php结合curl实现多线程抓取
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2023-09-06 12:09:25
php结合curl实现多线程抓取
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($data);//输出 //如果post的数据大于1024字节,curl并不会直接就发起post请求 //发送请求时,header中包含一个空的expect。curl_setopt($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( '//www.jb51.net/', '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( '//www.jb51.net/', '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( '//www.jb51.net/5w.zip', '//www.jb51.net/5w.zip', '//www.jb51.net/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( '//www.jb51.net/5w.zip', '//www.jb51.net/5w.zip', '//www.jb51.net/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);
以上所述就是本文的全部内容了,希望大家能够喜欢。
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