summaryrefslogtreecommitdiff
path: root/Master/texmf-doc/doc/english/make-tex-work/html/ch10.html
blob: 9eea2211c0bda751fcd10dbf9658c64ba5dcdb7a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <meta name="generator"
    content="HTML Tidy for Linux/x86 (vers 1st March 2002), see www.w3.org" />
    <meta http-equiv="Content-Type"
    content="text/html; charset=ISO-8859-1" />

    <title>Chapter&#160;10.&#160;Online Documentation</title>
    <link rel="stylesheet" href="mtw.css" type="text/css" />
    <meta name="generator"
    content="DocBook XSL Stylesheets V1.53.0" />
    <link rel="home" href="index.html" title="Making TeX Work" />
    <link rel="up" href="pt02.html"
    title="Part&#160;II.&#160;Elements of a Complex Document" />
    <link rel="previous" href="ch09.html"
    title="Chapter&#160;9.&#160;Previewing" />
    <link rel="next" href="ch11.html"
    title="Chapter&#160;11.&#160;Introducing MetaFont" />
  </head>

  <body>
    <div class="navheader">
      <table border="0" cellpadding="0" cellspacing="0"
      width="100%" summary="Navigation table">
        <tr>
          <td align="left">&#160;<a title="Making TeX Work"
          href="index.html"><img src="figures/nav-home.png"
          alt="Home" border="0" /></a>&#160;<a
          title="Chapter&#160;9.&#160;Previewing"
          href="ch09.html"><img src="figures/nav-prev.png"
          alt="Prev" border="0" /></a>&#160;<a
          title="Part&#160;II.&#160;Elements of a Complex Document"
          href="pt02.html"><img src="figures/nav-up.png" alt="Up"
          border="0" /></a>&#160;<a
          title="Chapter&#160;11.&#160;Introducing MetaFont"
          href="ch11.html"><img src="figures/nav-next.png"
          alt="Next" border="0" /></a></td>

          <td align="right"><i>Making TeX Work</i> Version 1.0.1
          <span class="alpha-version">(<a
          href="co01.html"><em>Alpha</em></a>)</span></td>
        </tr>
      </table>
    </div>

    <div class="chapter">
      <div class="titlepage">
        <div>
          <h2 class="title"><a id="chap.online"
          name="chap.online"></a>Chapter&#160;10.&#160;Online
          Documentation</h2>
        </div>

        <div>
          <p class="releaseinfo">$Revision: 1.1 $</p>
        </div>

        <div>
          <p class="pubdate">$Date: 2002/08/23 14:31:13 $</p>
        </div>
        <hr class="component-separator" />
      </div>

      <p>Some common kinds of documentation---for example, manuals
      for computer programs---present a unique challenge to the
      author. In many cases, it would be nice to be able to provide
      online documentation<a id="id2910943" class="indexterm"
      name="id2910943"></a><a id="id2910951" class="indexterm"
      name="id2910951"></a> in addition to a typeset manual.</p>

      <p>One option is to maintain two different documents: one for
      publication and one for online access. This is difficult to
      maintain and is prone to error. As the documentation evolves,
      it is almost inevitable that some changes to one document
      will not be implemented in the other.</p>

      <p>Another option is to include only very limited formatting
      information in the document designed for publication so that
      it is easy to &#8220;strip out&#8221; the formatting commands
      and produce an online manual. The unfortunate side effect of
      this approach is that the resulting typeset documentation
      doesn't have a very professional appearance.</p>

      <p>With care, TeX can be the basis for a middle-ground
      approach to this problem.<sup>[<a id="id2910836"
      name="id2910836" href="#ftn.id2910836">109</a>]</sup> If you
      are starting a new documentation project, TeXinfo<a
      id="id2910846" class="indexterm" name="id2910846"></a> and
      LameTeX<a id="id2910856" class="indexterm"
      name="id2910856"></a> provide two alternatives for the
      production of typeset and online documentation from the same
      source. \LaTeX2HTML<a id="id2910870" class="indexterm"
      name="id2910870"></a> and \LaTeX2hy<a id="id2910881"
      class="indexterm" name="id2910881"></a> provide alternatives
      that may be suitable for existing documentation.</p>

