.Dd October 21, 2021
.Dt SERD-VALIDATE 1
.Os Serd
.Sh NAME
.Nm serd-validate
.Nd validate RDF data
.Sh SYNOPSIS
.Nm serd-validate
.Op Fl hVv
.Op Fl B Ar base
.Op Fl I Ar syntax
.Op Fl W Ar checks
.Op Fl X Ar checks
.Op Fl k Ar bytes
.Op Fl s Ar schema
.Ar input ...
.Sh DESCRIPTION
.Nm
validates RDF data against one or more RDFS or OWL schemas.
Unlike other serd tools,
.Nm
does not write any data,
it only prints messages and returns a status that indicates whether the data is valid.
.Pp
All inputs to check must be given as an
.Ar input .
Schemas can also be given as an
.Ar input ,
in which case they will also be checked for issues.
Alternatively, schemas can be given using the
.Fl s
option, which will load the schema to check against,
but not initiate checks for schema statements themselves.
This roughly means that error messages will not be printed for the schema files,
although some may still appear if they are related to issues in the input files.
When using schemas in this way, it is highly recommended to ensure that the schemas are valid first,
otherwise the validator may not work correctly.
.Pp
The options are as follows:
.Pp
.Bl -tag -compact -width 3n
.It Fl B Ar base
Base URI or path.
See
.Xr serd-pipe 1
for details.
.Pp
.It Fl I Ar syntax
Input syntax or option:
.Cm NQuads ,
.Cm NTriples ,
.Cm TriG ,
.Cm Turtle ,
.Cm lax ,
.Cm variables ,
.Cm relative ,
or
.Cm labels .
See
.Xr serd-pipe 1
for details.
.Pp
.It Fl W Ar checks
Warn about any issues found by the given
.Ar checks ,
which is a regular expression that matches a set of check names to enable,
or a special name for standard sets of checks:
.Bl -tag -width 3n
.It Cm all
Enables all checks that should pass on typical well-formed data.
.It Cm everything
Enables all the checks of
.Cm all ,
along with additional strict checks that are useful for making data simpler and more explicit.
.El
.Pp
See
.Sx CHECKS
below for a detailed list of all checks.
.Pp
.It Fl X Ar checks
Exclude
.Ar checks
from the set of checks enabled by a previous
.Fl W
option.
This is typically used after
.Fl W Cm all
or
.Fl W Cm everything
to suppress a few specific checks.
.Pp
.It Fl V
Display version information and exit.
.Pp
.It Fl h
Print the command line options.
.Pp
.It Fl k Ar bytes
Parser stack size.
See
.Xr serd-pipe 1
for details.
.Pp
.It Fl s Ar schema
Schema input file.
The schema will be loaded like an input,
but into a separate graph that is not checked for issues.
.Pp
.It Fl v
Print verbose messages about loaded resources.
.El
.Sh CHECKS
.Bl -tag -compact -width 3n
.It Cm allValuesFrom
Checks that all properties with owl:allValuesFrom restrictions have valid value types.
.It Cm anyUri
Checks that the value of any property with range xsd:anyURI is a URI.
.It Cm cardinalityEqual
Checks that any instance of a class with a owl:cardinality property restriction has exactly that many values of that property.
.It Cm cardinalityMax
Checks that any instance of a class with a owl:maxCardinality property restriction has no more than that many values of that property.
.It Cm cardinalityMin
Checks that any instance of a class with a owl:minCardinality property restriction has at least that many values of that property.
.It Cm classCycle
Checks that no class is a sub-class of itself, recursively.
This ensures that the graph is acyclic with respect to rdfs:subClassOf.
If this check fails, all further checks are aborted.
.It Cm classLabel
Checks that every rdfs:Class has an rdfs:label.
.It Cm datatypeCycle
Checks that no datatype is a sub-datatype of itself, recursively.
This ensures that the graph is acyclic with respect to owl:onDatatype.
If this check fails, all further checks are aborted.
.It Cm datatypeProperty
Checks that datatype properties have literal (not instance) values.
