lib/perl5/5.8.8/Pod/PlainText.pm

   1 # Pod::PlainText -- Convert POD data to formatted ASCII text.
   2 # $Id: Text.pm,v 2.1 1999/09/20 11:53:33 eagle Exp $
   3 #
   4 # Copyright 1999-2000 by Russ Allbery <rra@stanford.edu>
   5 #
   6 # This program is free software; you can redistribute it and/or modify it
   7 # under the same terms as Perl itself.
   8 #
   9 # This module is intended to be a replacement for Pod::Text, and attempts to
  10 # match its output except for some specific circumstances where other
  11 # decisions seemed to produce better output.  It uses Pod::Parser and is
  12 # designed to be very easy to subclass.
  13
  14 ############################################################################
  15 # Modules and declarations
  16 ############################################################################
  17
  18 package Pod::PlainText;
  19
  20 require 5.005;
  21
  22 use Carp qw(carp croak);
  23 use Pod::Select ();
  24
  25 use strict;
  26 use vars qw(@ISA %ESCAPES $VERSION);
  27
  28 # We inherit from Pod::Select instead of Pod::Parser so that we can be used
  29 # by Pod::Usage.
  30 @ISA = qw(Pod::Select);
  31
  32 $VERSION = '2.02';
  33
  34
  35 ############################################################################
  36 # Table of supported E<> escapes
  37 ############################################################################
  38
  39 # This table is taken near verbatim from Pod::PlainText in Pod::Parser,
  40 # which got it near verbatim from the original Pod::Text.  It is therefore
  41 # credited to Tom Christiansen, and I'm glad I didn't have to write it.  :)
  42 %ESCAPES = (
  43     'amp'       =>    '&',      # ampersand
  44     'lt'        =>    '<',      # left chevron, less-than
  45     'gt'        =>    '>',      # right chevron, greater-than
  46     'quot'      =>    '"',      # double quote
  47
  48     "Aacute"    =>    "\xC1",   # capital A, acute accent
  49     "aacute"    =>    "\xE1",   # small a, acute accent
  50     "Acirc"     =>    "\xC2",   # capital A, circumflex accent
  51     "acirc"     =>    "\xE2",   # small a, circumflex accent
  52     "AElig"     =>    "\xC6",   # capital AE diphthong (ligature)
  53     "aelig"     =>    "\xE6",   # small ae diphthong (ligature)
  54     "Agrave"    =>    "\xC0",   # capital A, grave accent
  55     "agrave"    =>    "\xE0",   # small a, grave accent
  56     "Aring"     =>    "\xC5",   # capital A, ring
  57     "aring"     =>    "\xE5",   # small a, ring
  58     "Atilde"    =>    "\xC3",   # capital A, tilde
  59     "atilde"    =>    "\xE3",   # small a, tilde
  60     "Auml"      =>    "\xC4",   # capital A, dieresis or umlaut mark
  61     "auml"      =>    "\xE4",   # small a, dieresis or umlaut mark
  62     "Ccedil"    =>    "\xC7",   # capital C, cedilla
  63     "ccedil"    =>    "\xE7",   # small c, cedilla
  64     "Eacute"    =>    "\xC9",   # capital E, acute accent
  65     "eacute"    =>    "\xE9",   # small e, acute accent
  66     "Ecirc"     =>    "\xCA",   # capital E, circumflex accent
  67     "ecirc"     =>    "\xEA",   # small e, circumflex accent
  68     "Egrave"    =>    "\xC8",   # capital E, grave accent
  69     "egrave"    =>    "\xE8",   # small e, grave accent
  70     "ETH"       =>    "\xD0",   # capital Eth, Icelandic
  71     "eth"       =>    "\xF0",   # small eth, Icelandic
  72     "Euml"      =>    "\xCB",   # capital E, dieresis or umlaut mark
  73     "euml"      =>    "\xEB",   # small e, dieresis or umlaut mark
  74     "Iacute"    =>    "\xCD",   # capital I, acute accent
  75     "iacute"    =>    "\xED",   # small i, acute accent
  76     "Icirc"     =>    "\xCE",   # capital I, circumflex accent
  77     "icirc"     =>    "\xEE",   # small i, circumflex accent
  78     "Igrave"    =>    "\xCD",   # capital I, grave accent
  79     "igrave"    =>    "\xED",   # small i, grave accent
