summaryrefslogtreecommitdiff
path: root/Master/tlpkg/tlperl/lib/Pod/Html.pm
blob: 72b37c249ddbc221b4803ee4382bde017efff8e1 (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
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
package Pod::Html;
use strict;
require Exporter;

use vars qw($VERSION @ISA @EXPORT @EXPORT_OK);
$VERSION = 1.18;
@ISA = qw(Exporter);
@EXPORT = qw(pod2html htmlify);
@EXPORT_OK = qw(anchorify);

use Carp;
use Config;
use Cwd;
use File::Basename;
use File::Spec;
use File::Spec::Unix;
use Getopt::Long;
use Pod::Simple::Search;
BEGIN {
    if($Config{d_setlocale}) {
        require locale; import locale; # make \w work right in non-ASCII lands
    }
}

=head1 NAME

Pod::Html - module to convert pod files to HTML

=head1 SYNOPSIS

    use Pod::Html;
    pod2html([options]);

=head1 DESCRIPTION

Converts files from pod format (see L<perlpod>) to HTML format.  It
can automatically generate indexes and cross-references, and it keeps
a cache of things it knows how to cross-reference.

=head1 FUNCTIONS

=head2 pod2html

    pod2html("pod2html",
             "--podpath=lib:ext:pod:vms",
             "--podroot=/usr/src/perl",
             "--htmlroot=/perl/nmanual",
             "--recurse",
             "--infile=foo.pod",
             "--outfile=/perl/nmanual/foo.html");

pod2html takes the following arguments:

=over 4

=item backlink

    --backlink

Turns every C<head1> heading into a link back to the top of the page.
By default, no backlinks are generated.

=item cachedir

    --cachedir=name

Creates the directory cache in the given directory.

=item css

    --css=stylesheet

Specify the URL of a cascading style sheet.  Also disables all HTML/CSS
C<style> attributes that are output by default (to avoid conflicts).

=item flush

    --flush

Flushes the directory cache.

=item header

    --header
    --noheader

Creates header and footer blocks containing the text of the C<NAME>
section.  By default, no headers are generated.

=item help

    --help

Displays the usage message.

=item htmldir

    --htmldir=name

Sets the directory to which all cross references in the resulting
html file will be relative. Not passing this causes all links to be
absolute since this is the value that tells Pod::Html the root of the 
documentation tree.

Do not use this and --htmlroot in the same call to pod2html; they are
mutually exclusive.

=item htmlroot

    --htmlroot=name

Sets the base URL for the HTML files.  When cross-references are made,
the HTML root is prepended to the URL.

Do not use this if relative links are desired: use --htmldir instead.

Do not pass both this and --htmldir to pod2html; they are mutually
exclusive.

=item index

    --index
    --noindex

Generate an index at the top of the HTML file.  This is the default
behaviour.

=item infile

    --infile=name

Specify the pod file to convert.  Input is taken from STDIN if no
infile is specified.

=item outfile

    --outfile=name

Specify the HTML file to create.  Output goes to STDOUT if no outfile
is specified.

=item poderrors

    --poderrors
    --nopoderrors

Include a "POD ERRORS" section in the outfile if there were any POD 
errors in the infile. This section is included by default.

=item podpath

    --podpath=name:...:name

Specify which subdirectories of the podroot contain pod files whose
HTML converted forms can be linked to in cross references.

=item podroot

    --podroot=name

Specify the base directory for finding library pods. Default is the
current working directory.

=item quiet

    --quiet
    --noquiet

Don't display I<mostly harmless> warning messages.  These messages
will be displayed by default.  But this is not the same as C<verbose>
mode.

=item recurse

    --recurse
    --norecurse

Recurse into subdirectories specified in podpath (default behaviour).

=item title

    --title=title

Specify the title of the resulting HTML file.

=item verbose

    --verbose
    --noverbose

Display progress messages.  By default, they won't be displayed.

=back

=head2 htmlify

    htmlify($heading);

Converts a pod section specification to a suitable section specification
for HTML. Note that we keep spaces and special characters except
C<", ?> (Netscape problem) and the hyphen (writer's problem...).

=head2 anchorify

    anchorify(@heading);

Similar to C<htmlify()>, but turns non-alphanumerics into underscores.  Note
that C<anchorify()> is not exported by default.

