## -*- Perl -*-# $Id: html.pl,v 1.32.4.2 2002/06/17 05:02:59 knok Exp $# Copyright (C) 1997-1999 Satoru Takabayashi All rights reserved.# Copyright (C) 2000 Namazu Project All rights reserved.#     This is free software with ABSOLUTELY NO WARRANTY.##  This program is free software; you can redistribute it and/or modify#  it under the terms of the GNU General Public License as published by#  the Free Software Foundation; either versions 2, or (at your option)#  any later version.# #  This program is distributed in the hope that it will be useful#  but WITHOUT ANY WARRANTY; without even the implied warranty of#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the#  GNU General Public License for more details.##  You should have received a copy of the GNU General Public License#  along with this program; if not, write to the Free Software#  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA#  02111-1307, USA##  This file must be encoded in EUC-JP encoding#package html;use strict;require 'gfilter.pl';my $EMBEDDED_FILE = '\.(asp|jsp|php[3s]?|phtml)(?:\.gz)?';sub mediatype() {    return ('text/html');}sub status() {    return 'yes';}sub recursive() {    return 0;}sub pre_codeconv() {    return 1;}sub post_codeconv () {    return 0;}sub add_magic ($) {    return;}sub filter ($$$$$) {    my ($orig_cfile, $cont, $weighted_str, $headings, $fields)      = @_;    my $cfile = defined $orig_cfile ? $$orig_cfile : '';    util::vprint("Processing html file ...\n");    if ($var::Opt{'robotexclude'}) {	my $err = isexcluded($cont);	return $err if $err;    }    if ($cfile =~ /($EMBEDDED_FILE)$/o) {       embedded_filter($cont);    }    html_filter($cont, $weighted_str, $fields, $headings);        gfilter::line_adjust_filter($cont);    gfilter::line_adjust_filter($weighted_str);    gfilter::white_space_adjust_filter($cont);    gfilter::show_filter_debug_info($cont, $weighted_str,			   $fields, $headings);    return undef;}# Check wheter or not the given URI is excluded.sub isexcluded ($) {    my ($contref) = @_;    my $err = undef;    if ($$contref =~ /META\s+NAME\s*=\s*([\'\"]?)ROBOTS\1\s+[^>]*	CONTENT\s*=\s*([\'\"]?).*?(NOINDEX|NONE).*?\2[^>]*>/ix)  #"    {	$err = _("is excluded because of <meta name=\"robots\" ...>");    }    return $err;}sub html_filter ($$$$) {    my ($contref, $weighted_str, $fields, $headings) = @_;    html::escape_lt_gt($contref);    $fields->{'title'} = html::get_title($contref, $weighted_str);    html::get_author($contref, $fields);    html::get_meta_tags($contref, $weighted_str, $fields);    html::get_img_alt($contref);    html::get_table_summary($contref);    html::get_title_attr($contref);    html::normalize_html_element($contref);    html::erase_above_body($contref);    html::remove_comments($contref);    html::weight_element($contref, $weighted_str, $headings);    html::remove_html_elements($contref);    # restore entities of each content.    