  80     "Iuml"      =>    "\xCF",   # capital I, dieresis or umlaut mark
  81     "iuml"      =>    "\xEF",   # small i, dieresis or umlaut mark
  82     "Ntilde"    =>    "\xD1",   # capital N, tilde
  83     "ntilde"    =>    "\xF1",   # small n, tilde
  84     "Oacute"    =>    "\xD3",   # capital O, acute accent
  85     "oacute"    =>    "\xF3",   # small o, acute accent
  86     "Ocirc"     =>    "\xD4",   # capital O, circumflex accent
  87     "ocirc"     =>    "\xF4",   # small o, circumflex accent
  88     "Ograve"    =>    "\xD2",   # capital O, grave accent
  89     "ograve"    =>    "\xF2",   # small o, grave accent
  90     "Oslash"    =>    "\xD8",   # capital O, slash
  91     "oslash"    =>    "\xF8",   # small o, slash
  92     "Otilde"    =>    "\xD5",   # capital O, tilde
  93     "otilde"    =>    "\xF5",   # small o, tilde
  94     "Ouml"      =>    "\xD6",   # capital O, dieresis or umlaut mark
  95     "ouml"      =>    "\xF6",   # small o, dieresis or umlaut mark
  96     "szlig"     =>    "\xDF",   # small sharp s, German (sz ligature)
  97     "THORN"     =>    "\xDE",   # capital THORN, Icelandic
  98     "thorn"     =>    "\xFE",   # small thorn, Icelandic
  99     "Uacute"    =>    "\xDA",   # capital U, acute accent
 100     "uacute"    =>    "\xFA",   # small u, acute accent
 101     "Ucirc"     =>    "\xDB",   # capital U, circumflex accent
 102     "ucirc"     =>    "\xFB",   # small u, circumflex accent
 103     "Ugrave"    =>    "\xD9",   # capital U, grave accent
 104     "ugrave"    =>    "\xF9",   # small u, grave accent
 105     "Uuml"      =>    "\xDC",   # capital U, dieresis or umlaut mark
 106     "uuml"      =>    "\xFC",   # small u, dieresis or umlaut mark
 107     "Yacute"    =>    "\xDD",   # capital Y, acute accent
 108     "yacute"    =>    "\xFD",   # small y, acute accent
 109     "yuml"      =>    "\xFF",   # small y, dieresis or umlaut mark
 110
 111     "lchevron"  =>    "\xAB",   # left chevron (double less than)
 112     "rchevron"  =>    "\xBB",   # right chevron (double greater than)
 113 );
 114
 115
 116 ############################################################################
 117 # Initialization
 118 ############################################################################
 119
 120 # Initialize the object.  Must be sure to call our parent initializer.
 121 sub initialize {
 122     my $self = shift;
 123
 124     $$self{alt}      = 0  unless defined $$self{alt};
 125     $$self{indent}   = 4  unless defined $$self{indent};
 126     $$self{loose}    = 0  unless defined $$self{loose};
 127     $$self{sentence} = 0  unless defined $$self{sentence};
 128     $$self{width}    = 76 unless defined $$self{width};
 129
 130     $$self{INDENTS}  = [];              # Stack of indentations.
 131     $$self{MARGIN}   = $$self{indent};  # Current left margin in spaces.
 132
 133     $self->SUPER::initialize;
 134 }
 135
 136
 137 ############################################################################
 138 # Core overrides
 139 ############################################################################
 140
 141 # Called for each command paragraph.  Gets the command, the associated
 142 # paragraph, the line number, and a Pod::Paragraph object.  Just dispatches
 143 # the command to a method named the same as the command.  =cut is handled
 144 # internally by Pod::Parser.
 145 sub command {
 146     my $self = shift;
 147     my $command = shift;
 148     return if $command eq 'pod';
 149     return if ($$self{EXCLUDE} && $command ne 'end');
 150     $self->item ("\n") if defined $$self{ITEM};
 151     $command = 'cmd_' . $command;
 152     $self->$command (@_);
 153 }
 154
 155 # Called for a verbatim paragraph.  Gets the paragraph, the line number, and
 156 # a Pod::Paragraph object.  Just output it verbatim, but with tabs converted
 157 # to spaces.
