src/expat/doc/xmlwf.sgml

   1 <!doctype refentry PUBLIC "-//OASIS//DTD DocBook V4.1//EN" [
   2
   3 <!-- Process this file with docbook-to-man to generate an nroff manual
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   8 manpage.1: manpage.sgml
   9         docbook-to-man $< > $@
  10   -->
  11
  12   <!-- Fill in your name for FIRSTNAME and SURNAME. -->
  13   <!ENTITY dhfirstname "<firstname>Scott</firstname>">
  14   <!ENTITY dhsurname   "<surname>Bronson</surname>">
  15   <!-- Please adjust the date whenever revising the manpage. -->
  16   <!ENTITY dhdate      "<date>December  5, 2001</date>">
  17   <!-- SECTION should be 1-8, maybe w/ subsection other parameters are
  18        allowed: see man(7), man(1). -->
  19   <!ENTITY dhsection   "<manvolnum>1</manvolnum>">
  20   <!ENTITY dhemail     "<email>bronson@rinspin.com</email>">
  21   <!ENTITY dhusername  "Scott Bronson">
  22   <!ENTITY dhucpackage "<refentrytitle>XMLWF</refentrytitle>">
  23   <!ENTITY dhpackage   "xmlwf">
  24
  25   <!ENTITY debian      "<productname>Debian GNU/Linux</productname>">
  26   <!ENTITY gnu         "<acronym>GNU</acronym>">
  27 ]>
  28
  29 <refentry>
  30   <refentryinfo>
  31     <address>
  32       &dhemail;
  33     </address>
  34     <author>
  35       &dhfirstname;
  36       &dhsurname;
  37     </author>
  38     <copyright>
  39       <year>2001</year>
  40       <holder>&dhusername;</holder>
  41     </copyright>
  42     &dhdate;
  43   </refentryinfo>
  44   <refmeta>
  45     &dhucpackage;
  46
  47     &dhsection;
  48   </refmeta>
  49   <refnamediv>
  50     <refname>&dhpackage;</refname>
  51
  52     <refpurpose>Determines if an XML document is well-formed</refpurpose>
  53   </refnamediv>
  54   <refsynopsisdiv>
  55     <cmdsynopsis>
  56       <command>&dhpackage;</command>
  57           <arg><option>-s</option></arg>
  58           <arg><option>-n</option></arg>
  59           <arg><option>-p</option></arg>
  60           <arg><option>-x</option></arg>
  61
  62           <arg><option>-e <replaceable>encoding</replaceable></option></arg>
  63           <arg><option>-w</option></arg>
  64
  65           <arg><option>-d <replaceable>output-dir</replaceable></option></arg>
  66           <arg><option>-c</option></arg>
  67           <arg><option>-m</option></arg>
  68
  69           <arg><option>-r</option></arg>
  70           <arg><option>-t</option></arg>
  71
  72           <arg><option>-v</option></arg>
  73
  74           <arg>file ...</arg>
  75     </cmdsynopsis>
  76   </refsynopsisdiv>
  77
  78   <refsect1>
  79     <title>DESCRIPTION</title>
  80
  81     <para>
  82         <command>&dhpackage;</command> uses the Expat library to
  83         determine if an XML document is well-formed.  It is
  84         non-validating.
  85         </para>
  86
  87         <para>
  88         If you do not specify any files on the command-line, and you
  89         have a recent version of <command>&dhpackage;</command>, the
  90         input file will be read from standard input.
  91         </para>
  92
  93   </refsect1>
  94
  95   <refsect1>
  96     <title>WELL-FORMED DOCUMENTS</title>
  97
  98         <para>
  99           A well-formed document must adhere to the
 100           following rules:
 101         </para>
 102
 103         <itemizedlist>
 104       <listitem><para>
 105             The file begins with an XML declaration.  For instance,
 106                 <literal>&lt;?xml version="1.0" standalone="yes"?&gt;</literal>.
 107                 <emphasis>NOTE:</emphasis>
 108                 <command>&dhpackage;</command> does not currently
 109                 check for a valid XML declaration.
