Just a Crawler

use strict;
use WWW::Mechanize;
use HTTP::Cookies;

###go to login page and login.
#my $url = 'https://www.google.com/accounts/ServiceLogin?hl=en&service=finance&nui=1&continue=http%3A%2F%2Ffinance.google.com%2Ffinance';
my $url = 'https://accounts.google.com/ServiceLogin';
my $username = $ARGV[0];
my $password = $ARGV[1];
my $keyword = $ARGV[2];
my $outputfile = $ARGV[3];
chomp($username);
chomp($password);
chomp($keyword);
chomp($outputfile);

print "usr: $username\n";
print "psw: $password\n";
print "keyword: $keyword\n";
print "output: $outputfile\n";
print "Searching ......\n";

my $mech = WWW::Mechanize->new();
$mech->cookie_jar(HTTP::Cookies->new());
$mech->get($url);
$mech->form_number(1);
$mech->field(Email => $username);
$mech->field(Passwd => $password);
$mech->click();
#Go to the next link, now that we are logged in.
#$url = 'http://www.google.com/trends/viz?q=alan+kay&graph=all_csv&sa=N';
$url = 'http://www.google.com/trends/viz?q='.$keyword.'&date=all&geo=cn&graph=all_csv&scale=1&sa=N';
#$url = 'http://finance.google.com/finance/portfolio?action=view&pid=1&pview=pview&output=csv';

$mech->get($url);
my $output_page = $mech->content();

my $fh;
open $fh, ">$outputfile";
print $fh $output_page;

12/4/2011 Update

This script  can't work sometimes because of  Google 's ban.