---
name: "rapper"
section: "1"
platform: "linux"
package: "raptor"
version: "2.0.16-9"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/rapper"
---

# rapper(1)

Raptor RDF parsing and serializing utility

## NAME

rapper - Raptor RDF parsing and serializing utility

## SYNOPSIS

**rapper** \[**OPTIONS**\] *INPUT-URI* *\[INPUT-BASE-URI\]*

## EXAMPLE

```
rapper -o ntriples http://planetrdf.com/guide/rss.rdf
rapper -i rss-tag-soup -o rss-1.0 pile-of-rss.xml http://example.org/base/
rapper --count http://example.org/index.rdf
```

## DESCRIPTION

The **rapper** utility allows parsing of RDF content by the **Raptor** RDF parser toolkit emitting the results as RDF triples in a choice of syntaxes.  The *INPUT-URI* can be a file name, '-' for standard input or if Raptor is built with a WWW retrieval library, a general URI.  The optional *INPUT-BASE-URI* is used as the document parser base URI if present otherwise defaults to the *INPUT-URI*. A value of '-' means no base URI.

## OPTIONS

rapper uses the usual GNU command line syntax, with long options starting with two dashes (\`-') if supported by the getopt\_long function.  Otherwise the short options are only available.

- **-h, --help**

  Show a summary of the options.

- **-i, --input FORMAT**

  Set the input *FORMAT* to one of 'rdfxml' (RDF/XML, default), 'ntriples' (N-Triples, see below), 'turtle' (Turtle, see below) or 'rss-tag-soup' (RSS Tag Soup).  The RSS Tag Soup parser can turn the many XML RSS formats, Atom 0.3 and Atom 1.0 into RDF triples.

-

  The list of parsers depends on how [libraptor(3)](/libraptor/3.md) was built.  The list of supported parsers is given in the help summary given by -h.

- **-I, --input-uri URI**

  Set the input/parser base *URI* or use value '-' for no base. The default is the INPUT-URI argument value.

- **-o, --output FORMAT**

  Set the output *FORMAT* to 'ntriples' (N-Triples, default), 'rdfxml' (RDF/XML), 'rdfxml-abbrev' (RDF/XML with abbreviations) or 'rss-1.0' (RSS 1.0, also an RDF/XML syntax).

-

  The list of serializers depends on how [libraptor(3)](/libraptor/3.md) was built.  The list of supported serializers is given in the help summary given by -h.

- **-O, --output-uri URI**

  Set the output/serializer base *URI* or use value '-' for no base. The default is the input base uri, either set by the argument INPUT-BASE-URI or via options **-I, --input-uri URI**

- **-c, --count**

  Only count the triples and produce no other output.

- **-e, --ignore-errors**

  Ignore errors, do not emit the messages and try to continue parsing.

- **-f, --feature FEATURE\[=VALUE\]**

  Set a parser or serializer feature *FEATURE* to a value, or to 1 if *VALUE* is omitted, Use -f help to get lists of valid parser and serializer features.

-

  If the form -f 'xmlns:*prefix*="*uri*"' is used, the prefix and namespace uri given will be set for serializing. The syntax matches XML in that either or both of *prefix* or *uri* can be omitted.

- **-g, --guess**

  Guess the parser to use from the source-URI rather than use the -i FORMAT.

- **-q, --quiet**

  No extra information messages.

- **-r, --replace-newlines**

  Replace newlines in multi-line literals with spaces.

- **--show-graphs**

  Print graph names (URIs) as they are seen in the input.  This only has a meaning for parsers that support graph names such as the TRiG parser.

- **--show-namespaces**

  Print namespaces as they are seen in the input.

- **-t, --trace**

  Print URIs retrieved during parsing.  Especially useful for  monitoring what the guess and GRDDL parsers are doing.

- **-w, --ignore-warnings**

  Ignore warnings, do not emit the messages.

- **-v, --version**

  Print the raptor version and exit.

## EXAMPLES

**rapper -q -i ntriples -o rdfxml -f 'xmlns:rss="http://purl.org/rss/1.0/"' -f 'xmlns:ex="http://example.org/"' tests/test.nt**\
 **rapper -q -o rdfxml -f 'xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"' tests/rdf-schema.rdf 'http://www.w3.org/2000/01/rdf-schema#'**

## CONFORMING TO

*RDF/XML Syntax (Revised)*, W3C Recommendation, http://www.w3.org/TR/rdf-syntax-grammar/ ⟨http://www.w3.org/TR/rdf-syntax-grammar/⟩

*N-Triples*, in *RDF Test Cases*, Jan Grant and Dave Beckett (eds.), W3C Recommendation, http://www.w3.org/TR/rdf-testcases/#ntriples ⟨http://www.w3.org/TR/rdf-testcases/#ntriples⟩

*Turtle Terse RDF Triple Language*, Dave Beckett, http://www.dajobe.org/2004/01/turtle/ ⟨http://www.dajobe.org/2004/01/turtle/⟩

*RDFA in XHTML: Syntax and Processing*, Ben Adida, Mark Birbeck, Shane McCarron and Steven Pemberton (eds.), W3C Candidate Recommendation, 20 June 2008 http://www.w3.org/TR/2008/CR-rdfa-syntax-20080620/ ⟨http://www.w3.org/TR/2008/CR-rdfa-syntax-20080620/⟩

*RDF Site Summary (RSS) 1.0*, 2000-12-06 http://purl.org/rss/1.0/spec ⟨http://purl.org/rss/1.0/spec⟩

## SEE ALSO

**[libraptor(3)](/libraptor/3.md),**[raptor-config(1)](/raptor-config/1.md)

## CHANGES

### 2.0.0

Removed -a option that did nothing.

Removed -m option from rapper but it was never documented here.

Removed -n option that was long hidden.

Removed -s option that was equivalent to -f scanForRDF

### 1.4.16

Added -I/--input-uri and -O/--output-uri to set the input and output (parser and serializer) base URIs separately.

### 1.4.15

Added -t/--trace to do URI traces.

### 1.4.5

Updated to add serializer rdfxml-abbrev

### 1.4.3

Updated potential parser and serializers and described -f for defining namespaces.

### 1.3.0

Added -f for features.\
 Added -g for guessing the parser to use.

### 1.1.0

Removed -a, --assume since rdf:RDF is now always optional.\

## AUTHOR

Dave Beckett -  http://www.dajobe.org/ ⟨http://www.dajobe.org/⟩\