (named graph) -h, --help Show a summary of the options. -n, --dryrun Prepare the query but do not execute it. -q, --quiet No extra information messages. -s, --source URI Add RDF data source URI (named graph) URI by adding it to the list of query data source URIs. FORMAT to 'simple' (default) or 'xml' (an experimental XML format) -v, --version Print the rasqal library version and exit. -W, --warnings LEVEL Set the warning LEVEL in the range 0 (do not warn about anything) to 100 (show every warning). The Rasqal default is in the middle (50). EXAMPLES
roqet sparql-query-file.rq Run a SPARQL query contained in the local file sparql-query-file.rq. The data used would be described in FROM statements in the query file. roqet -q -i sparql http://example.org/sparql-query.rq Run a SPARQL query that is in the web at URI http://example.org/sparql-query.rq without an extra messages (quiet, -q). roqet -q -i rdql rdql-query-file.rdql http://example.org/base/ Run an RDQL query from a local file rdql-query-file.rdql but using base URI http://example.org/base/ to resolve any relative URIs. roqet -q -i sparql -r xml http://example.org/sparql-query.rq Run a SPARQL query that is in the web at URI http://example.org/sparql-query.rq and format the results in the SPARQL Query Results XML for- mat with no extra messages. roqet -i sparql -e 'SELECT * WHERE { ?s ?p ?o }' -D stuff.rdf Run a SPARQL query given on the command line against data in the file stuff.rdf. The type of the file will be guessed and likely is of format RDF/XML. CONFORMING TO
SPARQL Query Language for RDF, Eric Prud'hommeaux and Andy Seaborne (eds), W3C Recommendation, 15 January 2008. http://www.w3.org/TR/2008/REC-rdf-sparql-query-20080115/ <http://www.w3.org/TR/2008/REC-rdf-sparql-query-20080115/> SPARQL Query Results XML Format, Jeen Broekstra and Dave Beckett (eds), W3C Recommendation, 15 January 2008. http://www.w3.org/TR/2008/REC-rdf-sparql-XMLres-20080115/ <http://www.w3.org/TR/2008/REC-rdf-sparql-XMLres-20080115/> RDQL - A Query Language for RDF, Andy Seaborne, W3C Member Submission 9 January 2004 http://www.w3.org/Submission/2004/SUBM-RDQL-20040109/ <http://www.w3.org/Submission/2004/SUBM-RDQL-20040109/> SEE ALSO
librasqal(3),libraptor(3) CHANGES
AUTHOR
Dave Beckett - http://www.dajobe.org/ <http://www.dajobe.org/> 2011-06-11 roqet(1)