xmllint - Unix, Linux Command

previous next AddThis Social Bookmark Button


xmllint - command line XML tool


xmllint [--version --debug --shell --debugent --copy --recover --noent --noout --nonet --path "PATH(S)" --load-trace --htmlout --nowrap --valid --postvalid --dtdvalid URL --dtdvalidfpi FPI --timing --output FILE --repeat --insert --compress --html --xmlout --push --memory --maxmem NBBYTES --nowarning --noblanks --nocdata --format --encode ENCODING --dropdtd --nsclean --testIO --catalogs --nocatalogs --auto --xinclude --noxincludenode --loaddtd --dtdattr --stream --walker --pattern PATTERNVALUE --chkregister --relaxng SCHEMA --schema SCHEMA --c14n] {XML-FILE(S)... -}
xmllint --help


The xmllint program parses one or more XML files, specified on the command line as XML-FILE (or the standard input if the filename provided is - ). It prints various types of output, depending upon the options selected. It is useful for detecting errors both in XML code and in the XML parser itself.

xmllint is included in libxml(3).

More information can be found at

o libxml(3) web page  http://www.xmlsoft.org/
o W3C XSLT page  http://www.w3.org/TR/xslt


xmllint accepts the following options (in alphabetical order):

--auto Generate a small document for testing purposes.
  Use the catalogs from SGML_CATALOG_FILES. Otherwise /etc/xml/catalog is used by default.
  Turn on node registration. Useful for developers testing libxml(3) node tracking code.
  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.
  Debug the entities defined in the document.
  Remove DTD from output.
  Fetch external DTD and populate the tree with inherited attributes.
--encode ENCODING
  Output in the given encoding.
  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.
  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.
  Test for valid insertions.
  Fetch external DTD.
  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.
  Parse from memory.
  Drop ignorable blank spaces.
  Do not use any catalogs.
  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.
  Do not emit warnings from the parser and/or validator.
  Do not output HTML doc wrapper.
  Do XInclude processing but do not generate XInclude start and end nodes.
  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.
  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.
  Validate after parsing is completed.
--push Use the push mode of the parser.
  Output any parsable portions of an invalid document.
--relaxng SCHEMA
  Use RelaxNG file named SCHEMA for validation.
  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 COMMANDS\(rq).
  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.
  Test user input/output support.
  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.
  Display the version of libxml(3) used.
  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.
  Do XInclude processing.
  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.
  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).
  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 a new document with the given filename.
  List contents of the given path or the current directory.
pwd Display the path to the current node.
quit Leave the shell.
  Save the current document to the given filename or to the original name.
  Check the document for errors.
  Write the current node to the given filename.


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




John Fleck <jfleck@inkstain.net>, Ziying Sherwin <sherwin@nlm.nih.gov>, Heiko Rupp <hwr@pilhuhn.de>.
previous next Printer Friendly