XMLLINT(1)

NAME
xmllint - command line XML tool

SYNOPSIS
    .HP u
    xmllint
         [
             | --version
             | --debug
             | --quiet
             | --shell
             | --xpath "XPath_expression"
             | --xpath0 "XPath_expression"
             | --copy
             | --recover
             | --huge
             | --nocompact
             | --nodefdtd
             | --nodict
             | --noenc
             | --noent
             | --nofixup-base-uris
             | --noout
             | --nonet
             | --path "PATH(S)"
             | --load-trace
             | --valid
             | --postvalid
             | --dtdvalid URL
             | --dtdvalidfpi FPI
             | --timing
             | --output FILE
             | --repeat
             | --insert
             | --strict-namespace
             | --compress
             | --html
             | --xmlout
             | --push
             | --memory
             | --max-ampl INTEGER
             | --maxmem NBBYTES
             | --nowarning
             | --noblanks
             | --nocdata
             | --format
             | --pretty INTEGER
             | --encode ENCODING
             | --dropdtd
             | --nsclean
             | --catalogs
             | --nocatalogs
             | --auto
             | --xinclude
             | --noxincludenode
             | --loaddtd
             | --dtdattr
             | --stream
             | --walker
             | --pattern PATTERNVALUE
             | --relaxng SCHEMA
             | --schema SCHEMA
             | --schematron SCHEMA
             | --c14n
             | --c14n11
             | --exc-c14n
             | --pedantic
             | --sax
             | --sax1
             | --oldxml10
        ]
         {
             | XML-FILE(S)...
             | -
        }

DESCRIPTION

    .PP 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.
    .PP xmllint is part of the libxml2 library.

VALIDATION OPTIONS

    .PP Options enabling validation.

        .PP --dtdvalid URL

                    Use the DTD specified by an URL for validation.

            .RE
            .PP --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.

                .RE
                .PP --relaxng SCHEMA

                            Use RelaxNG file named SCHEMA for validation.

                    .RE
                    .PP --schema SCHEMA

                                Use a W3C XML Schema file named SCHEMA for validation.

                        .RE
                        .PP --schematron SCHEMA

                                    Use a Schematron file named SCHEMA for validation.

                            .RE
                            .PP --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.

                                .RE
                                .PP --strict-namespace

                                            Return an error if the document is well-formed, but has namespace errors. This enforces namespace-well-formedness.

                                    .RE

PARSER OPTIONS

    .PP The following options set the respective parser options.

        .PP --dtdattr

                    Fetch external DTD and populate the tree with inherited attributes. Implies --loaddtd.

            .RE
            .PP --huge

                        Ignore some hardcoded parser limits.

                .RE
                .PP --loaddtd

                            Fetch an external DTD and external parameter entities.

                    .RE
                    .PP --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.

                        .RE
                        .PP --noblanks

                                    Drop "ignorable" blank spaces. This option is unreliable and shouldn't be used.

                            .RE
                            .PP --nocatalogs

                                        Do not use any catalogs.

                                .RE
                                .PP --nocdata

                                            Substitute CDATA section by equivalent text nodes.

                                    .RE
                                    .PP --nodefdtd

                                                Do not set default HTML doctype (parser option HTML_PARSE_NODEFDTD).

                                        .RE
                                        .PP --noenc

                                                    Ignore encoding declaration (parser option XML_PARSE_IGNORE_ENC).

                                            .RE
                                            .PP --noent

                                                        Substitute entity values for entity references. By default, xmllint leaves entity references in place. This enables loading of external DTDs and entities.

                                                .RE
                                                .PP --nofixup-base-uris

                                                            Don't fix xml:base URIs when processing XIncludes (parser option XML_PARSE_NOBASEFIX).

                                                    .RE
                                                    .PP --nonet

                                                                Do not use the Internet to fetch DTDs or entities. Has no effect with libxml2 2.15 or later.

                                                        .RE
                                                        .PP --nowarning

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

                                                            .RE
                                                            .PP --nsclean

                                                                        Remove redundant namespace declarations.

                                                                .RE
                                                                .PP --oldxml10

                                                                            Use deprecated parsing rules before XML 1.0, 5th edition.

                                                                    .RE
                                                                    .PP --pedantic

                                                                                Enable additional warnings.

                                                                        .RE
                                                                        .PP --recover

                                                                                    Output any parsable portions of an invalid document. Exact behavior is unspecified. Use of this option is discouraged.

                                                                            .RE
                                                                            .PP --xinclude

                                                                                        Do XInclude processing.

                                                                                .RE

MISCELLANEOUS OPTIONS

    .PP Options that don't fall in another category.

        .PP --catalogs

                    Use the SGML catalog(s) from SGML_CATALOG_FILES. XML catalogs are loaded by default.

            .RE
            .PP --dropdtd

                        Remove DTD after parsing.

                .RE
                .PP --html

                            Use the HTML parser.

                    .RE
                    .PP --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.

                        .RE
                        .PP --quiet

                                    Don't print informational messages to stderr.