 158 sub verbatim {
 159     my $self = shift;
 160     return if $$self{EXCLUDE};
 161     $self->item if defined $$self{ITEM};
 162     local $_ = shift;
 163     return if /^\s*$/;
 164     s/^(\s*\S+)/(' ' x $$self{MARGIN}) . $1/gme;
 165     $self->output ($_);
 166 }
 167
 168 # Called for a regular text block.  Gets the paragraph, the line number, and
 169 # a Pod::Paragraph object.  Perform interpolation and output the results.
 170 sub textblock {
 171     my $self = shift;
 172     return if $$self{EXCLUDE};
 173     $self->output ($_[0]), return if $$self{VERBATIM};
 174     local $_ = shift;
 175     my $line = shift;
 176
 177     # Perform a little magic to collapse multiple L<> references.  This is
 178     # here mostly for backwards-compatibility.  We'll just rewrite the whole
 179     # thing into actual text at this part, bypassing the whole internal
 180     # sequence parsing thing.
 181     s{
 182         (
 183           L<                    # A link of the form L</something>.
 184               /
 185               (
 186                   [:\w]+        # The item has to be a simple word...
 187                   (\(\))?       # ...or simple function.
 188               )
 189           >
 190           (
 191               ,?\s+(and\s+)?    # Allow lots of them, conjuncted.
 192               L<
 193                   /
 194                   (
 195                       [:\w]+
 196                       (\(\))?
 197                   )
 198               >
 199           )+
 200         )
 201     } {
 202         local $_ = $1;
 203         s%L</([^>]+)>%$1%g;
 204         my @items = split /(?:,?\s+(?:and\s+)?)/;
 205         my $string = "the ";
 206         my $i;
 207         for ($i = 0; $i < @items; $i++) {
 208             $string .= $items[$i];
 209             $string .= ", " if @items > 2 && $i != $#items;
 210             $string .= " and " if ($i == $#items - 1);
 211         }
 212         $string .= " entries elsewhere in this document";
 213         $string;
 214     }gex;
 215
 216     # Now actually interpolate and output the paragraph.
 217     $_ = $self->interpolate ($_, $line);
 218     s/\s+$/\n/;
 219     if (defined $$self{ITEM}) {
 220         $self->item ($_ . "\n");
 221     } else {
 222         $self->output ($self->reformat ($_ . "\n"));
 223     }
 224 }
 225
 226 # Called for an interior sequence.  Gets the command, argument, and a
 227 # Pod::InteriorSequence object and is expected to return the resulting text.
 228 # Calls code, bold, italic, file, and link to handle those types of
 229 # sequences, and handles S<>, E<>, X<>, and Z<> directly.
 230 sub interior_sequence {
 231     my $self = shift;
 232     my $command = shift;
 233     local $_ = shift;
 234     return '' if ($command eq 'X' || $command eq 'Z');
 235
 236     # Expand escapes into the actual character now, carping if invalid.
 237     if ($command eq 'E') {
 238         return $ESCAPES{$_} if defined $ESCAPES{$_};
 239         carp "Unknown escape: E<$_>";
 240         return "E<$_>";
 241     }
 242
 243     # For all the other sequences, empty content produces no output.
 244     return if $_ eq '';
 245
 246     # For S<>, compress all internal whitespace and then map spaces to \01.
 247     # When we output the text, we'll map this back.
 248     if ($command eq 'S') {
 249         s/\s{2,}/ /g;
 250         tr/ /\01/;
 251         return $_;
 252     }
 253
 254     # Anything else needs to get dispatched to another method.
 255     if    ($command eq 'B') { return $self->seq_b ($_) }
 256     elsif ($command eq 'C') { return $self->seq_c ($_) }
 257     elsif ($command eq 'F') { return $self->seq_f ($_) }
 258     elsif ($command eq 'I') { return $self->seq_i ($_) }
 259     elsif ($command eq 'L') { return $self->seq_l ($_) }
 260     else { carp "Unknown sequence $command<$_>" }
 261 }
 262
 263 # Called for each paragraph that's actually part of the POD.  We take
 264 # advantage of this opportunity to untabify the input.