=head1 ENVIRONMENT

Uses C<$Config{pod2html}> to setup default options.

=head1 AUTHOR

Marc Green, E<lt>marcgreen@cpan.orgE<gt>. 

Original version by Tom Christiansen, E<lt>tchrist@perl.comE<gt>.

=head1 SEE ALSO

L<perlpod>

=head1 COPYRIGHT

This program is distributed under the Artistic License.

=cut

my $Cachedir; 
my $Dircache;
my($Htmlroot, $Htmldir, $Htmlfile, $Htmlfileurl);
my($Podfile, @Podpath, $Podroot);
my $Poderrors;
my $Css;

my $Recurse;
my $Quiet;
my $Verbose;
my $Doindex;

my $Backlink;

my($Title, $Header);

my %Pages = ();                 # associative array used to find the location
                                #   of pages referenced by L<> links.

my $Curdir = File::Spec->curdir;

init_globals();

sub init_globals {
    $Cachedir = ".";            # The directory to which directory caches
                                #   will be written.

    $Dircache = "pod2htmd.tmp";

    $Htmlroot = "/";            # http-server base directory from which all
                                #   relative paths in $podpath stem.
    $Htmldir = "";              # The directory to which the html pages
                                #   will (eventually) be written.
    $Htmlfile = "";             # write to stdout by default
    $Htmlfileurl = "";          # The url that other files would use to
                                # refer to this file.  This is only used
                                # to make relative urls that point to
                                # other files.

    $Poderrors = 1;
    $Podfile = "";              # read from stdin by default
    @Podpath = ();              # list of directories containing library pods.
    $Podroot = $Curdir;         # filesystem base directory from which all
                                #   relative paths in $podpath stem.
    $Css = '';                  # Cascading style sheet
    $Recurse = 1;               # recurse on subdirectories in $podpath.
    $Quiet = 0;                 # not quiet by default
    $Verbose = 0;               # not verbose by default
    $Doindex = 1;               # non-zero if we should generate an index
    $Backlink = 0;              # no backlinks added by default
    $Header = 0;                # produce block header/footer
    $Title = '';                # title to give the pod(s)
}

sub pod2html {
    local(@ARGV) = @_;
    local $_;

    init_globals();
    parse_command_line();

    # prevent '//' in urls
    $Htmlroot = "" if $Htmlroot eq "/";
    $Htmldir =~ s#/\z##;

    if (  $Htmlroot eq ''
       && defined( $Htmldir )
       && $Htmldir ne ''
       && substr( $Htmlfile, 0, length( $Htmldir ) ) eq $Htmldir
       ) {
        # Set the 'base' url for this file, so that we can use it
        # as the location from which to calculate relative links
        # to other files. If this is '', then absolute links will
        # be used throughout.
        #$Htmlfileurl = "$Htmldir/" . substr( $Htmlfile, length( $Htmldir ) + 1);
        # Is the above not just "$Htmlfileurl = $Htmlfile"?
        $Htmlfileurl = Pod::Html::_unixify($Htmlfile);

    }

    # load or generate/cache %Pages
    unless (get_cache($Dircache, \@Podpath, $Podroot, $Recurse)) {
        # generate %Pages
        my $pwd = getcwd();
        chdir($Podroot) || 
            die "$0: error changing to directory $Podroot: $!\n";

        # find all pod modules/pages in podpath, store in %Pages
        # - callback used to remove Podroot and extension from each file
        # - laborious to allow '.' in dirnames (e.g., /usr/share/perl/5.14.1)
        Pod::Simple::Search->new->inc(0)->verbose($Verbose)->laborious(1)
            ->callback(\&_save_page)->recurse($Recurse)->survey(@Podpath);

        chdir($pwd) || die "$0: error changing to directory $pwd: $!\n";

