use strict;
use warnings;

use XML::XPath;
use XML::LibXML;
use WWW::Mechanize;
use HTTP::Cookies;

use Data::Dumper;
use constant URL => 'http://www.perlmonks.org';

my $user_name = ;
my $user_id   = ;
my $password  = ;
my $search    = 'onestary';
my $replace   = 'onastery';

my $agent       = login($user_name,$password);
my $raw_results = raw_search_results($agent,$user_name,$search);
my @link        = get_links($raw_results);

replace($agent,$_,$search,$replace) for @link;

sub replace {
   my ($agent,$link,$search,$replace) = @_;
   $agent->get(URL . $link);
   print STDERR "got $link ...";

   my $textarea = get_textarea($agent->{content});
   warn "no textarea for $link" and return unless $textarea;
   $textarea =~ s/$search/$replace/g;

   $agent->form(2);
   $agent->field('note_doctext',$textarea);
   $agent->click('sexisgood');
   print STDERR "done!\n";
}

sub get_textarea {
   my $html = shift;
   my $dom  = get_dom($html);
   my @node = $dom->findvalue(q|//textarea[@name='note_doctext']|);
   return $node[0];
}

sub get_links {
   my $html = shift;
   my $dom  = get_dom($html);
   my @link;
   for ($dom->findnodes(q|//table[@width='100%']/tr/td/a|)) {
      my $href = $_->getAttribute('href');
      next unless $href;
      my ($id) = $href =~ /(\d+)$/; $id ||= 0;
      push @link, $href if $id > $user_id;
   }
   return @link;
}

sub get_dom { XML::LibXML->new->parse_html_string(shift) }

sub raw_search_results {
   my ($agent,$author,$text) = @_;

   # Super Search is node 3989
   $agent->get(URL . '/index.pl?node_id=3989');
   $agent->form(2);
   $agent->field(@$_) for (
      ['BIT', $text],      # search text
      [qw(xa 0 1)],        # include ...
      ['a', $author],      # author
   ); 
   $agent->click('go');
   print STDERR "got search results ...\n";

   return $agent->{content};
}

sub login {
   my ($user,$pass) = @_;

   my $agent = WWW::Mechanize->new();
   $agent->cookie_jar(HTTP::Cookies->new());

   # Reviews is a fast loading page to login with
   $agent->get(URL . '/index.pl?node_id=21144');
   $agent->form(2);
   $agent->field(@$_) for (
      [qw(op login)],
      ['user', $user],
      ['passwd',$pass],
   );
   $agent->click('login');
   print STDERR "logged in ...\n";

   return $agent;
}
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