'\" t
.\"     Title: xmllint
.\"    Author: John Fleck <jfleck@inkstain.net>
.\" Generator: DocBook XSL Stylesheets vsnapshot <http://docbook.sf.net/>
.\"      Date: 11/04/2023
.\"    Manual: xmllint Manual
.\"    Source: libxml2
.\"  Language: English
.\"
.TH "XMLLINT" "1" "11/04/2023" "libxml2" "xmllint Manual"
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.\" -----------------------------------------------------------------
.SH "NAME"
xmllint \- command line XML tool
.SH "SYNOPSIS"
.HP \w'\fBxmllint\fR\ 'u
\fBxmllint\fR [\fB\-\-version\fR | \fB\-\-debug\fR | \fB\-\-quiet\fR | \fB\-\-shell\fR | \fB\-\-xpath\ "\fR\fB\fIXPath_expression\fR\fR\fB"\fR | \fB\-\-debugent\fR | \fB\-\-copy\fR | \fB\-\-recover\fR | \fB\-\-nodict\fR | \fB\-\-noent\fR | \fB\-\-noout\fR | \fB\-\-nonet\fR | \fB\-\-path\ "\fR\fB\fIPATH(S)\fR\fR\fB"\fR | \fB\-\-load\-trace\fR | \fB\-\-htmlout\fR | \fB\-\-nowrap\fR | \fB\-\-valid\fR | \fB\-\-postvalid\fR | \fB\-\-dtdvalid\ \fR\fB\fIURL\fR\fR | \fB\-\-dtdvalidfpi\ \fR\fB\fIFPI\fR\fR | \fB\-\-timing\fR | \fB\-\-output\ \fR\fB\fIFILE\fR\fR | \fB\-\-repeat\fR | \fB\-\-insert\fR | \fB\-\-compress\fR | \fB\-\-html\fR | \fB\-\-xmlout\fR | \fB\-\-push\fR | \fB\-\-memory\fR | \fB\-\-max\-ampl\ \fR\fB\fIINTEGER\fR\fR | \fB\-\-maxmem\ \fR\fB\fINBBYTES\fR\fR | \fB\-\-nowarning\fR | \fB\-\-noblanks\fR | \fB\-\-nocdata\fR | \fB\-\-format\fR | \fB\-\-encode\ \fR\fB\fIENCODING\fR\fR | \fB\-\-dropdtd\fR | \fB\-\-nsclean\fR | \fB\-\-testIO\fR | \fB\-\-catalogs\fR | \fB\-\-nocatalogs\fR | \fB\-\-auto\fR | \fB\-\-xinclude\fR | \fB\-\-noxincludenode\fR | \fB\-\-loaddtd\fR | \fB\-\-dtdattr\fR | \fB\-\-stream\fR | \fB\-\-walker\fR | \fB\-\-pattern\ \fR\fB\fIPATTERNVALUE\fR\fR | \fB\-\-chkregister\fR | \fB\-\-relaxng\ \fR\fB\fISCHEMA\fR\fR | \fB\-\-schema\ \fR\fB\fISCHEMA\fR\fR | \fB\-\-c14n\fR | \fB\-\-pedantic\fR] {\fIXML\-FILE(S)\fR... | \-}
.HP \w'\fBxmllint\fR\ 'u
\fBxmllint\fR \fB\-\-help\fR
.SH "DESCRIPTION"
.PP
The
\fBxmllint\fR
program parses one or more
XML
files, specified on the command line as
\fIXML\-FILE\fR
(or the standard input if the filename provided is
\fB\-\fR
)\&. 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
\fBxmllint\fR
is included in
\fBlibxml\fR(3)\&.
.SH "OPTIONS"
.PP
\fBxmllint\fR
accepts the following options (in alphabetical order):
.PP
\fB\-\-auto\fR
.RS 4
Generate a small document for testing purposes\&.
.RE
.PP
\fB\-\-catalogs\fR
.RS 4
Use the
SGML
catalog(s) from
\fBSGML_CATALOG_FILES\fR\&. Otherwise
XML
catalogs starting from
/etc/xml/catalog
or, more specifically,
${sysconfdir}/xml/catalog
are used by default\&.
.RE
.PP
\fB\-\-chkregister\fR
.RS 4
Turn on node registration\&. Useful for developers testing
\fBlibxml\fR(3)
node tracking code\&.
