/usr/lib/x86_64-linux-gnu/perl5/5.20/HTML/HeadParser.pm is in libhtml-parser-perl 3.71-1+b3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | package HTML::HeadParser;
=head1 NAME
HTML::HeadParser - Parse <HEAD> section of a HTML document
=head1 SYNOPSIS
require HTML::HeadParser;
$p = HTML::HeadParser->new;
$p->parse($text) and print "not finished";
$p->header('Title') # to access <title>....</title>
$p->header('Content-Base') # to access <base href="http://...">
$p->header('Foo') # to access <meta http-equiv="Foo" content="...">
$p->header('X-Meta-Author') # to access <meta name="author" content="...">
$p->header('X-Meta-Charset') # to access <meta charset="...">
=head1 DESCRIPTION
The C<HTML::HeadParser> is a specialized (and lightweight)
C<HTML::Parser> that will only parse the E<lt>HEAD>...E<lt>/HEAD>
section of an HTML document. The parse() method
will return a FALSE value as soon as some E<lt>BODY> element or body
text are found, and should not be called again after this.
Note that the C<HTML::HeadParser> might get confused if raw undecoded
UTF-8 is passed to the parse() method. Make sure the strings are
properly decoded before passing them on.
The C<HTML::HeadParser> keeps a reference to a header object, and the
parser will update this header object as the various elements of the
E<lt>HEAD> section of the HTML document are recognized. The following
header fields are affected:
=over 4
=item Content-Base:
The I<Content-Base> header is initialized from the E<lt>base
href="..."> element.
=item Title:
The I<Title> header is initialized from the E<lt>title>...E<lt>/title>
element.
=item Isindex:
The I<Isindex> header will be added if there is a E<lt>isindex>
element in the E<lt>head>. The header value is initialized from the
I<prompt> attribute if it is present. If no I<prompt> attribute is
given it will have '?' as the value.
=item X-Meta-Foo:
All E<lt>meta> elements containing a C<name> attribute will result in
headers using the prefix C<X-Meta-> appended with the value of the
C<name> attribute as the name of the header, and the value of the
C<content> attribute as the pushed header value.
E<lt>meta> elements containing a C<http-equiv> attribute will result
in headers as in above, but without the C<X-Meta-> prefix in the
header name.
E<lt>meta> elements containing a C<charset> attribute will result in
an C<X-Meta-Charset> header, using the value of the C<charset>
attribute as the pushed header value.
The ':' character can't be represented in header field names, so
if the meta element contains this char it's substituted with '-'
before forming the field name.
=back
=head1 METHODS
The following methods (in addition to those provided by the
superclass) are available:
=over 4
=cut
require HTML::Parser;
@ISA = qw(HTML::Parser);
use HTML::Entities ();
use strict;
use vars qw($VERSION $DEBUG);
#$DEBUG = 1;
$VERSION = "3.71";
=item $hp = HTML::HeadParser->new
=item $hp = HTML::HeadParser->new( $header )
The object constructor. The optional $header argument should be a
reference to an object that implement the header() and push_header()
methods as defined by the C<HTTP::Headers> class. Normally it will be
of some class that is a or delegates to the C<HTTP::Headers> class.
If no $header is given C<HTML::HeadParser> will create an
C<HTTP::Headers> object by itself (initially empty).
=cut
sub new
{
my($class, $header) = @_;
unless ($header) {
require HTTP::Headers;
$header = HTTP::Headers->new;
}
my $self = $class->SUPER::new(api_version => 3,
start_h => ["start", "self,tagname,attr"],
end_h => ["end", "self,tagname"],
text_h => ["text", "self,text"],
ignore_elements => [qw(script style)],
);
$self->{'header'} = $header;
$self->{'tag'} = ''; # name of active element that takes textual content
$self->{'text'} = ''; # the accumulated text associated with the element
$self;
}
=item $hp->header;
Returns a reference to the header object.
=item $hp->header( $key )
Returns a header value. It is just a shorter way to write
C<$hp-E<gt>header-E<gt>header($key)>.