                            .RE
                            .PP --sax

                                        Print SAX callbacks for debugging. Can be used for streaming DTD and Schema validation when used with --noout.

                                .RE
                                .PP --shell

                                            Run a navigating shell. Details on available commands in shell mode are below (see the section called “SHELL COMMANDS”).

                                    .RE
                                    .PP --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.

                                        .RE
                                        .PP --version

                                                    Display the version of libxml2 used.

                                            .RE

OUTPUT OPTIONS

    .PP Options controlling output. Except for --noout these have no effect in SAX or stream mode.

        .PP --compress

                    Turn on gzip(1) compression of output.

            .RE
            .PP --c14n, --c14n11, --exc-c14n

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

                .RE
                .PP --encode ENCODING

                            Output in the given encoding. Note that this works for full document not fragments or result from XPath queries.

                    .RE
                    .PP --format

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

                                Especially in the absence of a DTD, this feature has never worked reliably and is fundamentally broken.

                        .RE
                        .PP --noout

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

                            .RE
                            .PP --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.

                                .RE
                                .PP --pretty INTEGER

                                            Value 0 means no formatting, 1 means XML_SAVE_FORMAT (same as --format), 2 means XML_SAVE_WSNONSIG.

                                    .RE
                                    .PP --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.

                                        .RE

DEBUG OPTIONS

    .PP The following options can be used to debug the libxml2 library. Behavior of these options may change without notice.

        .PP --auto

                    Generate a small document for testing purposes.

            .RE
            .PP --copy

                        Test the internal copy implementation.

                .RE
                .PP --debug

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

                    .RE
                    .PP --insert

                                Test for valid insertions. DEPRECATED: This feature will be removed.

                        .RE
                        .PP --load-trace

                                    Display all the documents loaded during the processing to stderr.

                            .RE
                            .PP --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.

                                .RE
                                .PP --memory

                                            Parse from memory.

                                    .RE
                                    .PP --nocompact

                                                Do not generate compact text nodes (parser option XML_PARSE_COMPACT). Only for debugging.

                                        .RE
                                        .PP --nodict

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

                                            .RE
                                            .PP --noxincludenode

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

                                                .RE
                                                .PP --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.

                                                    .RE
                                                    .PP --postvalid

                                                                Validate after parsing has completed.

                                                        .RE
                                                        .PP --push

                                                                    Use the push mode of the parser.

                                                            .RE
                                                            .PP --repeat

                                                                        Repeat 100 times, for timing or profiling.

                                                                .RE
                                                                .PP --sax1

                                                                            Use deprecated SAX1 interface (only for debugging).

                                                                    .RE
                                                                    .PP --timing

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

                                                                        .RE
                                                                        .PP --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.

                                                                            .RE
                                                                            .PP --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..

                                                                                .RE

SHELL COMMANDS

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

        .PP base

                    Display XML base of the node.

            .RE
            .PP bye

                        Leave the shell.

                .RE
                .PP cat NODE

                            Display the given node or the current one.

                    .RE
                    .PP cd PATH

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

                        .RE
                        .PP dir PATH

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

                            .RE
                            .PP du PATH

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

                                .RE
                                .PP exit

                                            Leave the shell.

                                    .RE
                                    .PP help

                                                Show this help.

                                        .RE
                                        .PP load FILENAME

                                                    Load a new document with the given filename.

                                            .RE
                                            .PP ls PATH

                                                        List contents of the given path or the current directory.

                                                .RE
                                                .PP pwd

                                                            Display the path to the current node.

                                                    .RE
                                                    .PP quit

                                                                Leave the shell.

                                                        .RE
                                                        .PP save FILENAME

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

                                                            .RE
                                                            .PP validate

                                                                        Check the document for errors.

                                                                .RE
                                                                .PP write FILENAME

                                                                            Write the current node to the given filename.

                                                                    .RE

ENVIRONMENT

        .PP 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.

            .RE
            .PP 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.

                .RE
                .PP XML_DEBUG_CATALOG

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

                    .RE
                    .PP XMLLINT_INDENT

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

                        .RE

DIAGNOSTICS

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

        .PP 0

                    No error

            .RE
            .PP 1

                        Unclassified

                .RE
                .PP 2

                            Error in DTD

                    .RE
                    .PP 3

                                Validation error

                        .RE
                        .PP 4

                                    Document isn't well-formed or couldn't be read

                            .RE
                            .PP 5

                                        Error in schema compilation

                                .RE
                                .PP 6

                                            Error writing output

                                    .RE
                                    .PP 7

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

                                        .RE
                                        .PP 9

                                                    Out of memory error

                                            .RE
                                            .PP 10

                                                        XPath evaluation error

                                                .RE
                                                .PP 11

                                                            XPath result is empty

                                                    .RE

SEE ALSO

    .PP More information can be found in the libxml2 repo at https://gitlab.gnome.org/GNOME/libxml2

AUTHORS

John Fleck <jfleck@inkstain.net>

Ziying Sherwin <sherwin@nlm.nih.gov>

Heiko Rupp <hwr@pilhuhn.de>

COPYRIGHT
Copyright © 2001, 2004