php 结合 curl 实现多线程抓取
- <?php
- /*
- curl 多线程抓取
- */
- /**
- * curl 多线程
- *
- * @param array $array 并行网址
- * @param int $timeout 超时时间
- * @return array
- */
- function Curl_http($array,$timeout){
- $res = array();
- $mh = curl_multi_init();// 创建多个 curl 语柄
- $startime = getmicrotime();
- foreach($array as $k=>$url){
- $conn[$k]=curl_init($url);
- curl_setopt($conn[$k], CURLOPT_TIMEOUT, $timeout);// 设置超时时间
- curl_setopt($conn[$k], CURLOPT_USERAGENT, 'Mozilla/5.0 (compatible; MSIE 5.01; Windows NT 5.0)');
- curl_setopt($conn[$k], CURLOPT_MAXREDIRS, 7);//HTTp 定向级别
- curl_setopt($conn[$k], CURLOPT_HEADER, 0);// 这里不要 header, 加块效率
- curl_setopt($conn[$k], CURLOPT_FOLLOWLOCATION, 1); // 302 redirect
- curl_setopt($conn[$k],CURLOPT_RETURNTRANSFER,1);
- curl_multi_add_handle ($mh,$conn[$k]);
- }
- // 防止死循环耗死 cpu 这段是根据网上的写法
- do {
- $mrc = curl_multi_exec($mh,$active);// 当无数据, active=true
- } while ($mrc == CURLM_CALL_MULTI_PERFORM);// 当正在接受数据时
- while ($active and $mrc == CURLM_OK) {// 当无数据时或请求暂停时, active=true
- if (curl_multi_select($mh) != -1) {
- do {
- $mrc = curl_multi_exec($mh, $active);
- } while ($mrc == CURLM_CALL_MULTI_PERFORM);
- }
- }
- foreach ($array as $k => $url) {
- curl_error($conn[$k]);
- $res[$k]=curl_multi_getcontent($conn[$k]);// 获得返回信息
- $header[$k]=curl_getinfo($conn[$k]);// 返回头信息
- curl_close($conn[$k]);// 关闭语柄
- curl_multi_remove_handle($mh , $conn[$k]); // 释放资源
- }
- curl_multi_close($mh);
- $endtime = getmicrotime();
- $diff_time = $endtime - $startime;
- return array('diff_time'=>$diff_time,
- 'return'=>$res,
- 'header'=>$header
- );
- }
- // 计算当前时间
- function getmicrotime() {
- list($usec, $sec) = explode(" ",microtime());
- return ((float)$usec + (float)$sec);
- }
- // 测试一下, curl 三个网址
- $array = array(
- "http://www.weibo.com/",
- "http://www.renren.com/",
- "http://www.qq.com/"
- );
- $data = Curl_http($array,'10');// 调用
- var_dump($data);// 输出
- // 如果 POST 的数据大于 1024 字节, curl 并不会直接就发起 POST 请求
- // 发送请求时, header 中包含一个空的 Expectcurl_setopt($ch, CURLOPT_HTTPHEADER, array("Expect:"));
- ?>
我们再来看几个例子
(1) 下面这段代码是实现抓取多个 URL, 然后将抓取的 URL 的页面代码写入指定的文件
- $urls = array(
- 'http://www.bitsCN.com/',
- 'http://www.google.com/',
- 'http://www.example.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); // 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);
(2) 下面这段代码和上面差不多意思, 只不过这个地方是将获得的代码先放入变量, 然后再将获取到的内容写入指定的文件
- $urls = array(
- 'http://www.bitsCN.com/',
- 'http://www.google.com/',
- 'http://www.example.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[$i],CURLOPT_RETURNTRANSFER,true); // 不将爬取代码写到浏览器, 而是转化为字符串
- curl_multi_add_handle ($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,$data); // 将字符串写入文件
- } // 获得数据变量, 并写入文件
- foreach ($urls as $i => $url) {
- curl_multi_remove_handle($mh,$conn[$i]);
- curl_close($conn[$i]);
- }
- curl_multi_close($mh);
- fclose($st);
(3) 下面这段代码实现的是利用 PHP 的 Curl Functions 实现并发多线程下载文件
- $urls=array(
- 'http://www.bitsCN.com/5w.zip',
- 'http://www.bitsCN.com/5w.zip',
- 'http://www.bitsCN.com/5w.zip'
- );
- $save_to='./home/';
- $mh=curl_multi_init();
- foreach($urls as $i=>$url){
- $g=$save_to.basename($url);
- if(!is_file($g)){
- $conn[$i]=curl_init($url);
- $fp[$i]=fopen($g,"w");
- curl_setopt($conn[$i],CURLOPT_USERAGENT,"Mozilla/4.0(compatible; MSIE 7.0; Windows NT 6.0)");
- curl_setopt($conn[$i],CURLOPT_FILE,$fp[$i]);
- curl_setopt($conn[$i],CURLOPT_HEADER ,0);
- curl_setopt($conn[$i],CURLOPT_CONNECTTIMEOUT,60);
- curl_multi_add_handle($mh,$conn[$i]);
- }
- }
- do{
- $n=curl_multi_exec($mh,$active);
- }while($active);
- foreach($urls as $i=>$url){
- curl_multi_remove_handle($mh,$conn[$i]);
- curl_close($conn[$i]);
- fclose($fp[$i]);
- }
- curl_multi_close($mh);$urls=array(
- 'http://www.bitsCN.com/5w.zip',
- 'http://www.bitsCN.com/5w.zip',
- 'http://www.bitsCN.com/5w.zip'
- );
- $save_to='./home/';
- $mh=curl_multi_init();
- foreach($urls as $i=>$url){
- $g=$save_to.basename($url);
- if(!is_file($g)){
- $conn[$i]=curl_init($url);
- $fp[$i]=fopen($g,"w");
- curl_setopt($conn[$i],CURLOPT_USERAGENT,"Mozilla/4.0(compatible; MSIE 7.0; Windows NT 6.0)");
- curl_setopt($conn[$i],CURLOPT_FILE,$fp[$i]);
- curl_setopt($conn[$i],CURLOPT_HEADER ,0);
- curl_setopt($conn[$i],CURLOPT_CONNECTTIMEOUT,60);
- curl_multi_add_handle($mh,$conn[$i]);
- }
- }
- do{
- $n=curl_multi_exec($mh,$active);
- }while($active);
- foreach($urls as $i=>$url){
- curl_multi_remove_handle($mh,$conn[$i]);
- curl_close($conn[$i]);
- fclose($fp[$i]);
- }
- curl_multi_close($mh);
来源: https://www.php1.cn/detail/php-47719e9a9a.html