Google Hacks 2Nd Edition [Electronic resources] نسخه متنی

Hack 92. Program Google in Perl

This simple script illustrates the basics of
programming the Google Web API with Perl and lays the groundwork for
the lion's share of hacks to come .

The vast majority of hacks in this book are written in Perl. While
the specifics vary from hack to hack, much of the busy work of
querying the Google API and looping over the results remain
essentially the same. This hack is utterly basic, providing a
foundation on which to build more complex and interesting
applications. If you haven't done anything of this
sort before, this hack is a good starting point for experimentation.
It simply submits a query to Google and prints out the results.

9.9.1. The Code

Type the following code into your preferred plain-text
editorbe it Notepad, TextEdit, or a command-line editor like
vi or Emacsand save it to a file named
googly.pl. Remember to replace
insert key here with your Google API key,
as explained in "Using Your Google API
Key" earlier in this chapter.

In addition to the Google API Developer's Kit, you'll need the SOAP::Lite Perl module installed [Hack #93] before running this hack.

#!/usr/local/bin/perl
# googly.pl
# A typical Google Web API Perl script.
# Usage: perl googly.pl <query>
# Your Google API developer's key.
my $google_key='insert key here';
# Location of the GoogleSearch WSDL file.
my $google_wdsl = "./GoogleSearch.wsdl";
use strict;
# Use the SOAP::Lite Perl module.
use SOAP::Lite;
# Take the query from the command line.
my $query = shift @ARGV or die "Usage: perl googly.pl <query>\n";
# Create a new SOAP::Lite instance, feeding it GoogleSearch.wsdl.
my $google_search = SOAP::Lite->service("file:$google_wdsl");
# Query Google.
my $results = $google_search ->
doGoogleSearch(
$google_key, $query, 0, 10, "false", ", "false",
", "latin1", "latin1"
);
# No results?
@{$results->{resultElements}} or exit;
# Loop through the results.
foreach my $result (@{$results->{resultElements}}) {
# Print out the main bits of each result
print
join "\n",
$result->{title} || "no title",
$result->{URL},
$result->{snippet} || 'no snippet',
"\n";
}

9.9.2. Running the Hack

Run this script from the command line ["How to Run
the Hacks" in the Preface], passing it any Google
search that you want to run like so:

$ perl googly.pl " query keywords "

9.9.3. The Results

Here's a sample run. The first attempt
doesn't specify a query and so triggers a usage
message and doesn't go any further. The second
searches for learning perl and prints out the
results.

% perl googly.pl
Usage: perl googly.pl <query>
% perl googly.pl " learning perl "
oreilly.com -- Online Catalog: Learning
Perl, 3rd Edition
http://www.oreilly.com/catalog/lperl3/
... learning perl, 3rd Edition Making Easy Things Easy and Hard Things
Possible By Randal L. Schwartz, Tom Phoenix 3rd Edition July
2001 0-596-00132-0
...
Amazon.com: buying info: learning perl (2nd Edition)
http://www.amazon.com/exec/obidos/ASIN/1565922840
... learning perl takes common programming idioms and expresses them
in "perlish"<br> terms. ... (learning perl,
Programming Perl, Perl Cookbook).