      <p>You'll find that the best results occur when you plan
      ahead: if you know that you need both typeset and ASCII
      documentation, try to use tools that will make the task
      easier. But, even if you try to plan ahead, it's not uncommon
      to find out after the fact that you need or want ASCII
      documentation. If you don't have the TeX sources, you'll just
      have to take the best results you can get with one of the
      tools described later in this chapter and do whatever
      hand-editing is required.</p>

      <p>If you have the TeX sources for a document, here are some
      guidelines that can help improve the quality of the
      conversion to plain ASCII:</p>

      <div class="itemizedlist">
        <ul type="disc">
          <li>
            <p>Redefine all font commands to use \tt. This makes
            TeX work with a fixed-width font. You will probably get
            many, many overfull and underfull box messages. This
            can't be helped. Setting \tolerance and \hbadness to
            large values (10000 with TeX 2.x or 100000 with TeX
            3.x, for example) will reduce the number of
            warnings.</p>

            <p>Similarly, redefine all the commands that change
            font size to select the same size (probably 10pt or
            12pt will work best, but larger values may be better if
            you have wide margins).</p>
          </li>

          <li>
            <p>Don't use any special fonts---no <tt>picture</tt>
            environments in LaTeX, for example. Take out rules,
            too.</p>
          </li>

          <li>
            <p>Use \raggedright. There's no point in trying to line
            up the right margin.</p>
          </li>

          <li>
            <p>Remove or redefine all mathematics to avoid the use
            of math-mode. It won't work; don't ask TeX to try.</p>
          </li>

          <li>
            <p>Remove all tables (\halign in Plain TeX,
            <tt>tabular</tt> environments in LaTeX).</p>
          </li>

          <li>
            <p>Remove floating environments; this may help.</p>
          </li>

          <li>
            <p>Depending on your level of expertise and the number
            of documents that you have to convert, redefine
            footnotes and other environments to give you more
            marginal improvements.</p>
          </li>
        </ul>
      </div>

      <p>The <tt>ascii.sty</tt> style<a id="id2916135"
      class="indexterm" name="id2916135"></a> for LaTeX
      encapsulates many of these rules for you.</p>

      <div class="section">
        <div class="titlepage">
          <div>
            <h2 class="title" style="clear: both"><a id="id2916146"
            name="id2916146"></a>Something Is Lost</h2>
          </div>
        </div>

        <p>Many things that can easily be represented on paper
        cannot be represented in plain ASCII. One reason for this
        is that plain ASCII output is not proportionally spaced.
        Also, in ASCII you can move up or down only by rows, and
        left or right only by columns; you can't move down &#8220;3
        points&#8221; on a terminal to typeset a subscript, for
        example.</p>

        <p>These differences combine to make many things
        impossible. For all of its marvelous sophistication, TeX
        cannot help you typeset mathematics<a id="id2916172"
        class="indexterm" name="id2916172"></a> in plain ASCII. It
        just can't be done. Most tables can't be done in plain
        ASCII either (at least not if you want lines that are only
        80 characters or so long).</p>

        <p>The following sections describe tools that may help you
        achieve the goal of online and typeset documentation from
        the same sources. Each tool has its own advantages and
        disadvantages. The ones that work best for you will depend
        on the type of documentation you are producing and the
        amount of work you are willing to do.</p>
      </div>

      <div class="section">
        <div class="titlepage">
          <div>
            <h2 class="title" style="clear: both"><a id="id2916199"
            name="id2916199"></a>TeXinfo</h2>
          </div>
        </div>

        <p>TeXinfo<a id="id2916208" class="indexterm"
        name="id2916208"></a> is the document formatting system
        adopted by the Free Software Foundation (FSF)<a
        id="id2916220" class="indexterm" name="id2916220"></a> and
        the GNU Project<a id="id2916230" class="indexterm"
        name="id2916230"></a>. It is a special TeX format that is
        very different from standard TeX.<sup>[<a id="id2916239"
        name="id2916239" href="#ftn.id2916239">110</a>]</sup> The
        goal of TeXinfo is to devise an input format that can be
        processed by TeX to produce typeset output and then be
        processed by another program to produce <span
        class="emphasis"><em>hypertext</em></span> output. (The
        other program in this case is <b>MakeInfo</b><a
        id="id2916259" class="indexterm"
        name="id2916259"></a>.)</p>

        <p>TeXinfo supports ordinary text, sectioning commands,
        itemize and enumeration environments, footnotes,
        cross-references, tables of contents, lists of figures and
        tables, and multiple indexes.</p>