html::decode_entity($contref);    html::decode_entity($weighted_str);    html::decode_entity($headings);    for my $key (keys %{$fields}) {	html::decode_entity(\$fields->{$key});    }}# Get rid of HTML-embedded codessub embedded_filter ($) {    my ($contref) = @_;    # handle with ASP,JSP,PHP,VBScript,JScript and JavaScript.    $$contref =~ s/<%.*?%>//gs;    $$contref =~ s/<\?.*?\?>//gs;    $$contref =~ s/<asp:.*?\/>//gs;    $$contref =~ s/<jsp:.*?\/>//gs;    $$contref =~ s/<script.*>.*<\/script>//igs;}# Convert independent < > s into entity references for escaping.# Substitute twice for safe.sub escape_lt_gt ($) {    my ($contref) = @_;    $$contref =~ s/\s<\s/ &lt; /g;    $$contref =~ s/\s>\s/ &gt; /g;    $$contref =~ s/\s<\s/ &lt; /g;    $$contref =~ s/\s>\s/ &gt; /g;}sub get_author ($$) {    my ($contref, $fields) = @_;    # <LINK REV=MADE HREF="mailto:ccsatoru@vega.aichi-u.ac.jp">    if ($$contref =~ m!<LINK\s[^>]*?HREF=([\"\'])mailto:(.*?)\1\s*>!i) { #"	    $fields->{'author'} = $2;    } elsif ($$contref =~ m!.*<ADDRESS[^>]*>([^<]*?)</ADDRESS>!i) {	my $tmp = $1;#	$tmp =~ s/\s//g;	if ($tmp =~ /\b([\w\.\-]+\@[\w\.\-]+(?:\.[\w\.\-]+)+)\b/) {	    $fields->{'author'} = $1;	}    }}# Get title from <title>..</title># It's okay to exits two or more <title>...</TITLE>. # First one will be retrieved.sub get_title ($$) {    my ($contref, $weighted_str) = @_;    my $title = '';        if ($$contref =~ s!<TITLE[^>]*>([^<]+)</TITLE>!!i) {	$title = $1;	$title =~ s/\s+/ /g;	$title =~ s/^\s+//;	$title =~ s/\s+$//;	my $weight = $conf::Weight{'html'}->{'title'};	$$weighted_str .= "\x7f$weight\x7f$title\x7f/$weight\x7f\n";    } else {	$title = $conf::NO_TITLE;    }    return $title;}# get foo bar from <META NAME="keywords|description" CONTENT="foo bar"> sub get_meta_tags ($$$) {    my ($contref, $weighted_str, $fields) = @_;        # <meta name="keywords" content="foo bar baz">    my $weight = $conf::Weight{'metakey'};    $$weighted_str .= "\x7f$weight\x7f$3\x7f/$weight\x7f\n" 	if $$contref =~ /<meta\s+name\s*=\s*([\'\"]?) #"	    keywords\1\s+[^>]*content\s*=\s*([\'\"]?)([^>]*?)\2[^>]*>/ix; #"    # <meta name="description" content="foo bar baz">    $$weighted_str .= "\x7f$weight\x7f$3\x7f/$weight\x7f\n" 	if $$contref =~ /<meta\s+name\s*=\s*([\'\"]?)description #"	    \1\s+[^>]*content\s*=\s*([\'\"]?)([^>]*?)\2[^>]*>/ix; #"    if ($var::Opt{'meta'}) {	my @keys = split '\|', $conf::META_TAGS;	for my $key (@keys) {	    while ($$contref =~ /<meta\s+name\s*=\s*([\'\"]?)$key #"	       \1\s+[^>]*content\s*=\s*([\'\"]?)([^>]*?)\2[^>]*>/gix) 	    {		$fields->{$key} .= $3 . " ";	    }	    util::dprint("meta: $key: $fields->{$key}\n") 		if defined $fields->{$key};	}    }}# Get foo from <IMG ... ALT="foo"># It's not to handle HTML strictly.sub get_img_alt ($) {    my ($contref) = @_;    $$contref =~ s/<IMG[^>]*\s+ALT\s*=\s*[\"\']?([^\"\']*)[\"\']?[^>]*>/ $1 /gi; #"}# Get foo from <TABLE ... SUMMARY="foo">sub get_table_summary ($) {    my ($contref) = @_;    $$contref =~ s/<TABLE[^>]*\s+SUMMARY\s*=\s*[\"\']?([^\"\']*)[\"\']?[^>]*>/ $1 /gi; #"}# Get foo from <XXX ... TITLE="foo">sub get_title_attr ($) {    my ($contref) = @_;    $$contref =~ s/<[A-Z]+[^>]*\s+TITLE\s*=\s*[\"\']?([^\"\']*)[\"\']?