#!/usr/bin/perl

use LWP::UserAgent;
use URI::Escape;
use XML::Simple;
use HTTP::Status;
binmode(STDOUT, ":utf8");

my $top_url    = 'http://xisbn.worldcat.org/webservices/xid/isbn/';
my $tail_url   = '?method=getEditions&format=xml&fl=form,year,lang,ed';
use constant TIMEOUT_DEF => 2;
use constant TIMEOUT_MAX => 10;
use constant LANG => eng;     # eng => 英語, ger => ドイツ語, chi => 中文

my $i = 1;
while (my $isbn = <>) {
    chomp $isbn;
    my $url = $top_url . $isbn . $tail_url;

    print STDERR $i, "\t", $url, "\n";

    my ($content, $error) = _access_web($url, TIMEOUT_MAX);
    if ($error) {
        die "http error $error \n";
    }
    print $i, "\t", $isbn, "\t";
    my $data = XMLin($content);

    if (ref $data->{'isbn'} eq 'ARRAY') {
        my @lang = grep { $_->{'lang'} eq LANG } @{$data->{'isbn'}};
        my @edit = sort { $b->{'year'} <=> $a->{'year'} } @lang;
        my $last = shift @edit;
        print $last->{'ed'}, "\t",
          $last->{'year'}, "\t",
          $last->{'content'}, "\t",
          $last->{'lang'};
    }
    print "\n";

    sleep(TIMEOUT_DEF);
    $i++;
}

sub disp_fields() {
   my $field = shift;
   my $item  = shift;
   print $item->{"$field"}, "\t"
      unless ref $item->{"$field"} eq "HASH";
}

# Webサーバへのアクセス
sub _access_web {
    my $url = shift;
    my $timeout = shift;
    my $usa = new LWP::UserAgent;
    my $request = new HTTP::Request('GET', $url);
    $usa->timeout([$timeout]);

    my $response = $usa->request($request);
    if ($response->code != RC_OK) {
        return (undef, $response->code);
    }
    else {
        return ($response->content, undef);
    }
}

__END__

Copyright  Maeda Akira (maeda@lib.u-tokyo.ac.jp)