 265 sub preprocess_paragraph {
 266     my $self = shift;
 267     local $_ = shift;
 268     1 while s/^(.*?)(\t+)/$1 . ' ' x (length ($2) * 8 - length ($1) % 8)/me;
 269     $_;
 270 }
 271
 272
 273 ############################################################################
 274 # Command paragraphs
 275 ############################################################################
 276
 277 # All command paragraphs take the paragraph and the line number.
 278
 279 # First level heading.
 280 sub cmd_head1 {
 281     my $self = shift;
 282     local $_ = shift;
 283     s/\s+$//;
 284     $_ = $self->interpolate ($_, shift);
 285     if ($$self{alt}) {
 286         $self->output ("\n==== $_ ====\n\n");
 287     } else {
 288         $_ .= "\n" if $$self{loose};
 289         $self->output ($_ . "\n");
 290     }
 291 }
 292
 293 # Second level heading.
 294 sub cmd_head2 {
 295     my $self = shift;
 296     local $_ = shift;
 297     s/\s+$//;
 298     $_ = $self->interpolate ($_, shift);
 299     if ($$self{alt}) {
 300         $self->output ("\n==   $_   ==\n\n");
 301     } else {
 302         $self->output (' ' x ($$self{indent} / 2) . $_ . "\n\n");
 303     }
 304 }
 305
 306 # Start a list.
 307 sub cmd_over {
 308     my $self = shift;
 309     local $_ = shift;
 310     unless (/^[-+]?\d+\s+$/) { $_ = $$self{indent} }
 311     push (@{ $$self{INDENTS} }, $$self{MARGIN});
 312     $$self{MARGIN} += ($_ + 0);
 313 }
 314
 315 # End a list.
 316 sub cmd_back {
 317     my $self = shift;
 318     $$self{MARGIN} = pop @{ $$self{INDENTS} };
 319     unless (defined $$self{MARGIN}) {
 320         carp "Unmatched =back";
 321         $$self{MARGIN} = $$self{indent};
 322     }
 323 }
 324
 325 # An individual list item.
 326 sub cmd_item {
 327     my $self = shift;
 328     if (defined $$self{ITEM}) { $self->item }
 329     local $_ = shift;
 330     s/\s+$//;
 331     $$self{ITEM} = $self->interpolate ($_);
 332 }
 333
 334 # Begin a block for a particular translator.  Setting VERBATIM triggers
 335 # special handling in textblock().
 336 sub cmd_begin {
 337     my $self = shift;
 338     local $_ = shift;
 339     my ($kind) = /^(\S+)/ or return;
 340     if ($kind eq 'text') {
 341         $$self{VERBATIM} = 1;
 342     } else {
 343         $$self{EXCLUDE} = 1;
 344     }
 345 }
 346
 347 # End a block for a particular translator.  We assume that all =begin/=end
 348 # pairs are properly closed.
 349 sub cmd_end {
 350     my $self = shift;
 351     $$self{EXCLUDE} = 0;
 352     $$self{VERBATIM} = 0;
 353 }
 354
 355 # One paragraph for a particular translator.  Ignore it unless it's intended
 356 # for text, in which case we treat it as a verbatim text block.
 357 sub cmd_for {
 358     my $self = shift;
 359     local $_ = shift;
 360     my $line = shift;
 361     return unless s/^text\b[ \t]*\n?//;
 362     $self->verbatim ($_, $line);
 363 }
 364
 365
 366 ############################################################################
 367 # Interior sequences
 368 ############################################################################
 369
 370 # The simple formatting ones.  These are here mostly so that subclasses can
 371 # override them and do more complicated things.
 372 sub seq_b { return $_[0]{alt} ? "``$_[1]''" : $_[1] }
 373 sub seq_c { return $_[0]{alt} ? "``$_[1]''" : "`$_[1]'" }
 374 sub seq_f { return $_[0]{alt} ? "\"$_[1]\"" : $_[1] }
 375 sub seq_i { return '*' . $_[1] . '*' }
 376
 377 # The complicated one.  Handle links.  Since this is plain text, we can't
 378 # actually make any real links, so this is all to figure out what text we
 379 # print out.