 110       </para></listitem>
 111       <listitem><para>
 112                 Every start tag is either empty (&lt;tag/&gt;)
 113                 or has a corresponding end tag.
 114       </para></listitem>
 115       <listitem><para>
 116             There is exactly one root element.  This element must contain
 117                 all other elements in the document.  Only comments, white
 118                 space, and processing instructions may come after the close
 119                 of the root element.
 120       </para></listitem>
 121       <listitem><para>
 122                 All elements nest properly.
 123       </para></listitem>
 124       <listitem><para>
 125                 All attribute values are enclosed in quotes (either single
 126                 or double).
 127       </para></listitem>
 128     </itemizedlist>
 129
 130         <para>
 131           If the document has a DTD, and it strictly complies with that
 132           DTD, then the document is also considered <emphasis>valid</emphasis>.
 133           <command>&dhpackage;</command> is a non-validating parser --
 134           it does not check the DTD.  However, it does support
 135           external entities (see the <option>-x</option> option).
 136         </para>
 137   </refsect1>
 138
 139   <refsect1>
 140     <title>OPTIONS</title>
 141
 142 <para>
 143 When an option includes an argument, you may specify the argument either
 144 separately ("<option>-d</option> output") or concatenated with the
 145 option ("<option>-d</option>output").  <command>&dhpackage;</command>
 146 supports both.
 147 </para>
 148
 149     <variablelist>
 150
 151       <varlistentry>
 152         <term><option>-c</option></term>
 153         <listitem>
 154                 <para>
 155   If the input file is well-formed and <command>&dhpackage;</command>
 156   doesn't encounter any errors, the input file is simply copied to
 157   the output directory unchanged.
 158   This implies no namespaces (turns off <option>-n</option>) and
 159   requires <option>-d</option> to specify an output file.
 160                 </para>
 161         </listitem>
 162       </varlistentry>
 163
 164       <varlistentry>
 165         <term><option>-d output-dir</option></term>
 166         <listitem>
 167                 <para>
 168   Specifies a directory to contain transformed
 169   representations of the input files.
 170   By default, <option>-d</option> outputs a canonical representation
 171   (described below).
 172   You can select different output formats using <option>-c</option>
 173   and <option>-m</option>.
 174           </para>
 175           <para>
 176   The output filenames will
 177   be exactly the same as the input filenames or "STDIN" if the input is
 178   coming from standard input.  Therefore, you must be careful that the
 179   output file does not go into the same directory as the input
 180   file.  Otherwise, <command>&dhpackage;</command> will delete the
 181   input file before it generates the output file (just like running
 182   <literal>cat &lt; file &gt; file</literal> in most shells).
 183           </para>
 184           <para>
 185   Two structurally equivalent XML documents have a byte-for-byte
 186   identical canonical XML representation.
 187   Note that ignorable white space is considered significant and
 188   is treated equivalently to data.
 189   More on canonical XML can be found at
 190   http://www.jclark.com/xml/canonxml.html .
 191           </para>
 192         </listitem>
 193       </varlistentry>
 194
 195       <varlistentry>
 196         <term><option>-e encoding</option></term>
 197         <listitem>
 198                 <para>
 199    Specifies the character encoding for the document, overriding
 200    any document encoding declaration.  <command>&dhpackage;</command>
 201    supports four built-in encodings:
 202         <literal>US-ASCII</literal>,
 203         <literal>UTF-8</literal>,
 204         <literal>UTF-16</literal>, and
 205         <literal>ISO-8859-1</literal>.
 206    Also see the <option>-w</option> option.
 207            </para>
 208         </listitem>
 209       </varlistentry>
 210
 211       <varlistentry>
 212         <term><option>-m</option></term>
 213         <listitem>
 214                 <para>
 215   Outputs some strange sort of XML file that completely
 216   describes the the input file, including character postitions.
 217   Requires <option>-d</option> to specify an output file.
 218            </para>
 219         </listitem>
 220       </varlistentry>
 221
 222       <varlistentry>
 223         <term><option>-n</option></term>
 224         <listitem>
 225                 <para>
 226   Turns on namespace processing.  (describe namespaces)
 227   <option>-c</option> disables namespaces.