        <p>The TeXinfo example from Chapter&#160;<a
        href="ch04.html"
        title="Chapter&#160;4.&#160;Macro Packages">Chapter&#160;4</a>,
        <span class="emphasis"><em><a href="ch04.html"
        title="Chapter&#160;4.&#160;Macro Packages">Chapter&#160;4</a></em></span>,
        is reproduced in Example&#160;<a
        href="ch10.html#ex.on.infinp"
        title="Example&#160;10.1.&#160;TeXinfo Commands">Example&#160;10.1</a>
        (the TeXinfo input), Figure&#160;<a
        href="ch10.html#fig.on.infex"
        title="Figure&#160;10.1.&#160;TeXinfo sample page">Figure&#160;10.1</a>
        (the typeset page), and Figure&#160;<a
        href="ch10.html#fig.on.infinf"
        title="Figure&#160;10.2.&#160;Online documentation produced by MakeInfo">
        Figure&#160;10.2</a> (the resulting online
        documentation).</p>

        <div class="example">
          <a id="ex.on.infinp" name="ex.on.infinp"></a>

          <p class="title"><b>Example&#160;10.1.&#160;TeXinfo
          Commands</b></p>
<pre class="programlisting">
<a type="simple" show="embed" actuate="onLoad" href="perf-inf"></a>
</pre>
        </div>

        <div class="figure">
          <a id="fig.on.infex" name="fig.on.infex"></a>

          <p class="title"><b>Figure&#160;10.1.&#160;TeXinfo sample
          page</b></p>

          <div class="mediaobject">
            <img src="perf-inf.eps" />
          </div>
        </div>

        <div class="figure">
          <a id="fig.on.infinf" name="fig.on.infinf"></a>

          <p class="title"><b>Figure&#160;10.2.&#160;Online
          documentation produced by MakeInfo</b></p>

          <div class="literallayout">
            <p>&#160;&#160;<br />
            &#160;&#160;&#160;&#160;\FramedVerbInput{perf-inf.inf}<br />

            </p>
          </div>
        </div>

        <p>The output from <b>MakeInfo</b> is very nearly pure
        ASCII. The motivation for {hypertext} output is to make
        cross references dynamic<a id="id2916438" class="indexterm"
        name="id2916438"></a> when the &#8220;info&#8221; version
        of the document is used for online reference.<sup>[<a
        id="id2916455" name="id2916455"
        href="#ftn.id2916455">111</a>]</sup> The result is close
        enough to pure ASCII that converting it to pure ASCII is
        not (usually) too difficult. For example, the <span
        class="emphasis"><em>comp.fonts</em></span> newsgroup<a
        id="id2916474" class="indexterm" name="id2916474"></a>'s
        Frequently Asked Questions list is maintained as a TeXinfo
        document. It is posted as an info version that has been
        processed by a Perl script to &#8220;flatten&#8221; the
        hypertext.</p>

        <p>The TeXinfo format is well documented, so a brief
        description here will suffice. First, the backslash, which
        is ordinarily used to introduce control sequences in TeX,
        is not special. Instead the &#8220;@&#8221;-sign is used.
        Second, a TeXinfo document is divided into &#8220;nodes<a
        id="id2916507" class="indexterm"
        name="id2916507"></a>.&#8221; A node corresponds roughly to
        a chapter or a large section of a chapter. In the online
        documentation, it is easy to jump between related
        nodes.</p>

        <p>Because the info version of the document is ASCII text,
        many of the special typesetting features of TeX aren't
        applicable. To support them in the typeset document,
        TeXinfo allows you to specify that some portions of the
        input should be seen only by TeX and some should be seen
        only by <b>MakeInfo</b>. Example&#160;<a
        href="ch10.html#ex.on.infinp"
        title="Example&#160;10.1.&#160;TeXinfo Commands">Example&#160;10.1</a>
        uses this feature to typeset mathematics using the best
        features of both TeX and <b>MakeInfo</b>.</p>
      </div>

      <div class="section">
        <div class="titlepage">
          <div>
            <h2 class="title" style="clear: both"><a id="id2916555"
            name="id2916555"></a>\LaTeX2HTML</h2>
          </div>
        </div>

