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]  [ -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 stdin.

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

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

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

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

    o All elements nest properly.

    o All attribute  values  are enclosed in quotes (either single or dou-
  ble).

    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 separate ("d output") or mashed ("-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 file.

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

    The output filenames will be exactly the same as the input file-
    names or "STDIN" if the input is coming from STDIN.  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 equiva-
    lently 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 has 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 the input file, including character postitions. Requires -d
    to specify an output file.

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

    -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. -r
    turns off memory-mapping and uses normal file IO calls instead.
    Of course, memory-mapping is automatically turned off when read-
    ing from STDIN.

    -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, and then
    exits.

    -w   Enables 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)

    --   For some  reason, xmlwf  specifically ignores "--" anywhere it
    appears on the command line.

    Older versions of xmlwf do not support reading from STDIN.

OUTPUT
    If an input file is not  well-formed, xmlwf outputs a single line
    describing the problem to STDOUT. If a file is well formed, xmlwf out-
    puts nothing. Note that the result code is not set.

BUGS
    According to the W3C standard, an XML file without a declaration at the
    beginning is not considered well-formed.  However, xmlwf allows this to
    pass.

    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 STDOUT.

    The errors should go to STDERR, not stdout.

    There should be a way to get -d to send its output to STDOUT 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