 228            </para>
 229         </listitem>
 230       </varlistentry>
 231
 232       <varlistentry>
 233         <term><option>-p</option></term>
 234         <listitem>
 235                 <para>
 236     Tells xmlwf to process external DTDs and parameter
 237     entities.
 238          </para>
 239          <para>
 240    Normally <command>&dhpackage;</command> never parses parameter
 241    entities.  <option>-p</option> tells it to always parse them.
 242    <option>-p</option> implies <option>-x</option>.
 243            </para>
 244         </listitem>
 245       </varlistentry>
 246
 247       <varlistentry>
 248         <term><option>-r</option></term>
 249         <listitem>
 250                 <para>
 251    Normally <command>&dhpackage;</command> memory-maps the XML file
 252    before parsing; this can result in faster parsing on many
 253    platforms.
 254    <option>-r</option> turns off memory-mapping and uses normal file
 255    IO calls instead.
 256    Of course, memory-mapping is automatically turned off
 257    when reading from standard input.
 258            </para>
 259                 <para>
 260    Use of memory-mapping can cause some platforms to report
 261    substantially higher memory usage for
 262    <command>&dhpackage;</command>, but this appears to be a matter of
 263    the operating system reporting memory in a strange way; there is
 264    not a leak in <command>&dhpackage;</command>.
 265            </para>
 266         </listitem>
 267       </varlistentry>
 268
 269       <varlistentry>
 270         <term><option>-s</option></term>
 271         <listitem>
 272                 <para>
 273   Prints an error if the document is not standalone.
 274   A document is standalone if it has no external subset and no
 275   references to parameter entities.
 276            </para>
 277         </listitem>
 278       </varlistentry>
 279
 280       <varlistentry>
 281         <term><option>-t</option></term>
 282         <listitem>
 283                 <para>
 284   Turns on timings.  This tells Expat to parse the entire file,
 285   but not perform any processing.
 286   This gives a fairly accurate idea of the raw speed of Expat itself
 287   without client overhead.
 288   <option>-t</option> turns off most of the output options
 289   (<option>-d</option>, <option>-m</option>, <option>-c</option>,
 290   ...).
 291            </para>
 292         </listitem>
 293       </varlistentry>
 294
 295       <varlistentry>
 296         <term><option>-v</option></term>
 297         <listitem>
 298                 <para>
 299   Prints the version of the Expat library being used, including some
 300   information on the compile-time configuration of the library, and
 301   then exits.
 302            </para>
 303         </listitem>
 304       </varlistentry>
 305
 306       <varlistentry>
 307         <term><option>-w</option></term>
 308         <listitem>
 309                 <para>
 310   Enables support for Windows code pages.
 311   Normally, <command>&dhpackage;</command> will throw an error if it
 312   runs across an encoding that it is not equipped to handle itself.  With
 313   <option>-w</option>, &dhpackage; will try to use a Windows code
 314   page.  See also <option>-e</option>.
 315            </para>
 316         </listitem>
 317       </varlistentry>
 318
 319       <varlistentry>
 320         <term><option>-x</option></term>
 321         <listitem>
 322                 <para>
 323   Turns on parsing external entities.
 324   </para>
 325 <para>
 326   Non-validating parsers are not required to resolve external
 327   entities, or even expand entities at all.
 328   Expat always expands internal entities (?),
 329   but external entity parsing must be enabled explicitly.
 330   </para>
 331   <para>
 332   External entities are simply entities that obtain their
 333   data from outside the XML file currently being parsed.
 334   </para>
 335   <para>
 336   This is an example of an internal entity:
 337 <literallayout>
 338 &lt;!ENTITY vers '1.0.2'&gt;
 339 </literallayout>
 340   </para>
 341   <para>
 342   And here are some examples of external entities:
 343
 344 <literallayout>
 345 &lt;!ENTITY header SYSTEM "header-&amp;vers;.xml"&gt;  (parsed)
 346 &lt;!ENTITY logo SYSTEM "logo.png" PNG&gt;         (unparsed)
 347 </literallayout>
 348
 349            </para>
 350         </listitem>
 351       </varlistentry>
 352
 353       <varlistentry>
 354         <term><option>--</option></term>
 355         <listitem>
 356                 <para>
 357     (Two hyphens.)