.RE
.PP
\fB\-\-compress\fR
.RS 4
Turn on
\fBgzip\fR(1)
compression of output\&.
.RE
.PP
\fB\-\-copy\fR
.RS 4
Test the internal copy implementation\&.
.RE
.PP
\fB\-\-c14n\fR
.RS 4
Use the W3C
XML
Canonicalisation (C14N) to serialize the result of parsing to
stdout\&. It keeps comments in the result\&.
.RE
.PP
\fB\-\-dtdvalid \fR\fB\fIURL\fR\fR
.RS 4
Use the
DTD
specified by an
\fIURL\fR
for validation\&.
.RE
.PP
\fB\-\-dtdvalidfpi \fR\fB\fIFPI\fR\fR
.RS 4
Use the
DTD
specified by a Formal Public Identifier
\fIFPI\fR
for validation, note that this will require a catalog exporting that Formal Public Identifier to work\&.
.RE
.PP
\fB\-\-debug\fR
.RS 4
Parse a file and output an annotated tree of the in\-memory version of the document\&.
.RE
.PP
\fB\-\-debugent\fR
.RS 4
Debug the entities defined in the document\&.
.RE
.PP
\fB\-\-dropdtd\fR
.RS 4
Remove
DTD
from output\&.
.RE
.PP
\fB\-\-dtdattr\fR
.RS 4
Fetch external
DTD
and populate the tree with inherited attributes\&.
.RE
.PP
\fB\-\-encode \fR\fB\fIENCODING\fR\fR
.RS 4
Output in the given encoding\&. Note that this works for full document not fragments or result from XPath queries\&.
.RE
.PP
\fB\-\-format\fR
.RS 4
Reformat and reindent the output\&. The
\fBXMLLINT_INDENT\fR
environment variable controls the indentation\&. The default value is two spaces " ")\&.
.RE
.PP
\fB\-\-help\fR
.RS 4
Print out a short usage summary for
\fBxmllint\fR\&.
.RE
.PP
\fB\-\-html\fR
.RS 4
Use the
HTML
parser\&.
.RE
.PP
\fB\-\-htmlout\fR
.RS 4
Output results as an
HTML
file\&. This causes
\fBxmllint\fR
to output the necessary
HTML
tags surrounding the result tree output so the results can be displayed/viewed in a browser\&.
.RE
.PP
\fB\-\-insert\fR
.RS 4
Test for valid insertions\&.
.RE
.PP
\fB\-\-loaddtd\fR
.RS 4
Fetch an external
DTD\&.
.RE
.PP
\fB\-\-load\-trace\fR
.RS 4
Display all the documents loaded during the processing to
stderr\&.
.RE
.PP
\fB\-\-max\-ampl \fR\fB\fIINTEGER\fR\fR
.RS 4
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
\fB\-\-maxmem \fR\fB\fINNBYTES\fR\fR
.RS 4
Test the parser memory support\&.
\fINNBYTES\fR
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
\fB\-\-memory\fR
.RS 4
Parse from memory\&.
.RE
.PP
\fB\-\-noblanks\fR
.RS 4
Drop ignorable blank spaces\&.
.RE
.PP
\fB\-\-nocatalogs\fR
.RS 4
Do not use any catalogs\&.
.RE
.PP
\fB\-\-nocdata\fR
.RS 4
Substitute CDATA section by equivalent text nodes\&.
.RE
.PP
\fB\-\-nodict\fR
.RS 4
Don\*(Aqt use dictionaries (parser option XML_PARSE_NODICT)\&. Only for debugging\&.
.RE
.PP
\fB\-\-noent\fR
.RS 4
Substitute entity values for entity references\&. By default,
\fBxmllint\fR
leaves entity references in place\&.
.RE
.PP
\fB\-\-nonet\fR
.RS 4
Do not use the Internet to fetch
DTDs or entities\&.
.RE
.PP
\fB\-\-noout\fR
.RS 4
Suppress output\&. By default,
\fBxmllint\fR
outputs the result tree\&.
.RE
.PP
\fB\-\-nowarning\fR
.RS 4
Do not emit warnings from the parser and/or validator\&.
.RE
.PP
\fB\-\-nowrap\fR
.RS 4
Do not output
HTML
doc wrapper\&.