        <p>\LaTeX2HTML<a id="id2916564" class="indexterm"
        name="id2916564"></a> attempts to convert LaTeX documents
        into HTML<a id="id2916576" class="indexterm"
        name="id2916576"></a>, the document structuring language
        used by the World Wide Web (WWW)<a id="id2916586"
        class="indexterm" name="id2916586"></a> project. HTML
        stands for HyperText Markup Language<a id="id2916595"
        class="indexterm" name="id2916595"></a>; it is a way of
        describing documents in terms of their structure (headings,
        paragraphs, lists, etc.). SGML<a id="id2916606"
        class="indexterm" name="id2916606"></a>, the Standard
        Generalized Markup Language, provides a framework for
        developing structured documentation; HTML is one specific
        SGML document type. HTML documents are displayed by special
        programs called browsers<a id="id2916618" class="indexterm"
        name="id2916618"></a> that interpret the markup and present
        the information in a consistent manner. Because an HTML
        document is described in terms of its structure and not its
        appearance, HTML documents can be effectively displayed by
        browsers in non-graphical environments.</p>

        <p>One of the most important features of HTML documents is
        the ability to form hypertext links<a id="id2916638"
        class="indexterm" name="id2916638"></a><a id="id2916647"
        class="indexterm" name="id2916647"></a> between documents.
        Hypertext links allow you to build dynamic relationships
        between documents. For example, selecting a marked word or
        phrase in the current document displays more information
        about the topic, or a list of related topics.</p>

        <p>\LaTeX2HTML preserves many of the features of a LaTeX
        document in HTML. Elements that are too complex to
        represent in HTML, such as mathematical equations and logos
        like &#8220;TeX,&#8221; are converted into graphic images
        that can be displayed online by graphical browsers. All
        types of cross referencing elements (including footnotes)
        are preserved as hypertext links.</p>

        <p>When installed, \LaTeX2HTML understands many basic LaTeX
        commands, but it can be customized to handle other styles.
        \LaTeX2HTML is written in <b>Perl</b>.</p>

        <p>All in all, \LaTeX2HTML is one of the easiest and most
        effective tools for translating typeset documentation into
        a format suitable for online presentation. In a graphical
        environment like X11, Microsoft Windows, or the Macintosh,
        HTML documents offer very good support for online
        documentation.</p>
      </div>

      <div class="section">
        <div class="titlepage">
          <div>
            <h2 class="title" style="clear: both"><a id="id2916701"
            name="id2916701"></a>LameTeX</h2>
          </div>
        </div>

        <p>LameTeX<a id="id2916710" class="indexterm"
        name="id2916710"></a> is a PostScript translator<a
        id="id2916722" class="indexterm" name="id2916722"></a> for
        a (very limited) subset of LaTeX. One of its original
        design goals, the inclusion of sophisticated PostScript
        commands directly in a LaTeX document, has been superseded
        by the PSTricks<a id="id2916733" class="indexterm"
        name="id2916733"></a> package. However, one of the side
        effects of a special-purpose translator for LaTeX is the
        ability of that translator to produce different kinds of
        output, including plain ASCII.</p>

        <p>The primary advantage of this method is that it does not
        require learning an entirely foreign macro package like
        TeXinfo. The disadvantage is that it understands only a
        very small subset of LaTeX. This subset includes <span
        class="emphasis"><em>only</em></span> the following
        commands:</p>

        <div class="informaltable">
          <table border="1">
            <colgroup>
              <col align="left" />
              <col align="left" />
              <col align="left" />
            </colgroup>