 380 sub seq_l {
 381     my $self = shift;
 382     local $_ = shift;
 383
 384     # Smash whitespace in case we were split across multiple lines.
 385     s/\s+/ /g;
 386
 387     # If we were given any explicit text, just output it.
 388     if (/^([^|]+)\|/) { return $1 }
 389
 390     # Okay, leading and trailing whitespace isn't important; get rid of it.
 391     s/^\s+//;
 392     s/\s+$//;
 393
 394     # Default to using the whole content of the link entry as a section
 395     # name.  Note that L<manpage/> forces a manpage interpretation, as does
 396     # something looking like L<manpage(section)>.  The latter is an
 397     # enhancement over the original Pod::Text.
 398     my ($manpage, $section) = ('', $_);
 399     if (/^(?:https?|ftp|news):/) {
 400         # a URL
 401         return $_;
 402     } elsif (/^"\s*(.*?)\s*"$/) {
 403         $section = '"' . $1 . '"';
 404     } elsif (m/^[-:.\w]+(?:\(\S+\))?$/) {
 405         ($manpage, $section) = ($_, '');
 406     } elsif (m%/%) {
 407         ($manpage, $section) = split (/\s*\/\s*/, $_, 2);
 408     }
 409
 410     my $text = '';
 411     # Now build the actual output text.
 412     if (!length $section) {
 413         $text = "the $manpage manpage" if length $manpage;
 414     } elsif ($section =~ /^[:\w]+(?:\(\))?/) {
 415         $text .= 'the ' . $section . ' entry';
 416         $text .= (length $manpage) ? " in the $manpage manpage"
 417                                    : " elsewhere in this document";
 418     } else {
 419         $section =~ s/^\"\s*//;
 420         $section =~ s/\s*\"$//;
 421         $text .= 'the section on "' . $section . '"';
 422         $text .= " in the $manpage manpage" if length $manpage;
 423     }
 424     $text;
 425 }
 426
 427
 428 ############################################################################
 429 # List handling
 430 ############################################################################
 431
 432 # This method is called whenever an =item command is complete (in other
 433 # words, we've seen its associated paragraph or know for certain that it
 434 # doesn't have one).  It gets the paragraph associated with the item as an
 435 # argument.  If that argument is empty, just output the item tag; if it
 436 # contains a newline, output the item tag followed by the newline.
 437 # Otherwise, see if there's enough room for us to output the item tag in the
 438 # margin of the text or if we have to put it on a separate line.
 439 sub item {
 440     my $self = shift;
 441     local $_ = shift;
 442     my $tag = $$self{ITEM};
 443     unless (defined $tag) {
 444         carp "item called without tag";
 445         return;
 446     }
 447     undef $$self{ITEM};
 448     my $indent = $$self{INDENTS}[-1];
 449     unless (defined $indent) { $indent = $$self{indent} }
 450     my $space = ' ' x $indent;
 451     $space =~ s/^ /:/ if $$self{alt};
 452     if (!$_ || /^\s+$/ || ($$self{MARGIN} - $indent < length ($tag) + 1)) {
 453         my $margin = $$self{MARGIN};
 454         $$self{MARGIN} = $indent;
 455         my $output = $self->reformat ($tag);
 456         $output =~ s/\n*$/\n/;
 457         $self->output ($output);
 458         $$self{MARGIN} = $margin;
 459         $self->output ($self->reformat ($_)) if /\S/;
 460     } else {
 461         $_ = $self->reformat ($_);
 462         s/^ /:/ if ($$self{alt} && $indent > 0);
 463         my $tagspace = ' ' x length $tag;
 464         s/^($space)$tagspace/$1$tag/ or warn "Bizarre space in item";
 465         $self->output ($_);
 466     }
 467 }
 468
 469
 470 ############################################################################
 471 # Output formatting
 472 ############################################################################
 473
 474 # Wrap a line, indenting by the current left margin.  We can't use
 475 # Text::Wrap because it plays games with tabs.  We can't use formline, even
 476 # though we'd really like to, because it screws up non-printing characters.
 477 # So we have to do the wrapping ourselves.
