PHP多线程抓取网页实现代码

<?php
$urls = array(
'http://www.sina.com.cn/',
'http://www.sohu.com/',
'http://www.163.com/'
); // 设置要抓取的页面URL

$save_to='/test.txt'; // 把抓取的代码写入该文件

$st = fopen($save_to,"a");
$mh = curl_multi_init();

foreach ($urls as $i => $url) {
$conn[$i] = curl_init($url);
curl_setopt($conn[$i], CURLOPT_USERAGENT, "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)");
curl_setopt($conn[$i], CURLOPT_HEADER ,0);
curl_setopt($conn[$i], CURLOPT_CONNECTTIMEOUT,60);
curl_setopt($conn[$i], CURLOPT_FILE,$st); // 设置将爬取的代码写入文件
curl_multi_add_handle ($mh,$conn[$i]);
} // 初始化

do {
curl_multi_exec($mh,$active);
} while ($active); // 执行

foreach ($urls as $i => $url) {
curl_multi_remove_handle($mh,$conn[$i]);
curl_close($conn[$i]);
} // 结束清理

curl_multi_close($mh);
fclose($st);
?>

<?php
$urls = array(
'http://www.sina.com.cn/',
'http://www.sohu.com/',
'http://www.163.com/'
);

$save_to='/test.txt'; // 把抓取的代码写入该文件
$st = fopen($save_to,"a");

$mh = curl_multi_init();
foreach ($urls as $i => $url) {
$conn[$i] = curl_init($url);
curl_setopt($conn[$i], CURLOPT_USERAGENT, "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)");
curl_setopt($conn[$i], CURLOPT_HEADER ,0);
curl_setopt($conn[$i], CURLOPT_CONNECTTIMEOUT,60);
curl_setopt($conn[$i],CURLOPT_RETURNTRANSFER,true); // 设置不将爬取代码写到浏览器，而是转化为字符串
curl_multi_add_handle ($mh,$conn[$i]);
}

do {
curl_multi_exec($mh,$active);
} while ($active);

foreach ($urls as $i => $url) {
$data = curl_multi_getcontent($conn[$i]); // 获得爬取的代码字符串
fwrite($st,$data); // 将字符串写入文件。当然，也可以不写入文件，比如存入数据库
} // 获得数据变量，并写入文件

foreach ($urls as $i => $url) {
curl_multi_remove_handle($mh,$conn[$i]);
curl_close($conn[$i]);
}

curl_multi_close($mh);
fclose($st);
?>