            <tbody>
              <tr>
                <td align="left">\#</td>

                <td align="left">\footnotesize</td>

                <td align="left">\ref</td>
              </tr>

              <tr>
                <td align="left">\$</td>

                <td align="left">\hspace</td>

                <td align="left">\rm</td>
              </tr>

              <tr>
                <td align="left">\%</td>

                <td align="left">\hspace*</td>

                <td align="left">\sc</td>
              </tr>

              <tr>
                <td align="left">\&#160;</td>

                <td align="left">\huge</td>

                <td align="left">\scriptsize</td>
              </tr>

              <tr>
                <td align="left">\Huge</td>

                <td align="left">\include</td>

                <td align="left">\section</td>
              </tr>

              <tr>
                <td align="left">\LARGE</td>

                <td align="left">\input</td>

                <td align="left">\section*</td>
              </tr>

              <tr>
                <td align="left">\Large</td>

                <td align="left">\it</td>

                <td align="left">\setlength</td>
              </tr>

              <tr>
                <td align="left">\_</td>

                <td align="left">\item</td>

                <td align="left">\sf</td>
              </tr>

              <tr>
                <td align="left">\addtolength</td>

                <td align="left">\itemize</td>

                <td align="left">\sl</td>
              </tr>

              <tr>
                <td align="left">\backslash</td>

                <td align="left">\label</td>

                <td align="left">\small\smallskip</td>
              </tr>

              <tr>
                <td align="left">\begin</td>

                <td align="left">\large</td>

                <td align="left">\subparagraph</td>
              </tr>

              <tr>
                <td align="left">\bf</td>

                <td align="left">\ldots</td>

                <td align="left">\subparagraph*</td>
              </tr>

              <tr>
                <td align="left">\bigskip</td>

                <td align="left">\medskip</td>

                <td align="left">\subsection</td>
              </tr>

              <tr>
                <td align="left">\center</td>

                <td align="left">\newlength</td>

                <td align="left">\subsection*</td>
              </tr>

              <tr>
                <td align="left">\chapter</td>

                <td align="left">\newline</td>

                <td align="left">\subsubsection</td>
              </tr>

              <tr>
                <td align="left">\chapter*</td>

                <td align="left">\normalsize</td>

                <td align="left">\subsubsection*</td>
              </tr>

              <tr>
                <td align="left">\clearpage</td>

                <td align="left">\par</td>

                <td align="left">\tiny</td>
              </tr>

              <tr>
                <td align="left">\description</td>

                <td align="left">\paragraph</td>

                <td align="left">\today</td>
              </tr>

              <tr>
                <td align="left">\document</td>

                <td align="left">\paragraph*</td>

                <td align="left">\tt</td>
              </tr>

              <tr>
                <td align="left">\documentstyle</td>

                <td align="left">\part</td>

                <td align="left">\verbatim</td>
              </tr>

              <tr>
                <td align="left">\em</td>

                <td align="left">\part*</td>

                <td align="left">\verbatim*</td>
              </tr>

              <tr>
                <td align="left">\end</td>

                <td align="left">\quotation</td>

                <td align="left">\verse</td>
              </tr>

              <tr>
                <td align="left">\enumerate</td>

                <td align="left">\quote</td>

                <td align="left">\vspace</td>
              </tr>

              <tr>
                <td align="left">\flushleft</td>

                <td align="left">\raggedleft</td>

                <td align="left">\vspace*</td>
              </tr>

              <tr>
                <td align="left">\flushright</td>

                <td align="left">\raggedright</td>

                <td class="auto-generated">&#160;</td>
              </tr>
            </tbody>
          </table>
        </div>

        <p>In addition, unlike LaTeX, LameTeX doesn't understand
        any Plain TeX commands (other than the ones listed).</p>
      </div>

      <div class="section">
        <div class="titlepage">
          <div>
            <h2 class="title" style="clear: both"><a id="id2917217"
            name="id2917217"></a>latex2hy</h2>
          </div>
        </div>

        <p><b>latex2hy</b><a id="id2917230" class="indexterm"
        name="id2917230"></a> is a LaTeX-to-ASCII converter<a
        id="id2917238" class="indexterm" name="id2917238"></a>. It
        has several options for controlling the input and output
        character sets. In addition, <b>latex2hy</b> has a number
        of options for improving the quality of both ASCII and
        printed documentation. For example, input documents can
        contain both TeX and ASCII representations for complex
        objects (like mathematical formulae). The printed
        documentation uses the TeX version while <b>latex2hy</b>
        uses the ASCII version. Provision is also made for
        &#8220;fixups,&#8221; which allow character sequences from
        the input text to be translated into different sequences on
        output. For example, &#8220;$9.81\frac{m}{s^2}$&#8221; can
        be automatically translated into <tt>9.81m/s^2</tt>. By
        adding specific fixups to each document that you translate,
        you can obtain successively better approximations
        automatically.</p>

        <p><b>latex2hy</b> gives particular attention to cross
        references<a id="id2917305" class="indexterm"
        name="id2917305"></a>. Cross references are translated into
        &#8220;links<a id="id2917320" class="indexterm"
        name="id2917320"></a>&#8221; between topics in <span
        class="emphasis"><em>hypertext</em></span> output formats.
        Currently, only the <span
        class="emphasis"><em>TurboVision</em></span><a
        id="id2917336" class="indexterm" name="id2917336"></a>
        hypertext format is supported, although several other
        formats are being considered.</p>
      </div>