        # cache the directory list for later use
        warn "caching directories for later use\n" if $Verbose;
        open my $cache, '>', $Dircache
            or die "$0: error open $Dircache for writing: $!\n";

        print $cache join(":", @Podpath) . "\n$Podroot\n";
        my $_updirs_only = ($Podroot =~ /\.\./) && !($Podroot =~ /[^\.\\\/]/);
        foreach my $key (keys %Pages) {
            if($_updirs_only) {
              my $_dirlevel = $Podroot;
              while($_dirlevel =~ /\.\./) {
                $_dirlevel =~ s/\.\.//;
                # Assume $Pages{$key} has '/' separators (html dir separators).
                $Pages{$key} =~ s/^[\w\s\-\.]+\///;
              }
            }
            print $cache "$key $Pages{$key}\n";
        }

        close $cache or die "error closing $Dircache: $!";
    }

    # set options for the parser
    my $parser = Pod::Simple::XHTML::LocalPodLinks->new();
    $parser->codes_in_verbatim(0);
    $parser->anchor_items(1); # the old Pod::Html always did
    $parser->backlink($Backlink); # linkify =head1 directives
    $parser->htmldir($Htmldir);
    $parser->htmlfileurl($Htmlfileurl);
    $parser->htmlroot($Htmlroot);
    $parser->index($Doindex);
    $parser->no_errata_section(!$Poderrors); # note the inverse
    $parser->output_string(\my $output); # written to file later
    $parser->pages(\%Pages);
    $parser->quiet($Quiet);
    $parser->verbose($Verbose);

    # XXX: implement default title generator in pod::simple::xhtml
    # copy the way the old Pod::Html did it
    $Title = html_escape($Title);

    # We need to add this ourselves because we use our own header, not
    # ::XHTML's header. We need to set $parser->backlink to linkify
    # the =head1 directives
    my $bodyid = $Backlink ? ' id="_podtop_"' : '';

    my $csslink = '';
    my $bodystyle = ' style="background-color: white"';
    my $tdstyle = ' style="background-color: #cccccc"';

    if ($Css) {
        $csslink = qq(\n<link rel="stylesheet" href="$Css" type="text/css" />);
        $csslink =~ s,\\,/,g;
        $csslink =~ s,(/.):,$1|,;
        $bodystyle = '';
        $tdstyle= '';
    }

    # header/footer block
    my $block = $Header ? <<END_OF_BLOCK : '';
<table border="0" width="100%" cellspacing="0" cellpadding="3">
<tr><td class="_podblock_"$tdstyle valign="middle">
<big><strong><span class="_podblock_">&nbsp;$Title</span></strong></big>
</td></tr>
</table>
END_OF_BLOCK

    # create own header/footer because of --header
    $parser->html_header(<<"HTMLHEAD");
<?xml version="1.0" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>$Title</title>$csslink
<meta http-equiv="content-type" content="text/html; charset=utf-8" />
<link rev="made" href="mailto:$Config{perladmin}" />
</head>

<body$bodyid$bodystyle>
$block
HTMLHEAD

    $parser->html_footer(<<"HTMLFOOT");
$block
</body>

</html>
HTMLFOOT

    my $input;
    unless (@ARGV && $ARGV[0]) {
        if ($Podfile and $Podfile ne '-') {
            $input = $Podfile;
        } else {
            $input = '-'; # XXX: make a test case for this
        }
    } else {
        $Podfile = $ARGV[0];
        $input = *ARGV;
    }

    warn "Converting input file $Podfile\n" if $Verbose;
    $parser->parse_file($input);

    # Write output to file
    $Htmlfile = "-" unless $Htmlfile; # stdout
    my $fhout;
    if($Htmlfile and $Htmlfile ne '-') {
        open $fhout, ">", $Htmlfile
            or die "$0: cannot open $Htmlfile file for output: $!\n";
    } else {
        open $fhout, ">-";
    }
    binmode $fhout, ":utf8";
    print $fhout $output;
    close $fhout or die "Failed to close $Htmlfile: $!";
    chmod 0644, $Htmlfile unless $Htmlfile eq '-';
}

##############################################################################

sub usage {
    my $podfile = shift;
    warn "$0: $podfile: @_\n" if @_;
    die <<END_OF_USAGE;
Usage:  $0 --help --htmlroot=<name> --infile=<name> --outfile=<name>
           --podpath=<name>:...:<name> --podroot=<name> --cachedir=<name>
           --recurse --verbose --index --norecurse --noindex

