XMLLINT(1)

NAME
xmllint - command line XML tool

SYNOPSIS

xmllint [--version | --debug | --quiet | --shell | --xpath "XPath_expression" | --debugent | --copy | --recover | --nodict | --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 | --max-ampl INTEGER | --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 | --pedantic] {XML-FILE(S)... | -}

xmllint --help

DESCRIPTION

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).

OPTIONS

xmllint accepts the following options (in alphabetical order):

--auto
    Generate a small document for testing purposes.

--catalogs
    Use the SGML catalog(s) from SGML_CATALOG_FILES. Otherwise XML catalogs starting from /etc/xml/catalog or, more specifically, ${sysconfdir}/xml/catalog are used by default.

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

--compress
    Turn on gzip(1) 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 Formal Public Identifier FPI for validation, note that this will require a catalog exporting that Formal 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. Note that this works for full document not fragments or result from XPath queries.

--format
    Reformat and reindent the output. The XMLLINT_INDENT environment variable controls the indentation. The 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 an external DTD.

--load-trace
    Display all the documents loaded during the processing to stderr.

--max-ampl INTEGER
    Set the maximum amplification factor which protects against exponential entity expansion ("billion laughs"). The default value is 5. Documents making heavy use of entity expansion may require a higher value.

--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.

--nodict
    Don't use dictionaries (parser option XML_PARSE_NODICT). Only for debugging.

--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.

--pedantic
    Enable additional warnings.

--postvalid
    Validate after parsing has completed.

--push
    Use the push mode of the parser.

--quiet
    Don't print informational messages to stderr.

--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 “SHELL COMMANDS”).

--xpath "XPath_expression"
    Run an XPath expression given as argument and print the result. In case of a nodeset result, each node in the node set is serialized in full in the output. In case of an empty node set the "XPath set is empty" result will be shown and exit code 11 will be returned.. This feature is EXPERIMENTAL. Implementation details can change without futher notice.

--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 libxml(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 an existing in-memory tree. Used for 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.

SHELL COMMANDS

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.

ENVIRONMENT

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

XML_CATALOG_FILES
    XML 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 space-separated list of catalogs. Use percent-encoding to escape spaces or other characters. An empty variable should deactivate loading the default catalog.

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

XMLLINT_INDENT
    Setting the environment variable XMLLINT_INDENT controls the indentation. The default value is two spaces " ".

DIAGNOSTICS

xmllint return codes provide information that can be used when calling it from scripts.

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

10
    XPath evaluation error

11
    XPath result is empty

SEE ALSO

libxml(3)

More information can be found at

    • libxml(3) web page https://gitlab.gnome.org/GNOME/libxml2

AUTHORS

John Fleck <jfleck@inkstain.net>
    Author.

Ziying Sherwin <sherwin@nlm.nih.gov>
    Author.

Heiko Rupp <hwr@pilhuhn.de>
    Author.

COPYRIGHT
Copyright © 2001, 2004