foreach within for each (preg match url, and imgurl)

Question

我在一个变量（$data）中有 html 并找到 URL，我称之为 $url 和 imgurl，

但我不知道如何为每个项目也找到 URL（它最终会回显所有匹配项，而不是每个匹配项）。

我正在尝试学习一般的解决方案，假设您有一个 html 页面，您想要提取 img src 和 href src 并为每个页面回显它们...

$data = "75http://upload.wikimedia.org/wikipedia/commons/7/7a/Britney_Spears_2013.jpgimgrefurlhttp://en.wikipedia.org/wiki/Britney_Spears\?imgurlhttp://www.spirituelquotes.com/wp-content/uploads/2014/12/britney-spears.jpgimgrefurlhttp://www.spirituelquotes.com/celebrities/britney-spears/";


//finds url; (below is code rough to give an idea ) 
 preg_match_all("/ru=\'(.*?)\'\;/is", $data, $matches); 
matches = $url;

 //finds imgurl
 preg_match_all("/imgurl%5C75(.*?)%5C/is", $data, $matches); 

 matches = $img;

 foreach $maches(){
 echo $url $img;  
 //whatever else you want to do
 }


output would be:

http://www.example.com http://www.example.com/image.jpg

http://www.example.com/dir/name2 http://www.example.com/image2.jpg

http://www.example.com/dir/name3 http://www.example.com/image3.jpg

http://www.example.com/dir/name3 http://www.example.com/image4.jpg

或：

$data = getfile contents(http://example.com)  

//finds url;
preg_match_all("/ru=\'(.*?)\'\;/is", $data, $matches); 
matches = $url

//finds the img url
 preg_match_all("/imgurl%5C75(.*?)%5C/is", $data, $matches); 

foreach($matches[1] as $imgurl){
 echo $imgurl $url and (basically want to echo url for each matches in foreach command)


 }

此代码有效，但我只想在 for each:

中添加 url

preg_match_all("/ru=\'(.*?)\'\;/is", $data, $matches); 
foreach($matches[1] as $url)


preg_match_all("/imgurl%5C75(.*?)%5C/is", $data, $matches); 
foreach($matches[1] as $imgurl){
$filename = basename($imgurl);

    echo $imgurl; //works
    echo $url; //displays all $urls found

$img = "$filename";

error_reporting(E_ALL);

$ch = curl_init(); 
$timeout = 0; 
curl_setopt ($ch, CURLOPT_URL, $imgurl); 
curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT, $timeout); 

curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); 
curl_setopt($ch, CURLOPT_BINARYTRANSFER, 1); 

$image = curl_exec($ch); 
curl_close($ch); 

$f = fopen($img, 'w');
fwrite($f, $image);
fclose($f);


}

}
}

Answer 1

尝试用正则表达式解析像 HTML 这样复杂的东西总是一个坏主意。您应该为这样的工作使用解析器。

<?php

// Suppress errors on unknown elements.
libxml_use_internal_errors(true);

// Create a new libxml2 DOM document instance.
$domDocument = new \DOMDocument();

// Parse the HTML string.
$domDocument->loadHTML("<a href=http://www.example.com/dir/name><img src=http://www.example.com/image.jpg></a><a href=http://www.example.com/dir/name2><img src=http://www.example.com/image2.jpg></a><a href=http://www.example.com/dir/name3><img src=http://www.example.com/image3.jpg></a><a href=http://www.example.com/dir/name4><img src=http://www.example.com/image4.jpg></a>");

// Go through all DOM elements we are interested in.
foreach (array("a" => "href", "img" => "src") as $tagName => $attribute) {
    foreach ($domDocument->getElementsByTagName($tagName) as $domElement) {
        // Make sure the element has the desired attribute.
        if ($domElement->hasAttribute($attribute)) {
            echo $domElement->getAttribute($attribute) , PHP_EOL;
        }
    }
}

请注意，如果您尝试解析包含一些新元素的 HTML5 文档，libxml2 可能会抛出错误。您可以使用 libxml_use_internal_errors.

解决此问题

---

如果你坚持使用正则表达式或者你只是想学习正则表达式（查看regx101.com[无从属关系]学习正则表达式）那么解决方案是：

<?php

$data = "<a href=http://www.example.com/dir/name><img src=http://www.example.com/image.jpg></a><a href=http://www.example.com/dir/name2><img src=http://www.example.com/image2.jpg></a><a href=http://www.example.com/dir/name3><img src=http://www.example.com/image3.jpg></a><a href=http://www.example.com/dir/name4><img src=http://www.example.com/image4.jpg></a>";

preg_match_all("/(?:href|src)=(?:\"|')?([^\"'> ]*)(?:\"|'| |>)/", $data, $matches);

var_dump($matches);

/* OUTPUT:
array(2) {
  [0]=>
  array(8) {
    [0]=>
    string(37) "href=http://www.example.com/dir/name>"
    [1]=>
    string(37) "src=http://www.example.com/image.jpg>"
    [2]=>
    string(38) "href=http://www.example.com/dir/name2>"
    [3]=>
    string(38) "src=http://www.example.com/image2.jpg>"
    [4]=>
    string(38) "href=http://www.example.com/dir/name3>"
    [5]=>
    string(38) "src=http://www.example.com/image3.jpg>"
    [6]=>
    string(38) "href=http://www.example.com/dir/name4>"
    [7]=>
    string(38) "src=http://www.example.com/image4.jpg>"
  }
  [1]=>
  array(8) {
    [0]=>
    string(31) "http://www.example.com/dir/name"
    [1]=>
    string(32) "http://www.example.com/image.jpg"
    [2]=>
    string(32) "http://www.example.com/dir/name2"
    [3]=>
    string(33) "http://www.example.com/image2.jpg"
    [4]=>
    string(32) "http://www.example.com/dir/name3"
    [5]=>
    string(33) "http://www.example.com/image3.jpg"
    [6]=>
    string(32) "http://www.example.com/dir/name4"
    [7]=>
    string(33) "http://www.example.com/image4.jpg"
  }
}
*/