.RE
.PP
\fB\-\-noxincludenode\fR
.RS 4
Do XInclude processing but do not generate XInclude start and end nodes\&.
.RE
.PP
\fB\-\-nsclean\fR
.RS 4
Remove redundant namespace declarations\&.
.RE
.PP
\fB\-\-output \fR\fB\fIFILE\fR\fR
.RS 4
Define a file path where
\fBxmllint\fR
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
\fB\-\-path "\fR\fB\fIPATH(S)\fR\fR\fB"\fR
.RS 4
Use the (space\- or colon\-separated) list of filesystem paths specified by
\fIPATHS\fR
to load
DTDs or entities\&. Enclose space\-separated lists by quotation marks\&.
.RE
.PP
\fB\-\-pattern \fR\fB\fIPATTERNVALUE\fR\fR
.RS 4
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
\fB\-\-pedantic\fR
.RS 4
Enable additional warnings\&.
.RE
.PP
\fB\-\-postvalid\fR
.RS 4
Validate after parsing has completed\&.
.RE
.PP
\fB\-\-push\fR
.RS 4
Use the push mode of the parser\&.
.RE
.PP
\fB\-\-quiet\fR
.RS 4
Don\*(Aqt print informational messages to stderr\&.
.RE
.PP
\fB\-\-recover\fR
.RS 4
Output any parsable portions of an invalid document\&.
.RE
.PP
\fB\-\-relaxng \fR\fB\fISCHEMA\fR\fR
.RS 4
Use RelaxNG file named
\fISCHEMA\fR
for validation\&.
.RE
.PP
\fB\-\-repeat\fR
.RS 4
Repeat 100 times, for timing or profiling\&.
.RE
.PP
\fB\-\-schema \fR\fB\fISCHEMA\fR\fR
.RS 4
Use a W3C
XML
Schema file named
\fISCHEMA\fR
for validation\&.
.RE
.PP
\fB\-\-shell\fR
.RS 4
Run a navigating shell\&. Details on available commands in shell mode are below (see
the section called \(lqSHELL COMMANDS\(rq)\&.
.RE
.PP
\fB\-\-xpath "\fR\fB\fIXPath_expression\fR\fR\fB"\fR
.RS 4
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 an error exit code will be returned\&.
.RE
.PP
\fB\-\-stream\fR
.RS 4
Use streaming
API
\- useful when used in combination with
\fB\-\-relaxng\fR
or
\fB\-\-valid\fR
options for validation of files that are too large to be held in memory\&.
.RE
.PP
\fB\-\-testIO\fR
.RS 4
Test user input/output support\&.
.RE
.PP
\fB\-\-timing\fR
.RS 4
Output information about the time it takes
\fBxmllint\fR
to perform the various steps\&.
.RE
.PP
\fB\-\-valid\fR
.RS 4
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
\fB\-\-dtdvalid\fR
option\&. By default,
\fBxmllint\fR
also checks to determine if the document is well\-formed\&.
.RE
.PP
\fB\-\-version\fR
.RS 4
Display the version of
\fBlibxml\fR(3)
used\&.
.RE
.PP
\fB\-\-walker\fR
.RS 4
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
\fB\-\-xinclude\fR
.RS 4
Do XInclude processing\&.
.RE
.PP
\fB\-\-xmlout\fR
.RS 4
Used in conjunction with
\fB\-\-html\fR\&. 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
.SH "SHELL COMMANDS"
.PP
\fBxmllint\fR
offers an interactive shell mode invoked with the
\fB\-\-shell\fR
command\&. Available commands in shell mode include (in alphabetical order):
.PP
\fBbase\fR
.RS 4
Display
XML
base of the node\&.
.RE
.PP
\fBbye\fR
.RS 4
Leave the shell\&.
.RE
.PP
\fBcat \fR\fB\fINODE\fR\fR
.RS 4
Display the given node or the current one\&.
.RE
.PP
\fBcd \fR\fB\fIPATH\fR\fR
.RS 4
Change the current node to the given path (if unique) or root if no argument is given\&.
.RE
.PP
\fBdir \fR\fB\fIPATH\fR\fR
.RS 4
Dumps information about the node (namespace, attributes, content)\&.
