xmllint accepts the following options (in alphabetical order):

--auto

Generate a small document for testing purposes.

--catalogs

Use the catalogs from SGML_CATALOG_FILES. Otherwise /etc/xml/catalog is used by default.

--chkregister

Turn on node registration. Useful for developers testing (3) node tracking code.

--compress

Turn on gzip compression of output.

--copy

Test the internal copy implementation.

--c14n

Use the W3C XML Canonicalisation (C14N) to serialize the result of parsing to stdout. It keeps comments in the result.

--dtdvalid URL

Use the DTD specified by an URL for validation.

--dtdvalidfpi FPI

Use the DTD specified by a Public Identifier FPI for validation, note that this will require a Catalog exporting that Public Identifier to work.

--debug

Parse a file and output an annotated tree of the in-memory version of the document.

--debugent

Debug the entities defined in the document.

--dropdtd

Remove DTD from output.

--dtdattr

Fetch external DTD and populate the tree with inherited attributes.

--encode ENCODING

Output in the given encoding.

--format

Reformat and reindent the output. The XMLLINT_INDENT environment variable controls the indentation (default value is two spaces " ").

--help

Print out a short usage summary for xmllint.

--html

Use the HTML parser.

--htmlout

Output results as an HTML file. This causes xmllint to output the necessary HTML tags surrounding the result tree output so the results can be displayed/viewed in a browser.

--insert

Test for valid insertions.

--loaddtd

Fetch external DTD.

--load-trace

Display all the documents loaded during the processing to stderr.

--maxmem NNBYTES

Test the parser memory support. NNBYTES is the maximum number of bytes the library is allowed to allocate. This can also be used to make sure batch processing of XML files will not exhaust the virtual memory of the server running them.

--memory

Parse from memory.

--noblanks

Drop ignorable blank spaces.

--nocatalogs

Do not use any catalogs.

--nocdata

Substitute CDATA section by equivalent text nodes.

--noent

Substitute entity values for entity references. By default, xmllint leaves entity references in place.

--nonet

Do not use the Internet to fetch DTDs or entities.

--noout

Suppress output. By default, xmllint outputs the result tree.

--nowarning

Do not emit warnings from the parser and/or validator.

--nowrap

Do not output HTML doc wrapper.

--noxincludenode

Do XInclude processing but do not generate XInclude start and end nodes.

--nsclean

Remove redundant namespace declarations.

--output FILE

Define a file path where xmllint will save the result of parsing. Usually the programs build a tree and save it on stdout, with this option the result XML instance will be saved onto a file.

--path "PATH(S)"

Use the (space- or colon-separated) list of filesystem paths specified by PATHS to load DTDs or entities. Enclose space-separated lists by quotation marks.

--pattern PATTERNVALUE

Used to exercise the pattern recognition engine, which can be used with the reader interface to the parser. It allows to select some nodes in the document based on an XPath (subset) expression. Used for debugging.

--postvalid

Validate after parsing is completed.

--push

Use the push mode of the parser.

--recover

Output any parsable portions of an invalid document.

--relaxng SCHEMA

Use RelaxNG file named SCHEMA for validation.

--repeat

Repeat 100 times, for timing or profiling.

--schema SCHEMA

Use a W3C XML Schema file named SCHEMA for validation.

--shell

Run a navigating shell. Details on available commands in shell mode are below (see the section called lqSHELL COMMANDSrq).

--stream

Use streaming API - useful when used in combination with --relaxng or --valid options for validation of files that are too large to be held in memory.

--testIO

Test user input/output support.

--timing

Output information about the time it takes xmllint to perform the various steps.

--valid

Determine if the document is a valid instance of the included Document Type Definition (DTD). A DTD to be validated against also can be specified at the command line using the --dtdvalid option. By default, xmllint also checks to determine if the document is well-formed.

--version

Display the version of (3) used.

--walker

Test the walker module, which is a reader interface but for a document tree, instead of using the reader API on an unparsed document it works on a existing in-memory tree. Used in debugging.

--xinclude

Do XInclude processing.

--xmlout

Used in conjunction with --html. Usually when HTML is parsed the document is saved with the HTML serializer, but with this option the resulting document is saved with the XML serializer. This is primarily used to generate XHTML from HTML input.

xmllint offers an interactive shell mode invoked with the --shell command. Available commands in shell mode include (in alphabetical order):

base

Display XML base of the node.

bye

Leave the shell.

cat NODE

Display the given node or the current one.

cd PATH

Change the current node to the given path (if unique) or root if no argument is given.

dir PATH

Dumps information about the node (namespace, attributes, content).

du PATH

Show the structure of the subtree under the given path or the current node.

exit

Leave the shell.

help

Show this help.

free

Display memory usage.

load FILENAME

Load a new document with the given filename.

ls PATH

List contents of the given path or the current directory.

pwd

Display the path to the current node.

quit

Leave the shell.

save FILENAME

Save the current document to the given filename or to the original name.

validate

Check the document for errors.

write FILENAME

Write the current node to the given filename.

SGML_CATALOG_FILES

to be written ...

XML_CATALOG_FILES

Catalog behavior can be changed by redirecting queries to the user's own set of catalogs. This can be done by setting the XML_CATALOG_FILES environment variable to a list of catalogs. An empty one should deactivate loading the default /etc/xml/catalog default catalog.

XML_DEBUG_CATALOG

Setting the environment variable XML_DEBUG_CATALOG using the export command outputs debugging information related to catalog operations.

XMLLINT_INDENT

to be written ...

On the completion of execution, xmllint returns the following error codes:

0

No error

1

Unclassified

2

Error in DTD

3

Validation error

4

Validation error

5

Error in schema compilation

6

Error writing output

7

Error in pattern (generated when --pattern option is used)

8

Error in Reader registration (generated when --chkregister option is used)

9

Out of memory error

(3)