  --[no]backlink  - turn =head1 directives into links pointing to the top of
                      the page (off by default).
  --cachedir      - directory for the directory cache files.
  --css           - stylesheet URL
  --flush         - flushes the directory cache.
  --[no]header    - produce block header/footer (default is no headers).
  --help          - prints this message.
  --htmldir       - directory for resulting HTML files.
  --htmlroot      - http-server base directory from which all relative paths
                      in podpath stem (default is /).
  --[no]index     - generate an index at the top of the resulting html
                      (default behaviour).
  --infile        - filename for the pod to convert (input taken from stdin
                      by default).
  --outfile       - filename for the resulting html file (output sent to
                      stdout by default).
  --[no]poderrors - include a POD ERRORS section in the output if there were 
                      any POD errors in the input (default behavior).
  --podpath       - colon-separated list of directories containing library
                      pods (empty by default).
  --podroot       - filesystem base directory from which all relative paths
                      in podpath stem (default is .).
  --[no]quiet     - suppress some benign warning messages (default is off).
  --[no]recurse   - recurse on those subdirectories listed in podpath
                      (default behaviour).
  --title         - title that will appear in resulting html file.
  --[no]verbose   - self-explanatory (off by default).

END_OF_USAGE

}

sub parse_command_line {
    my ($opt_backlink,$opt_cachedir,$opt_css,$opt_flush,$opt_header,
        $opt_help,$opt_htmldir,$opt_htmlroot,$opt_index,$opt_infile,
        $opt_outfile,$opt_poderrors,$opt_podpath,$opt_podroot,
        $opt_quiet,$opt_recurse,$opt_title,$opt_verbose,$opt_libpods);

    unshift @ARGV, split ' ', $Config{pod2html} if $Config{pod2html};
    my $result = GetOptions(
                       'backlink!'  => \$opt_backlink,
                       'cachedir=s' => \$opt_cachedir,
                       'css=s'      => \$opt_css,
                       'flush'      => \$opt_flush,
                       'help'       => \$opt_help,
                       'header!'    => \$opt_header,
                       'htmldir=s'  => \$opt_htmldir,
                       'htmlroot=s' => \$opt_htmlroot,
                       'index!'     => \$opt_index,
                       'infile=s'   => \$opt_infile,
                       'libpods=s'  => \$opt_libpods, # deprecated
                       'outfile=s'  => \$opt_outfile,
                       'poderrors!' => \$opt_poderrors,
                       'podpath=s'  => \$opt_podpath,
                       'podroot=s'  => \$opt_podroot,
                       'quiet!'     => \$opt_quiet,
                       'recurse!'   => \$opt_recurse,
                       'title=s'    => \$opt_title,
                       'verbose!'   => \$opt_verbose,
    );
    usage("-", "invalid parameters") if not $result;

    usage("-") if defined $opt_help;    # see if the user asked for help
    $opt_help = "";                     # just to make -w shut-up.

    @Podpath  = split(":", $opt_podpath) if defined $opt_podpath;
    warn "--libpods is no longer supported" if defined $opt_libpods;

    $Backlink  =          $opt_backlink   if defined $opt_backlink;
    $Cachedir  = _unixify($opt_cachedir)  if defined $opt_cachedir;
    $Css       =          $opt_css        if defined $opt_css;
    $Header    =          $opt_header     if defined $opt_header;
    $Htmldir   = _unixify($opt_htmldir)   if defined $opt_htmldir;
    $Htmlroot  = _unixify($opt_htmlroot)  if defined $opt_htmlroot;
    $Doindex   =          $opt_index      if defined $opt_index;
    $Podfile   = _unixify($opt_infile)    if defined $opt_infile;
    $Htmlfile  = _unixify($opt_outfile)   if defined $opt_outfile;
    $Poderrors =          $opt_poderrors  if defined $opt_poderrors;
    $Podroot   = _unixify($opt_podroot)   if defined $opt_podroot;
    $Quiet     =          $opt_quiet      if defined $opt_quiet;
    $Recurse   =          $opt_recurse    if defined $opt_recurse;
    $Title     =          $opt_title      if defined $opt_title;
    $Verbose   =          $opt_verbose    if defined $opt_verbose;

    warn "Flushing directory caches\n"
        if $opt_verbose && defined $opt_flush;
    $Dircache = "$Cachedir/pod2htmd.tmp";
    if (defined $opt_flush) {
        1 while unlink($Dircache);
    }
}

my $Saved_Cache_Key;

sub get_cache {
    my($dircache, $podpath, $podroot, $recurse) = @_;
    my @cache_key_args = @_;