      <div class="section">
        <div class="titlepage">
          <div>
            <h2 class="title" style="clear: both"><a id="id2917348"
            name="id2917348"></a>detex</h2>
          </div>
        </div>

        <p><b>detex</b><a id="id2917361" class="indexterm"
        name="id2917361"></a> is a simple program that does little
        more than strip control sequences and other TeXish
        character sequences from your document. Doing this makes
        the document more amenable to other kinds of processing
        (like spellchecking) but does a poor job of producing
        &#8220;online documentation.&#8221; Still, it's an
        option.</p>
      </div>

      <div class="section">
        <div class="titlepage">
          <div>
            <h2 class="title" style="clear: both"><a id="id2917381"
            name="id2917381"></a>dvispell</h2>
          </div>
        </div>

        <p>The <b>dvispell</b><a id="id2917395" class="indexterm"
        name="id2917395"></a> program produces plain text output
        from a <tt>DVI</tt> file. It is not a spellchecker, but it
        was designed to extract the words from a TeX document which
        were then fed to a spellchecking program that was unable to
        ignore TeX control sequences.</p>

        <p>The <b>dvispell</b> program is part of the emTeX<a
        id="id2917428" class="indexterm" name="id2917428"></a>
        package, and it is remarkably sophisticated. There are many
        ways in which <b>dvispell</b> can be programmed to perform
        complex manipulations. One special strength of
        <b>dvispell</b> is its ability to handle conversion of
        accented characters and Greek symbols.</p>

        <p><b>dvispell</b> differs from the other programs
        described here because it works with TeX output, the
        <tt>DVI</tt> file. On the one hand, this provides
        <b>dvispell</b> with more information (character positions,
        line breaks, floating bodies, etc). On the other hand, all
        of the formatting commands are missing, so it isn't easy to
        determine what the user had in mind. (It's a bit like
        reverse-engineering a piece of software---without the
        source code, it's not always easy to tell why things look
        the way they do.) But <b>dvispell</b> gives you access to
        most of the information that is present in the <tt>DVI</tt>
        file.</p>
      </div>

      <div class="footnotes">
        <br />
        <hr width="100" align="left" />

        <div class="footnote">
          <p><sup>[<a id="ftn.id2910836" name="ftn.id2910836"
          href="#id2910836">109</a>]</sup> {Structured markup
          languages like SGML also address this problem, but they
          introduce their own set of difficulties. Regardless of
          whatever advantages they may hold, I'm not going to
          discuss them here.}</p>
        </div>

        <div class="footnote">
          <p><sup>[<a id="ftn.id2916239" name="ftn.id2916239"
          href="#id2916239">110</a>]</sup> {A LaTeX implementation,
          called LaTeXinfo, is also available.}</p>
        </div>

        <div class="footnote">
          <p><sup>[<a id="ftn.id2916455" name="ftn.id2916455"
          href="#id2916455">111</a>]</sup> {&#8220;Info&#8221; is
          the name of both the output format and a program for
          displaying the text in a hypertext fashion. Another
          common way to access info files is with the GNU emacs
          online help system.}</p>
        </div>
      </div>
    </div>

    <div class="navfooter">
      <table width="100%" summary="Navigation table">
        <tr>
          <td width="40%" align="left"><a
          title="Chapter&#160;9.&#160;Previewing"
          href="ch09.html"><img src="figures/nav-prev.png"
          alt="Prev" border="0" /></a>&#160;</td>

          <td width="20%" align="center"><a title="Making TeX Work"
          href="index.html"><img src="figures/nav-home.png"
          alt="Home" border="0" /></a></td>

          <td width="40%" align="right">&#160;<a
          title="Chapter&#160;11.&#160;Introducing MetaFont"
          href="ch11.html"><img src="figures/nav-next.png"
          alt="Next" border="0" /></a></td>
        </tr>

        <tr>
          <td width="40%" align="left">
          Chapter&#160;9.&#160;Previewing&#160;</td>

          <td width="20%" align="center"><a
          title="Part&#160;II.&#160;Elements of a Complex Document"
          href="pt02.html"><img src="figures/nav-up.png" alt="Up"
          border="0" /></a></td>

          <td width="40%" align="right">
          &#160;Chapter&#160;11.&#160;Introducing MetaFont</td>
        </tr>
      </table>
    </div>
  </body>
</html>