 478 sub wrap {
 479     my $self = shift;
 480     local $_ = shift;
 481     my $output = '';
 482     my $spaces = ' ' x $$self{MARGIN};
 483     my $width = $$self{width} - $$self{MARGIN};
 484     while (length > $width) {
 485         if (s/^([^\n]{0,$width})\s+// || s/^([^\n]{$width})//) {
 486             $output .= $spaces . $1 . "\n";
 487         } else {
 488             last;
 489         }
 490     }
 491     $output .= $spaces . $_;
 492     $output =~ s/\s+$/\n\n/;
 493     $output;
 494 }
 495
 496 # Reformat a paragraph of text for the current margin.  Takes the text to
 497 # reformat and returns the formatted text.
 498 sub reformat {
 499     my $self = shift;
 500     local $_ = shift;
 501
 502     # If we're trying to preserve two spaces after sentences, do some
 503     # munging to support that.  Otherwise, smash all repeated whitespace.
 504     if ($$self{sentence}) {
 505         s/ +$//mg;
 506         s/\.\n/. \n/g;
 507         s/\n/ /g;
 508         s/   +/  /g;
 509     } else {
 510         s/\s+/ /g;
 511     }
 512     $self->wrap ($_);
 513 }
 514
 515 # Output text to the output device.
 516 sub output { $_[1] =~ tr/\01/ /; print { $_[0]->output_handle } $_[1] }
 517
 518
 519 ############################################################################
 520 # Backwards compatibility
 521 ############################################################################
 522
 523 # The old Pod::Text module did everything in a pod2text() function.  This
 524 # tries to provide the same interface for legacy applications.
 525 sub pod2text {
 526     my @args;
 527
 528     # This is really ugly; I hate doing option parsing in the middle of a
 529     # module.  But the old Pod::Text module supported passing flags to its
 530     # entry function, so handle -a and -<number>.
 531     while ($_[0] =~ /^-/) {
 532         my $flag = shift;
 533         if    ($flag eq '-a')       { push (@args, alt => 1)    }
 534         elsif ($flag =~ /^-(\d+)$/) { push (@args, width => $1) }
 535         else {
 536             unshift (@_, $flag);
 537             last;
 538         }
 539     }
 540
 541     # Now that we know what arguments we're using, create the parser.
 542     my $parser = Pod::PlainText->new (@args);
 543
 544     # If two arguments were given, the second argument is going to be a file
 545     # handle.  That means we want to call parse_from_filehandle(), which
 546     # means we need to turn the first argument into a file handle.  Magic
 547     # open will handle the <&STDIN case automagically.
 548     if (defined $_[1]) {
 549         local *IN;
 550         unless (open (IN, $_[0])) {
 551             croak ("Can't open $_[0] for reading: $!\n");
 552             return;
 553         }
 554         $_[0] = \*IN;
 555         return $parser->parse_from_filehandle (@_);
 556     } else {
 557         return $parser->parse_from_file (@_);
 558     }
 559 }
 560
 561
 562 ############################################################################
 563 # Module return value and documentation
 564 ############################################################################
 565
 566 1;
 567 __END__
 568
 569 =head1 NAME
 570
 571 Pod::PlainText - Convert POD data to formatted ASCII text
 572
 573 =head1 SYNOPSIS
 574
 575     use Pod::PlainText;
 576     my $parser = Pod::PlainText->new (sentence => 0, width => 78);
 577
 578     # Read POD from STDIN and write to STDOUT.
 579     $parser->parse_from_filehandle;
 580
 581     # Read POD from file.pod and write to file.txt.
 582     $parser->parse_from_file ('file.pod', 'file.txt');
 583
 584 =head1 DESCRIPTION
 585
 586 Pod::PlainText is a module that can convert documentation in the POD format (the
 587 preferred language for documenting Perl) into formatted ASCII.  It uses no
 588 special formatting controls or codes whatsoever, and its output is therefore
 589 suitable for nearly any device.
 590
 591 As a derived class from Pod::Parser, Pod::PlainText supports the same methods and
 592 interfaces.  See L<Pod::Parser> for all the details; briefly, one creates a
 593 new parser with C<Pod::PlainText-E<gt>new()> and then calls either
 594 parse_from_filehandle() or parse_from_file().