[^>]*>/ $1 /gi; #"}# Normalize elements like: <A HREF...> -> <A>sub normalize_html_element ($) {    my ($contref) = @_;    $$contref =~ s/<([!\w]+)\s+[^>]*>/<$1>/g;}# Remove contents above <body>.sub erase_above_body ($) {    my ($contref) = @_;    $$contref =~ s/^.*<body>//is;}# remove all comments. it's not perfect but almost works.sub remove_comments ($) {    my ($contref) = @_;    # remove all comments    $$contref =~ s/<!--.*?-->//gs;}# Weight a score of a keyword in a given text using %conf::Weight hash.# This process make the text be surround by temporary tags # \x7fXX\x7f and \x7f/XX\x7f. XX represents score.# Sort keys of %conf::Weight for processing <a> first.# Because <a> has a tendency to be inside of other tags.# Thus, it does'not processing for nexted tags strictly.# Moreover, it does special processing for <h[1-6]> for summarization.sub weight_element ($$$ ) {    my ($contref, $weighted_str, $headings) = @_;    for my $element (sort keys(%{$conf::Weight{'html'}})) {	my $tmp = "";	$$contref =~ s!<($element)>(.*?)</$element>!weight_element_sub($1, $2, \$tmp)!gies;	$$headings .= $tmp if $element =~ /^H[1-6]$/i && ! $var::Opt{'noheadabst'} 	    && $tmp;	my $weight = $element =~ /^H[1-6]$/i && ! $var::Opt{'noheadabst'} ? 	    $conf::Weight{'html'}->{$element} : $conf::Weight{'html'}->{$element} - 1;	$$weighted_str .= "\x7f$weight\x7f$tmp\x7f/$weight\x7f\n" if $tmp;    }}sub weight_element_sub ($$$) {    my ($element, $text, $tmp) = @_;    my $space = element_space($element);    $text =~ s/<[^>]*>//g;    $$tmp .= "$text " if (length($text)) < $conf::INVALID_LENG;    $element =~ /^H[1-6]$/i && ! $var::Opt{'noheadabst'}  ? " " : "$space$text$space";}# determine whether a given element should be delete or be substituted with spacesub element_space ($) {    $_[0] =~ /^($conf::NON_SEPARATION_ELEMENTS)$/io ? "" : " ";}# remove all HTML elements. it's not perfect but almost works.sub remove_html_elements ($) {    my ($contref) = @_;    # remove all elements    $$contref =~ s!</?([A-Z]\w*)(?:\s+[A-Z]\w*(?:\s*=\s*(?:(["']).*?\2|[\w\-.]+))?)*\s*>!element_space($1)!gsixe;}# Decode a numberd entity. Exclude an invalid number.sub decode_numbered_entity ($) {    my ($num) = @_;    return ""	if $num >= 0 && $num <= 8 ||  $num >= 11 && $num <= 31 || $num >=127;    sprintf ("%c",$num);}# Decode an entity. Ignore characters of right half of ISO-8859-1.# Because it can't be handled in EUC encoding.# This function provides sequential entities like: &quot &lt &gt;sub decode_entity ($) {    my ($text) = @_;    return unless defined($$text);    $$text =~ s/&#(\d{2,3})[;\s]/decode_numbered_entity($1)/ge;    $$text =~ s/&#x([\da-f]+)[;\s]/decode_numbered_entity(hex($1))/gei;    $$text =~ s/&quot[;\s]/\"/g; #"    $$text =~ s/&amp[;\s]/&/g;    $$text =~ s/&lt[;\s]/</g;    $$text =~ s/&gt[;\s]/>/g;    $$text =~ s/&nbsp[;\s]/ /g;}# encode entities: only '<', '>', and '&'sub encode_entity ($) {    my ($tmp) = @_;    $$tmp =~ s/&/&amp;/g;    # &amp; should be processed first    $$tmp =~ s/</&lt;/g;    $$tmp =~ s/>/&gt;/g;    $$tmp;}1;