Ubuntu Manpage: xmlwf - Determines if an XML document is well-formed

Provided by: expat_2.2.9-1ubuntu0.8_amd64

NAME

       xmlwf - Determines if an XML document is well-formed

SYNOPSIS

       xmlwf [-s] [-n] [-p] [-x] [-e encoding] [-w] [-d output-dir] [-c] [-m] [-r] [-t] [-N] [-v] [file ...]

DESCRIPTION

       xmlwf uses the Expat library to determine if an XML document is well-formed. It is non-validating.

       If  you  do  not specify any files on the command-line, and you have a recent version of xmlwf, the input
       file will be read from standard input.

WELL-FORMED DOCUMENTS

       A well-formed document must adhere to the following rules:

       • The file begins with an XML declaration. For instance, <?xml version="1.0"  standalone="yes"?>.   NOTE:
         xmlwf does not currently check for a valid XML declaration.

       • Every start tag is either empty (<tag/>) or has a corresponding end tag.

       • There  is  exactly one root element. This element must contain all other elements in the document. Only
         comments, white space, and processing instructions may come after the close of the root element.

       • All elements nest properly.

       • All attribute values are enclosed in quotes (either single or double).

       If the document has a DTD, and it strictly complies with that DTD, then the document is  also  considered
       valid.   xmlwf is a non-validating parser -- it does not check the DTD. However, it does support external
       entities (see the -x option).

OPTIONS

When an option includes an argument, you may specify the argument either separately ("-d output") or
concatenated with the option ("-doutput"). xmlwf supports both.

-c If the input file is well-formed and xmlwf doesn't encounter any errors, the input file is simply
copied to the output directory unchanged. This implies no namespaces (turns off -n) and requires
-d to specify an output directory.

-d output-dir
Specifies a directory to contain transformed representations of the input files. By default, -d
outputs a canonical representation (described below). You can select different output formats
using -c, -m and -N.

The output filenames will be exactly the same as the input filenames or "STDIN" if the input is
coming from standard input. Therefore, you must be careful that the output file does not go into
the same directory as the input file. Otherwise, xmlwf will delete the input file before it
generates the output file (just like running cat < file > file in most shells).

Two structurally equivalent XML documents have a byte-for-byte identical canonical XML
representation. Note that ignorable white space is considered significant and is treated
equivalently to data. More on canonical XML can be found at
http://www.jclark.com/xml/canonxml.html .

-e encoding
Specifies the character encoding for the document, overriding any document encoding declaration.
xmlwf supports four built-in encodings: US-ASCII, UTF-8, UTF-16, and ISO-8859-1. Also see the -w
option.

-m Outputs some strange sort of XML file that completely describes the input file, including
character positions. Requires -d to specify an output file.

-n Turns on namespace processing. (describe namespaces) -c disables namespaces.

-N Adds a doctype and notation declarations to canonical XML output. This matches the example output
used by the formal XML test cases. Requires -d to specify an output file.

-p Tells xmlwf to process external DTDs and parameter entities.

Normally xmlwf never parses parameter entities. -p tells it to always parse them. -p implies -x.

-r Normally xmlwf memory-maps the XML file before parsing; this can result in faster parsing on many
platforms. -r turns off memory-mapping and uses normal file IO calls instead. Of course, memory-
mapping is automatically turned off when reading from standard input.

Use of memory-mapping can cause some platforms to report substantially higher memory usage for
xmlwf, but this appears to be a matter of the operating system reporting memory in a strange way;
there is not a leak in xmlwf.

-s Prints an error if the document is not standalone. A document is standalone if it has no external
subset and no references to parameter entities.

-t Turns on timings. This tells Expat to parse the entire file, but not perform any processing. This
gives a fairly accurate idea of the raw speed of Expat itself without client overhead. -t turns
off most of the output options (-d, -m, -c, ...).

-v Prints the version of the Expat library being used, including some information on the compile-time
configuration of the library, and then exits.

-w Enables support for Windows code pages. Normally, xmlwf will throw an error if it runs across an
encoding that it is not equipped to handle itself. With -w, xmlwf will try to use a Windows code
page. See also -e.

-x Turns on parsing external entities.

Non-validating parsers are not required to resolve external entities, or even expand entities at
all. Expat always expands internal entities (?), but external entity parsing must be enabled
explicitly.

External entities are simply entities that obtain their data from outside the XML file currently
being parsed.

This is an example of an internal entity:

<!ENTITY vers '1.0.2'>

And here are some examples of external entities:

<!ENTITY header SYSTEM "header-&vers;.xml"> (parsed)
<!ENTITY logo SYSTEM "logo.png" PNG> (unparsed)

-- (Two hyphens.) Terminates the list of options. This is only needed if a filename starts with a
hyphen. For example:

xmlwf -- -myfile.xml

will run xmlwf on the file -myfile.xml.

Older versions of xmlwf do not support reading from standard input.

OUTPUT

       If  an  input  file  is  not  well-formed,  xmlwf prints a single line describing the problem to standard
       output. If a file is well formed, xmlwf outputs nothing.  Note that the result code is not set.

BUGS

       xmlwf returns a 0 - noerr result, even if the file is not well-formed. There is no good way for a program
       to use xmlwf to quickly check a file -- it must parse xmlwf's standard output.

       The errors should go to standard error, not standard output.

       There  should  be  a  way to get -d to send its output to standard output rather than forcing the user to
       send it to a file.

       I have no idea why anyone would want to use the -d, -c, and -m options. If someone could  explain  it  to
       me, I'd like to add this information to this manpage.

ALTERNATIVES

       Here are some XML validators on the web:

       http://www.hcrc.ed.ac.uk/~richard/xml-check.html
       http://www.stg.brown.edu/service/xmlvalid/
       http://www.scripting.com/frontier5/xml/code/xmlValidator.html
       http://www.xml.com/pub/a/tools/ruwf/check.html

AUTHOR

       This  manual page was written by Scott Bronson <bronson@rinspin.com> for the Debian GNU/Linux system (but
       may be used by others). Permission is granted to copy, distribute and/or modify this document  under  the
       terms of the GNU Free Documentation License, Version 1.1.

                                                 March 11, 2016                                         XMLWF(1)