 358     Terminates the list of options.  This is only needed if a filename
 359     starts with a hyphen.  For example:
 360            </para>
 361 <literallayout>
 362 &dhpackage; -- -myfile.xml
 363 </literallayout>
 364                 <para>
 365     will run <command>&dhpackage;</command> on the file
 366     <filename>-myfile.xml</filename>.
 367            </para>
 368         </listitem>
 369       </varlistentry>
 370     </variablelist>
 371
 372         <para>
 373     Older versions of <command>&dhpackage;</command> do not support
 374     reading from standard input.
 375         </para>
 376   </refsect1>
 377
 378   <refsect1>
 379   <title>OUTPUT</title>
 380     <para>
 381         If an input file is not well-formed,
 382         <command>&dhpackage;</command> prints a single line describing
 383         the problem to standard output.  If a file is well formed,
 384         <command>&dhpackage;</command> outputs nothing.
 385         Note that the result code is <emphasis>not</emphasis> set.
 386         </para>
 387   </refsect1>
 388
 389   <refsect1>
 390     <title>BUGS</title>
 391         <para>
 392         According to the W3C standard, an XML file without a
 393         declaration at the beginning is not considered well-formed.
 394         However, <command>&dhpackage;</command> allows this to pass.
 395         </para>
 396         <para>
 397         <command>&dhpackage;</command> returns a 0 - noerr result,
 398         even if the file is not well-formed.  There is no good way for
 399         a program to use <command>&dhpackage;</command> to quickly
 400         check a file -- it must parse <command>&dhpackage;</command>'s
 401         standard output.
 402         </para>
 403         <para>
 404         The errors should go to standard error, not standard output.
 405         </para>
 406         <para>
 407         There should be a way to get <option>-d</option> to send its
 408         output to standard output rather than forcing the user to send
 409         it to a file.
 410         </para>
 411         <para>
 412         I have no idea why anyone would want to use the
 413         <option>-d</option>, <option>-c</option>, and
 414         <option>-m</option> options.  If someone could explain it to
 415         me, I'd like to add this information to this manpage.
 416         </para>
 417   </refsect1>
 418
 419   <refsect1>
 420     <title>ALTERNATIVES</title>
 421         <para>
 422           Here are some XML validators on the web:
 423
 424 <literallayout>
 425 http://www.hcrc.ed.ac.uk/~richard/xml-check.html
 426 http://www.stg.brown.edu/service/xmlvalid/
 427 http://www.scripting.com/frontier5/xml/code/xmlValidator.html
 428 http://www.xml.com/pub/a/tools/ruwf/check.html
 429 </literallayout>
 430
 431                  </para>
 432   </refsect1>
 433
 434   <refsect1>
 435     <title>SEE ALSO</title>
 436         <para>
 437
 438 <literallayout>
 439 The Expat home page:        http://www.libexpat.org/
 440 The W3 XML specification:   http://www.w3.org/TR/REC-xml
 441 </literallayout>
 442
 443         </para>
 444   </refsect1>
 445
 446   <refsect1>
 447     <title>AUTHOR</title>
 448     <para>
 449           This manual page was written by &dhusername; &dhemail; for
 450       the &debian; system (but may be used by others).  Permission is
 451       granted to copy, distribute and/or modify this document under
 452       the terms of the <acronym>GNU</acronym> Free Documentation
 453       License, Version 1.1.
 454         </para>
 455   </refsect1>
 456 </refentry>
 457
 458 <!-- Keep this comment at the end of the file
 459 Local variables:
 460 mode: sgml
 461 sgml-omittag:t
 462 sgml-shorttag:t
 463 sgml-minimize-attributes:nil
 464 sgml-always-quote-attributes:t
 465 sgml-indent-step:2
 466 sgml-indent-data:t
 467 sgml-parent-document:nil
 468 sgml-default-dtd-file:nil
 469 sgml-exposed-tags:nil
 470 sgml-local-catalogs:nil
 471 sgml-local-ecat-files:nil
 472 End:
 473 -->