    # A first-level cache:
    # Don't bother reading the cache files if they still apply
    # and haven't changed since we last read them.

    my $this_cache_key = cache_key(@cache_key_args);
    return 1 if $Saved_Cache_Key and $this_cache_key eq $Saved_Cache_Key;
    $Saved_Cache_Key = $this_cache_key;

    # load the cache of %Pages if possible.  $tests will be
    # non-zero if successful.
    my $tests = 0;
    if (-f $dircache) {
        warn "scanning for directory cache\n" if $Verbose;
        $tests = load_cache($dircache, $podpath, $podroot);
    }

    return $tests;
}

sub cache_key {
    my($dircache, $podpath, $podroot, $recurse) = @_;
    return join('!',$dircache,$recurse,@$podpath,$podroot,stat($dircache));
}

#
# load_cache - tries to find if the cache stored in $dircache is a valid
#  cache of %Pages.  if so, it loads them and returns a non-zero value.
#
sub load_cache {
    my($dircache, $podpath, $podroot) = @_;
    my $tests = 0;
    local $_;

    warn "scanning for directory cache\n" if $Verbose;
    open(my $cachefh, '<', $dircache) ||
        die "$0: error opening $dircache for reading: $!\n";
    $/ = "\n";

    # is it the same podpath?
    $_ = <$cachefh>;
    chomp($_);
    $tests++ if (join(":", @$podpath) eq $_);

    # is it the same podroot?
    $_ = <$cachefh>;
    chomp($_);
    $tests++ if ($podroot eq $_);

    # load the cache if its good
    if ($tests != 2) {
        close($cachefh);
        return 0;
    }

    warn "loading directory cache\n" if $Verbose;
    while (<$cachefh>) {
        /(.*?) (.*)$/;
        $Pages{$1} = $2;
    }

    close($cachefh);
    return 1;
}


#
# html_escape: make text safe for HTML
#
sub html_escape {
    my $rest = $_[0];
    $rest   =~ s/&/&amp;/g;
    $rest   =~ s/</&lt;/g;
    $rest   =~ s/>/&gt;/g;
    $rest   =~ s/"/&quot;/g;
    # &apos; is only in XHTML, not HTML4.  Be conservative
    #$rest   =~ s/'/&apos;/g;
    return $rest;
}

#
# htmlify - converts a pod section specification to a suitable section
# specification for HTML. Note that we keep spaces and special characters
# except ", ? (Netscape problem) and the hyphen (writer's problem...).
#
sub htmlify {
    my( $heading) = @_;
    $heading =~ s/(\s+)/ /g;
    $heading =~ s/\s+\Z//;
    $heading =~ s/\A\s+//;
    # The hyphen is a disgrace to the English language.
    # $heading =~ s/[-"?]//g;
    $heading =~ s/["?]//g;
    $heading = lc( $heading );
    return $heading;
}

#
# similar to htmlify, but turns non-alphanumerics into underscores
#
sub anchorify {
    my ($anchor) = @_;
    $anchor = htmlify($anchor);
    $anchor =~ s/\W/_/g;
    return $anchor;
}

#
# store POD files in %Pages
#
sub _save_page {
    my ($modspec, $modname) = @_;

    # Remove Podroot from path
    $modspec = $Podroot eq File::Spec->curdir
               ? File::Spec->abs2rel($modspec)
               : File::Spec->abs2rel($modspec,
                                     File::Spec->canonpath($Podroot));

    # Convert path to unix style path
    $modspec = Pod::Html::_unixify($modspec);

    my ($file, $dir) = fileparse($modspec, qr/\.[^.]*/); # strip .ext
    $Pages{$modname} = $dir.$file;
}

sub _unixify {
    my $full_path = shift;
    return '' unless $full_path;
    return $full_path if $full_path eq '/';

    my ($vol, $dirs, $file) = File::Spec->splitpath($full_path);
    my @dirs = $dirs eq File::Spec->curdir()
               ? (File::Spec::Unix->curdir())
               : File::Spec->splitdir($dirs);
    if (defined($vol) && $vol) {
        $vol =~ s/:$// if $^O eq 'VMS';
        $vol = uc $vol if $^O eq 'MSWin32';