=cut
sub header
{
my $self = shift;
return $self->{'header'} unless @_;
$self->{'header'}->header(@_);
}
sub as_string # legacy
{
my $self = shift;
$self->{'header'}->as_string;
}
sub flush_text # internal
{
my $self = shift;
my $tag = $self->{'tag'};
my $text = $self->{'text'};
$text =~ s/^\s+//;
$text =~ s/\s+$//;
$text =~ s/\s+/ /g;
print "FLUSH $tag => '$text'\n" if $DEBUG;
if ($tag eq 'title') {
my $decoded;
$decoded = utf8::decode($text) if $self->utf8_mode && defined &utf8::decode;
HTML::Entities::decode($text);
utf8::encode($text) if $decoded;
$self->{'header'}->push_header(Title => $text);
}
$self->{'tag'} = $self->{'text'} = '';
}
# This is an quote from the HTML3.2 DTD which shows which elements
# that might be present in a <HEAD>...</HEAD>. Also note that the
# <HEAD> tags themselves might be missing:
#
# <!ENTITY % head.content "TITLE & ISINDEX? & BASE? & STYLE? &
# SCRIPT* & META* & LINK*">
#
# <!ELEMENT HEAD O O (%head.content)>
#
# From HTML 4.01:
#
# <!ENTITY % head.misc "SCRIPT|STYLE|META|LINK|OBJECT">
# <!ENTITY % head.content "TITLE & BASE?">
# <!ELEMENT HEAD O O (%head.content;) +(%head.misc;)>
#
# From HTML 5 as of WD-html5-20090825:
#
# One or more elements of metadata content, [...]
# => base, command, link, meta, noscript, script, style, title
sub start
{
my($self, $tag, $attr) = @_; # $attr is reference to a HASH
print "START[$tag]\n" if $DEBUG;
$self->flush_text if $self->{'tag'};
if ($tag eq 'meta') {
my $key = $attr->{'http-equiv'};
if (!defined($key) || !length($key)) {
if ($attr->{name}) {
$key = "X-Meta-\u$attr->{name}";
} elsif ($attr->{charset}) { # HTML 5 <meta charset="...">
$key = "X-Meta-Charset";
$self->{header}->push_header($key => $attr->{charset});
return;
} else {
return;
}
}
$key =~ s/:/-/g;
$self->{'header'}->push_header($key => $attr->{content});
} elsif ($tag eq 'base') {
return unless exists $attr->{href};
(my $base = $attr->{href}) =~ s/^\s+//; $base =~ s/\s+$//; # HTML5
$self->{'header'}->push_header('Content-Base' => $base);
} elsif ($tag eq 'isindex') {
# This is a non-standard header. Perhaps we should just ignore
# this element
$self->{'header'}->push_header(Isindex => $attr->{prompt} || '?');
} elsif ($tag =~ /^(?:title|noscript|object|command)$/) {
# Just remember tag. Initialize header when we see the end tag.
$self->{'tag'} = $tag;
} elsif ($tag eq 'link') {
return unless exists $attr->{href};
# <link href="http:..." rel="xxx" rev="xxx" title="xxx">
my $href = delete($attr->{href});
$href =~ s/^\s+//; $href =~ s/\s+$//; # HTML5
my $h_val = "<$href>";
for (sort keys %{$attr}) {
next if $_ eq "/"; # XHTML junk
$h_val .= qq(; $_="$attr->{$_}");
}
$self->{'header'}->push_header(Link => $h_val);
} elsif ($tag eq 'head' || $tag eq 'html') {
# ignore
} else {
# stop parsing
$self->eof;
}
}
sub end
{
my($self, $tag) = @_;
print "END[$tag]\n" if $DEBUG;
$self->flush_text if $self->{'tag'};
$self->eof if $tag eq 'head';
}
sub text
{
my($self, $text) = @_;
print "TEXT[$text]\n" if $DEBUG;
unless ($self->{first_chunk}) {
# drop Unicode BOM if found
if ($self->utf8_mode) {
$text =~ s/^\xEF\xBB\xBF//;
}
else {
$text =~ s/^\x{FEFF}//;
}
$self->{first_chunk}++;
}
my $tag = $self->{tag};
if (!$tag && $text =~ /\S/) {
# Normal text means start of body
$self->eof;
return;
}
return if $tag ne 'title';
$self->{'text'} .= $text;
}
BEGIN {
*utf8_mode = sub { 1 } unless HTML::Entities::UNICODE_SUPPORT;
}
1;
__END__
=back
=head1 EXAMPLE
$h = HTTP::Headers->new;
$p = HTML::HeadParser->new($h);
$p->parse(<<EOT);
<title>Stupid example</title>
<base href="http://www.linpro.no/lwp/">
Normal text starts here.
EOT
undef $p;
print $h->title; # should print "Stupid example"
=head1 SEE ALSO
L<HTML::Parser>, L<HTTP::Headers>
The C<HTTP::Headers> class is distributed as part of the
I<libwww-perl> package. If you don't have that distribution installed
you need to provide the $header argument to the C<HTML::HeadParser>
constructor with your own object that implements the documented
protocol.
=head1 COPYRIGHT
Copyright 1996-2001 Gisle Aas. All rights reserved.
This library is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
=cut
|