php获取从百度搜索进入网站的关键词的详细代码

<?php 
function search_word_from() { 
$referer = isset($_SERVER['HTTP_REFERER'])?$_SERVER['HTTP_REFERER']:''; 
if(strstr( $referer, 'baidu.com')){ //百度 
preg_match( "|baidu.+wo?r?d=([^\&]*)|is", $referer, $tmp ); 
$keyword = urldecode( $tmp[1] ); 
$from = 'baidu';  
}elseif(strstr( $referer, 'google.com') or strstr( $referer, 'google.cn')){ //谷歌 
preg_match( "|google.+q=([^\&]*)|is", $referer, $tmp ); 
$keyword = urldecode( $tmp[1] ); 
$from = 'google'; 
}elseif(strstr( $referer, 'so.com')){ //360搜索 
preg_match( "|so.+q=([^\&]*)|is", $referer, $tmp ); 
$keyword = urldecode( $tmp[1] ); 
$from = '360'; 
}elseif(strstr( $referer, 'sogou.com')){ //搜狗 
preg_match( "|sogou.com.+query=([^\&]*)|is", $referer, $tmp ); 
$keyword = urldecode( $tmp[1] ); 
$from = 'sogou'; 
}elseif(strstr( $referer, 'soso.com')){ //搜搜 
preg_match( "|soso.com.+w=([^\&]*)|is", $referer, $tmp ); 
$keyword = urldecode( $tmp[1] ); 
$from = 'soso'; 
}else { 
$keyword =''; 
$from = ''; 
} 

return array('keyword'=>$keyword,'from'=>$from); 
} 

//以下为测试 
//在搜索引擎搜索个关键词，进入网站 
$word = search_word_from(); 
if(!empty($word['keyword'])){ 
echo '关键字：'.$word['keyword'].' 来自：'.$word['from']; 
} 
?>