如何从页面获取所有网址(php)

Question

我有一个页面,其中包含一个在另一个下面列出的描述(类似于书签/网站列表).如何使用php从该页面获取所有网址并将其写入txt文件(每行一个,只有网址没有说明)？

页面看起来像这样:

一些描述

其他描述

另一个

我希望脚本的txt输出看起来像这样:

http://link.com

http://link2.com

http://link3.com

Answer 1

单程

$url="http://wwww.somewhere.com";
$data=file_get_contents($url);
$data = strip_tags($data,"<a>");
$d = preg_split("/<\/a>/",$data);
foreach ( $d as $k=>$u ){
    if( strpos($u, "<a href=") !== FALSE ){
        $u = preg_replace("/.*<a\s+href=\"/sm","",$u);
        $u = preg_replace("/\".*/","",$u);
        print $u."\n";
    }
}

Answer 2

其他方式

$url = "http://wwww.somewhere.com";

$html = file_get_contents($url);

$doc = new DOMDocument();
$doc->loadHTML($html); //helps if html is well formed and has proper use of html entities!

$xpath = new DOMXpath($doc);

$nodes = $xpath->query('//a');

foreach($nodes as $node) {
    var_dump($node->getAttribute('href'));
}

Answer 3

您可以使用它来获取给定网页中的所有链接。

<?php

    $var = fread_url($url);

    preg_match_all ("/a[\s]+[^>]*?href[\s]?=[\s\"\']+".
                    "(.*?)[\"\']+.*?>"."([^<]+|.*?)?<\/a>/", 
                    $var, &$matches);

    $matches = $matches[1];
    $list = array();

    foreach($matches as $var)
    {    
        print($var."<br>");
    }

    function fread_url($url,$ref="")
    {
        if(function_exists("curl_init")){
            $ch = curl_init();
            $user_agent = "Mozilla/4.0 (compatible; MSIE 5.01; ".
                          "Windows NT 5.0)";
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_USERAGENT, $user_agent);
            curl_setopt( $ch, CURLOPT_HTTPGET, 1 );
            curl_setopt( $ch, CURLOPT_RETURNTRANSFER, 1 );
            curl_setopt( $ch, CURLOPT_FOLLOWLOCATION , 1 );
            curl_setopt( $ch, CURLOPT_FOLLOWLOCATION , 1 );
            curl_setopt( $ch, CURLOPT_URL, $url );
            curl_setopt( $ch, CURLOPT_REFERER, $ref );
            curl_setopt ($ch, CURLOPT_COOKIEJAR, 'cookie.txt');
            $html = curl_exec($ch);
            curl_close($ch);
        }
       else{
            $hfile = fopen($url,"r");
            if($hfile){
                while(!feof($hfile)){
                    $html.=fgets($hfile,1024);
                }
            }
        }
        return $html;
    }

    ?>