        if( $dirs[0] ) {
            unshift @dirs, $vol;
        }
        else {
            $dirs[0] = $vol;
        }
    }
    unshift @dirs, '' if File::Spec->file_name_is_absolute($full_path);
    return $file unless scalar(@dirs);
    $full_path = File::Spec::Unix->catfile(File::Spec::Unix->catdir(@dirs),
                                           $file);
    $full_path =~ s|^\/|| if $^O eq 'MSWin32'; # C:/foo works, /C:/foo doesn't
    $full_path =~ s/\^\././g if $^O eq 'VMS'; # unescape dots
    return $full_path;
}

package Pod::Simple::XHTML::LocalPodLinks;
use strict;
use warnings;
use base 'Pod::Simple::XHTML';

use File::Spec;
use File::Spec::Unix;

__PACKAGE__->_accessorize(
 'htmldir',
 'htmlfileurl',
 'htmlroot',
 'pages', # Page name => relative/path/to/page from root POD dir
 'quiet',
 'verbose',
);

sub resolve_pod_page_link {
    my ($self, $to, $section) = @_;

    return undef unless defined $to || defined $section;
    if (defined $section) {
        $section = '#' . $self->idify($section, 1);
        return $section unless defined $to;
    } else {
        $section = '';
    }

    my $path; # path to $to according to %Pages
    unless (exists $self->pages->{$to}) {
        # Try to find a POD that ends with $to and use that.
        # e.g., given L<XHTML>, if there is no $Podpath/XHTML in %Pages,
        # look for $Podpath/*/XHTML in %Pages, with * being any path,
        # as a substitute (e.g., $Podpath/Pod/Simple/XHTML)
        my @matches;
        foreach my $modname (keys %{$self->pages}) {
            push @matches, $modname if $modname =~ /::\Q$to\E\z/;
        }

        if ($#matches == -1) {
            warn "Cannot find \"$to\" in podpath: " . 
                 "cannot find suitable replacement path, cannot resolve link\n"
                 unless $self->quiet;
            return '';
        } elsif ($#matches == 0) {
            warn "Cannot find \"$to\" in podpath: " .
                 "using $matches[0] as replacement path to $to\n" 
                 unless $self->quiet;
            $path = $self->pages->{$matches[0]};
        } else {
            warn "Cannot find \"$to\" in podpath: " .
                 "more than one possible replacement path to $to, " .
                 "using $matches[-1]\n" unless $self->quiet;
            # Use [-1] so newer (higher numbered) perl PODs are used
            $path = $self->pages->{$matches[-1]};
        }
    } else {
        $path = $self->pages->{$to};
    }

    my $url = File::Spec::Unix->catfile(Pod::Html::_unixify($self->htmlroot),
                                        $path);

    if ($self->htmlfileurl ne '') {
        # then $self->htmlroot eq '' (by definition of htmlfileurl) so
        # $self->htmldir needs to be prepended to link to get the absolute path
        # that will be relativized
        $url = relativize_url(
            File::Spec::Unix->catdir(Pod::Html::_unixify($self->htmldir), $url),
            $self->htmlfileurl # already unixified
        );
    }

    return $url . ".html$section";
}

#
# relativize_url - convert an absolute URL to one relative to a base URL.
# Assumes both end in a filename.
#
sub relativize_url {
    my ($dest, $source) = @_;

    # Remove each file from its path
    my ($dest_volume, $dest_directory, $dest_file) =
        File::Spec::Unix->splitpath( $dest );
    $dest = File::Spec::Unix->catpath( $dest_volume, $dest_directory, '' );

    my ($source_volume, $source_directory, $source_file) =
        File::Spec::Unix->splitpath( $source );
    $source = File::Spec::Unix->catpath( $source_volume, $source_directory, '' );

    my $rel_path = '';
    if ($dest ne '') {
       $rel_path = File::Spec::Unix->abs2rel( $dest, $source );
    }

    if ($rel_path ne '' && substr( $rel_path, -1 ) ne '/') {
        $rel_path .= "/$dest_file";
    } else {
        $rel_path .= "$dest_file";
    }

    return $rel_path;
}

1;