RDF format converter

lodconvert.rb

#!/usr/bin/env ruby
#
# % gem install linkeddata
# % lodconvert.rb -h
# % lodconvert.rb [-i input_format] [-o output_format] inputfile > outputfile
#

require 'rubygems'
require 'linkeddata'
require 'getoptlong'

def help
  puts DATA.read
end

# Set default output format to turtle
opts = {
  :output => :ttl
}

args = GetoptLong.new(
  [ '--input',  '-i', GetoptLong::REQUIRED_ARGUMENT ],
  [ '--output', '-o', GetoptLong::REQUIRED_ARGUMENT ],
  [ '--help',   '-h', GetoptLong::NO_ARGUMENT ],
)

args.each_option do |name, value|
  case name
  when /--input/
    opts[:input] = value.to_sym
  when /--output/
    opts[:output] = value.to_sym
  when /--help/
    help
    exit 0
  end
end

if opts[:input]
  hash = { :format => opts[:input] }
else
  hash = {}
end

RDF::Graph.load(ARGV.shift, hash) do |graph|
  puts graph.dump(opts[:output], :standard_prefixes => true)
end

__END__
NAME
    lodconvert.rb -- RDF format converter

SYNOPSIS
    lodconvert.rb --help
    lodconvert.rb [--input format] --output format input_file > output_file

DESCRIPTION

    Accepted formats includes:

      rdf, rdfxml    RDF/XML
      ttl, turtle    Turtle
      ntriples       N-Triples
      jsonld         JSON-LD
      trig           TriG
      trix           TriX
      nquads         N-Quads