 595
 596 new() can take options, in the form of key/value pairs, that control the
 597 behavior of the parser.  The currently recognized options are:
 598
 599 =over 4
 600
 601 =item alt
 602
 603 If set to a true value, selects an alternate output format that, among other
 604 things, uses a different heading style and marks C<=item> entries with a
 605 colon in the left margin.  Defaults to false.
 606
 607 =item indent
 608
 609 The number of spaces to indent regular text, and the default indentation for
 610 C<=over> blocks.  Defaults to 4.
 611
 612 =item loose
 613
 614 If set to a true value, a blank line is printed after a C<=head1> heading.
 615 If set to false (the default), no blank line is printed after C<=head1>,
 616 although one is still printed after C<=head2>.  This is the default because
 617 it's the expected formatting for manual pages; if you're formatting
 618 arbitrary text documents, setting this to true may result in more pleasing
 619 output.
 620
 621 =item sentence
 622
 623 If set to a true value, Pod::PlainText will assume that each sentence ends in two
 624 spaces, and will try to preserve that spacing.  If set to false, all
 625 consecutive whitespace in non-verbatim paragraphs is compressed into a
 626 single space.  Defaults to true.
 627
 628 =item width
 629
 630 The column at which to wrap text on the right-hand side.  Defaults to 76.
 631
 632 =back
 633
 634 The standard Pod::Parser method parse_from_filehandle() takes up to two
 635 arguments, the first being the file handle to read POD from and the second
 636 being the file handle to write the formatted output to.  The first defaults
 637 to STDIN if not given, and the second defaults to STDOUT.  The method
 638 parse_from_file() is almost identical, except that its two arguments are the
 639 input and output disk files instead.  See L<Pod::Parser> for the specific
 640 details.
 641
 642 =head1 DIAGNOSTICS
 643
 644 =over 4
 645
 646 =item Bizarre space in item
 647
 648 (W) Something has gone wrong in internal C<=item> processing.  This message
 649 indicates a bug in Pod::PlainText; you should never see it.
 650
 651 =item Can't open %s for reading: %s
 652
 653 (F) Pod::PlainText was invoked via the compatibility mode pod2text() interface
 654 and the input file it was given could not be opened.
 655
 656 =item Unknown escape: %s
 657
 658 (W) The POD source contained an C<EE<lt>E<gt>> escape that Pod::PlainText didn't
 659 know about.
 660
 661 =item Unknown sequence: %s
 662
 663 (W) The POD source contained a non-standard internal sequence (something of
 664 the form C<XE<lt>E<gt>>) that Pod::PlainText didn't know about.
 665
 666 =item Unmatched =back
 667
 668 (W) Pod::PlainText encountered a C<=back> command that didn't correspond to an
 669 C<=over> command.
 670
 671 =back
 672
 673 =head1 RESTRICTIONS
 674
 675 Embedded Ctrl-As (octal 001) in the input will be mapped to spaces on
 676 output, due to an internal implementation detail.
 677
 678 =head1 NOTES
 679
 680 This is a replacement for an earlier Pod::Text module written by Tom
 681 Christiansen.  It has a revamped interface, since it now uses Pod::Parser,
 682 but an interface roughly compatible with the old Pod::Text::pod2text()
 683 function is still available.  Please change to the new calling convention,
 684 though.
 685
 686 The original Pod::Text contained code to do formatting via termcap
 687 sequences, although it wasn't turned on by default and it was problematic to
 688 get it to work at all.  This rewrite doesn't even try to do that, but a
 689 subclass of it does.  Look for L<Pod::Text::Termcap|Pod::Text::Termcap>.
 690
 691 =head1 SEE ALSO
 692
 693 L<Pod::Parser|Pod::Parser>, L<Pod::Text::Termcap|Pod::Text::Termcap>,
 694 pod2text(1)
 695
 696 =head1 AUTHOR
 697
 698 Please report bugs using L<http://rt.cpan.org>.
 699
 700 Russ Allbery E<lt>rra@stanford.eduE<gt>, based I<very> heavily on the
 701 original Pod::Text by Tom Christiansen E<lt>tchrist@mox.perl.comE<gt> and
 702 its conversion to Pod::Parser by Brad Appleton
 703 E<lt>bradapp@enteract.comE<gt>.
 704
 705 =cut