返回结果为1为收录，为0则没有收录。

function checkBaidu($url){
    $url = 'http://www.baidu.com/s?wd='.$url;
    $curl = curl_init();
    curl_setopt($curl, CURLOPT_URL, $url);
    curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
    $rs = curl_exec($curl);
    curl_close($curl);
    $arr = parse_url($url);
          
    if (strpos($arr['query'], 'http://')) {
        $arr['query'] = str_replace('http://', '', str_replace('wd=', '', $arr['query']));
    }else{
        $arr['query'] = str_replace('wd=', '', $arr['query']);
    } 
    if(strpos($arr['query'], '?')){
        $str = strstr($arr['query'], '?');
        $arr['query'] = str_replace($str, '', $arr['query']);
    }
          
    if (strpos($arr['query'], '/')) {
        $narr = explode('/', $arr['query']);
        $arr['query'] = $narr[0];
    }
          
    if (strpos($rs, ''.$arr['query'].'')) {
        return 1;
    }else{
        return 0;
    }
}
echo checkBaidu('http://www.youkud.com/content.php?id=910');