Issue comparing Japanese characters

Question

I am struggling to use HTML::TokeParser to parse an HTML document that contains Japanese characters.

Here is my code:

use utf8;

use Encode qw(decode encode is_utf8);
use Encode::Guess;
use Data::Dumper;
use LWP::UserAgent;
use HTTP::Cookies;
use Cwd;
use HTML::TokeParser;

my $local_dir = getcwd;

my $browser = LWP::UserAgent->new();

my $cookie_jar = HTTP::Cookies->new(
   file     => $local_dir . "/cookies.lwp",
   autosave => 1,
);

$browser->cookie_jar( $cookie_jar );

push @{ $browser->requests_redirectable }, 'POST';
$browser->requests_redirectable;

my $response = $browser->get("http://www.yahoo.co.jp/");
my $html = $response->content;
print $html;
utf8::decode($html);

my $p = HTML::TokeParser->new( \$html );

# dispatch table with subs to handle the different types of tokens

my %dispatch = (
   S  => sub { $_[0]->[4] }, # Start tag
   E  => sub { $_[0]->[2] }, # End tag
   T  => sub { $_[0]->[1] }, # Text
   C  => sub { $_[0]->[1] }, # Comment
   D  => sub { $_[0]->[1] }, # Declaration
   PI => sub { $_[0]->[2] }, # Process Instruction
);

while ( my $token = $p->get_tag('a') ) {
        print $p->get_trimmed_text if $p->get_trimmed_text eq '社会的責任';
        print "\n";
}

This doesn't display anything on my terminal, but if I just do a print $p->get_trimmed_text then the output is OK.

Here are a few hexdump lines corresponding to print $p->get_trimmed_text:

0000000 490a 746e 7265 656e 2074 7845 6c70 726f
0000010 7265 81e3 e4ae 92ba 8fe6 e89b a8a1 a4e7
0000020 e3ba ab81 81e3 e3a4 8481 81e3 0aa6 9fe7
0000030 e5b3 9db7 81e9 e3bc 8982 9be5 e5bd 8586
0000040 a4e5 e396 ae81 83e3 e397 ad83 82e3 e3b4
0000050 ab83 83e3 e395 a182 83e3 e3bc 8c81 86e7
0000060 e68a ac9c 94e6 e6af b48f 320a e334 ab82
0000070 89e6 e380 ae81 b4e7 e885 8991 90e5 e68d
0000080 8089 82e3 e692 a597 b8e5 e3b0 8a82 82e3
0000090 e3b3 bc83 82e3 e4b9 95bb abe7 e38b a681
00000a0 81e3 e7a7 b9b4 bbe4 0a8b 83e3 e39e af82
00000b0 83e3 e389 8a83 83e3 e3ab 8983 82e3 e384
00000c0 8783 83e3 e38b bc83 82e3 e3ba ae81 81e3
00000d0 e58a 97be 81e3 e3aa af82 83e3 e3bc 9d83
00000e0 83e3 e9b3 8d85 bfe4 0aa1 a8e8 e88e 96ab
00000f0 bce4 e39a 8c80 83e3 e392 a983 83e3 e3aa
0000100 bc83 b0e6 e58f 9d8b 88e5 e3a9 8d80 3235
0000110 e525 9986 9ce7 4e9f 5745 e50a a7a4 98e9

It seems like the comparison does not work.

I can use only HTML::TokeParser because that's the only module installed on the server and I can't install anything else.

Answer 1

Please see ikegami's answer. Mine is just an alternate approach which does not address the actual issue with your code.

---

Unicode::Collate to the rescue!

Note that I added below in your code.

use Unicode::Collate;
use open qw/:std :utf8/;
my $Collator = Unicode::Collate->new();
sub compare_strs
{
    my ( $str1, $str2 ) = @_;
    # Treat vars as strings by quoting. 
    # Possibly incorrect/irrelevant approach. 
    return $Collator->cmp("$str1", "$str2");
}

Note: compare_strs subroutine will return 1 (when $str1 is greater than $str2) or 0 (when $str1 is equal to $str2) or -1 (when $str1 is less than $str2).

Below is the complete working code:

use strict;
use warnings;
use utf8;
use Unicode::Collate;
use open qw/:std :utf8/;
use Encode qw(decode encode is_utf8);
use Encode::Guess;
use Data::Dumper;
use LWP::UserAgent;
use HTTP::Cookies;
use Cwd;
use HTML::TokeParser;
my $local_dir = getcwd;
my $browser = LWP::UserAgent->new();
my $cookie_jar = HTTP::Cookies->new(
   file     => $local_dir . "/cookies.lwp",
   autosave => 1,
);
$browser->cookie_jar( $cookie_jar );
push @{ $browser->requests_redirectable }, 'POST';
$browser->requests_redirectable;
my $Collator = Unicode::Collate->new();
sub compare_strs
{
    my ( $str1, $str2 ) = @_;
    # Treat vars as strings by quoting. 
    # Possibly incorrect/irrelevant approach. 
    return $Collator->cmp("$str1", "$str2");
}
my $response   = $browser->get("http://www.yahoo.co.jp/");
my $html = $response->content;
#print $html;
utf8::decode($html);
my $p = HTML::TokeParser->new( \$html );

# dispatch table with subs to handle the different types of tokens
my %dispatch = (
   S  => sub { $_[0]->[4] }, # Start tag
   E  => sub { $_[0]->[2] }, # End tag
   T  => sub { $_[0]->[1] }, # Text
   C  => sub { $_[0]->[1] }, # Comment
   D  => sub { $_[0]->[1] }, # Declaration
   PI => sub { $_[0]->[2] }, # Process Instruction
);

my $string = '社会的責任';
while ( my $token = $p->get_tag('a') ) {
        my $text = $p->get_trimmed_text;
        unless (compare_strs($text, $string)){
          print $text;
          print "\n";
        }
}

Output:

chankeypathak@perl:~/Desktop$ perl test.pl 
社会的責任