PHP学习：利用php抓取蜘蛛爬虫痕迹的示例代码

PHP实战
<?php
//获取蜘蛛爬虫名或防采集
function isSpider(){
  $bots = array(
          'Google'  => 'googlebot',
          'Baidu'    => 'baiduspider',
          'Yahoo'    => 'yahoo slurp',
          'Soso'    => 'sosospider',
          'Msn'    => 'msnbot',
          'Altavista'  => 'scooter ',
          'Sogou'    => 'sogou spider',
          'Yodao'    => 'yodaobot'
      );
  $userAgent = strtolower($_SERVER['HTTP_USER_AGENT']);
  foreach ($bots as $k => $v){
    if (strstr($v,$userAgent)){
      return $k;
      break;
    }
  }
  return false;
} 
//获取哪种蜘蛛爬虫后保存蜘蛛痕迹.
//根据采集时HTTP_USER_AGENT是否为空来防止采集
//抓蜘蛛爬虫
$spi  = isSpider();
if($spi){
  $tlc_thispage  = addslashes($_SERVER['HTTP_USER_AGENT']);
  $file      = 'robot.txt';
  $time      = date('Y-m-d H:i:s',mktime());
  $handle      = fopen($file,'a+');
  $PR        = $_SERVER['REQUEST_URI'];
  fwrite($handle, "Time:{$time} ROBOT:{$spi} AGENT:{$tlc_thispage} URL:{$PR} \n\r");
  fclose($handle);
}
?>