.It Cm datatypeType
Checks that every datatype is defined as a rdfs:Datatype.
.It Cm deprecatedClass
Checks that there are no instances of deprecated classes.
.It Cm deprecatedProperty
Checks that there are no uses of deprecated properties.
.It Cm explicitInstanceType
Checks that every instance explicitly has every type required of it.
This is a (often overly) strict check that assumes a closed world and requires every instance to explicitly have the type(s) required of it.
.It Cm functionalProperty
Checks that no instance has several values of a functional property.
.It Cm instanceLiteral
Checks that there are no instances where a literal is expected.
.It Cm instanceType
Checks that every instance with an explicit type matches that type.
This is a broad check that triggers other type-related checks, but mainly it will check that every instance of a class conforms to any restrictions on that class.
.It Cm inverseFunctionalProperty
Checks that at most one instance has a given value of an inverse functional property.
.It Cm literalInstance
Checks that there are no literals where an instance is expected.
.It Cm literalMaxExclusive
Checks that literal values are not greater than or equal to any applicable xsd:maxExclusive datatype restrictions.
.It Cm literalMaxInclusive
Checks that literal values are not greater than any applicable xsd:maxInclusive datatype restrictions.
.It Cm literalMinExclusive
Checks that literal values are not less than or equal to any applicable xsd:minExclusive datatype restrictions.
.It Cm literalMinInclusive
Checks that literal values are not less than any applicable xsd:minInclusive datatype restrictions.
.It Cm literalPattern
Checks that literals with xsd:pattern restrictions match the regular expression pattern for their datatype.
.It Cm literalRestriction
Checks that literals with supported restrictions conform to those restrictions.
This is a high-level check that triggers the more specific individual literal restriction checks.
.It Cm literalValue
Checks that literals with supported XSD datatypes are valid.
The set of supported types is the same as when writing canonical forms.
.It Cm objectProperty
Checks that object properties have instance (not literal) values.
.It Cm plainLiteralDatatype
Checks that there are no typed literals where a plain literal is expected.
A plain literal may have an optional language tag, but not a datatype.
.It Cm predicateType
Checks that every predicate is defined as an rdf:Property.
.It Cm propertyCycle
Checks that no property is a sub-property of itself, recursively.
This ensures that the graph is acyclic with respect to rdfs:subPropertyOf.
If this check fails, all further checks are aborted.
.It Cm propertyDomain
Checks that any instance with a property with an rdfs:domain is in that domain.
.It Cm propertyLabel
Checks that every rdf:Property has an rdfs:label.
.It Cm propertyRange
Checks that the value for any property with an rdfs:range is in that range.
.It Cm someValuesFrom
Checks that instances of classes with owl:someValuesFrom property restrictions have at least one matching property value.
.El
.Sh EXIT STATUS
.Nm
exits with a status of 0 on success,
17 if the data is invalid,
or another non-zero status if an error occured.
.Sh EXAMPLES
To run all checks on a file:
.Pp
.Dl $ serd-validate -W all input.ttl
.Pp
To run only the
.Li classLabel
check on a file:
.Pp
.Dl $ serd-validate -W classLabel input.ttl
.Pp
To run all checks
.Em except
.Li classLabel
on a file:
.Pp
.Dl $ serd-validate -W all -X classLabel input.ttl
.Sh SEE ALSO
.Bl -item -compact
.It
.Xr serd-pipe 1
.It
.Xr serd-filter 1
.It
.Xr serd-sort 1
.It
.Lk http://drobilla.net/software/serd/
.El
.Sh STANDARDS
.Bl -item -compact
.It
.Rs
.%A W3C
.%T OWL 2 Web Ontology Language
.%D December 2012
.Re
.Lk https://www.w3.org/TR/owl2-syntax/
.It
.Rs
.%A W3C
.%D February 2014
.%T RDF Schema 1.1
.Re
.Lk https://www.w3.org/TR/rdf-schema/
.El
.Sh AUTHORS
.Nm
is a part of serd, by
.An David Robillard
.Mt d@drobilla.net .