[paulOr]

A really great little way to see how well your site interacts with Google, is to find out how often / much googlebot visits your website, I made this little bit of code so that i could just that!

SQL Database

CODE

CREATE TABLE `googlebot` (
  `counter` int(20) NOT NULL
) ENGINE=MyISAM DEFAULT CHARSET=latin1;

Source Code

CODE

<?php
    if( eregi("googlebot", $_SERVER['HTTP_USER_AGENT']) ) {
        mysql_query("UPDATE `googlebot` SET counter = counter + 1");
    }

    $count = mysql_fetch_row(mysql_query("SELECT `counter` FROM googlebot"));

    print $count[0]." GoogleBot visits.";
?>

More @ paulOr.net

[Bob]

I believe you can get even more detailed statistics about how google crawlers interact with your site (crawling errors, index stats, amount of pages crawler per day, bandwidth usage, etc) with google's webmaster tools (http://www.google.com/webmasters/tools/)

[webtuto]

Here is a simple way of checking if the visitor if your page is a search engine or a normal person. It does this by checking if the user agent returned by $_SERVER['HTTP_USER_AGENT'] contains one of the keywords search engine's user agents usually contain.

CODE

<?php

    //check if user is a bot of some sort
function is_bot()
{
    $bots = array('google','yahoo','msn');
    //takes the list above and returns (google)|(yahoo)|(msn)
    $regex = '('.implode($bots, ')|(').')';
    /*uses the generated regex above to see if those keywords are contained in the user agent variable*/    
    return eregi($regex, $_SERVER['HTTP_USER_AGENT']);
}

?>