.RE
.PP
\fBdu \fR\fB\fIPATH\fR\fR
.RS 4
Show the structure of the subtree under the given path or the current node\&.
.RE
.PP
\fBexit\fR
.RS 4
Leave the shell\&.
.RE
.PP
\fBhelp\fR
.RS 4
Show this help\&.
.RE
.PP
\fBfree\fR
.RS 4
Display memory usage\&.
.RE
.PP
\fBload \fR\fB\fIFILENAME\fR\fR
.RS 4
Load a new document with the given filename\&.
.RE
.PP
\fBls \fR\fB\fIPATH\fR\fR
.RS 4
List contents of the given path or the current directory\&.
.RE
.PP
\fBpwd\fR
.RS 4
Display the path to the current node\&.
.RE
.PP
\fBquit\fR
.RS 4
Leave the shell\&.
.RE
.PP
\fBsave \fR\fB\fIFILENAME\fR\fR
.RS 4
Save the current document to the given filename or to the original name\&.
.RE
.PP
\fBvalidate\fR
.RS 4
Check the document for errors\&.
.RE
.PP
\fBwrite \fR\fB\fIFILENAME\fR\fR
.RS 4
Write the current node to the given filename\&.
.RE
.SH "ENVIRONMENT"
.PP
\fBSGML_CATALOG_FILES\fR
.RS 4
SGML
catalog behavior can be changed by redirecting queries to the user\*(Aqs own set of catalogs\&. This can be done by setting the
\fBSGML_CATALOG_FILES\fR
environment variable to a list of catalogs\&. An empty one should deactivate loading the default catalog\&.
.RE
.PP
\fBXML_CATALOG_FILES\fR
.RS 4
XML
catalog behavior can be changed by redirecting queries to the user\*(Aqs own set of catalogs\&. This can be done by setting the
\fBXML_CATALOG_FILES\fR
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
\fBXML_DEBUG_CATALOG\fR
.RS 4
Setting the environment variable
\fBXML_DEBUG_CATALOG\fR
to
\fInon\-zero\fR
using the
\fBexport\fR
command outputs debugging information related to catalog operations\&.
.RE
.PP
\fBXMLLINT_INDENT\fR
.RS 4
Setting the environment variable
\fBXMLLINT_INDENT\fR
controls the indentation\&. The default value is two spaces " "\&.
.RE
.SH "DIAGNOSTICS"
.PP
\fBxmllint\fR
return codes provide information that can be used when calling it from scripts\&.
.PP
\fB0\fR
.RS 4
No error
.RE
.PP
\fB1\fR
.RS 4
Unclassified
.RE
.PP
\fB2\fR
.RS 4
Error in
DTD
.RE
.PP
\fB3\fR
.RS 4
Validation error
.RE
.PP
\fB4\fR
.RS 4
Validation error
.RE
.PP
\fB5\fR
.RS 4
Error in schema compilation
.RE
.PP
\fB6\fR
.RS 4
Error writing output
.RE
.PP
\fB7\fR
.RS 4
Error in pattern (generated when
\fB\-\-pattern\fR
option is used)
.RE
.PP
\fB8\fR
.RS 4
Error in Reader registration (generated when
\fB\-\-chkregister\fR
option is used)
.RE
.PP
\fB9\fR
.RS 4
Out of memory error
.RE
.PP
\fB10\fR
.RS 4
XPath evaluation error
.RE
.SH "SEE ALSO"
.PP
\fBlibxml\fR(3)
.PP
More information can be found at
.sp
.RS 4
.ie n \{\
\h'-04'\(bu\h'+03'\c
.\}
.el \{\
.sp -1
.IP \(bu 2.3
.\}
\fBlibxml\fR(3)
web page
\m[blue]\fB\%https://gitlab.gnome.org/GNOME/libxml2\fR\m[]
.RE
.sp
.SH "AUTHORS"
.PP
\fBJohn Fleck\fR <\&jfleck@inkstain\&.net\&>
.RS 4
Author.
.RE
.PP
\fBZiying Sherwin\fR <\&sherwin@nlm\&.nih\&.gov\&>
.RS 4
Author.
.RE
.PP
\fBHeiko Rupp\fR <\&hwr@pilhuhn\&.de\&>
.RS 4
Author.
.RE
.SH "COPYRIGHT"
.br
Copyright \(co 2001, 2004
.br