PHP：正则表达式搜索文件中的模式并将其拾取

Question

I am really confused with regular expressions for PHP.

Anyway, I cant read the whole tutorial thing now because I have a bunch of files in html which I have to find links in there ASAP. I came up with the idea to automate it with a php code which it is the language I know.

so I think I can user this script :

$address = "file.txt"; 
$input = @file_get_contents($address) or die("Could not access file: $address");
$regexp = "??????????"; 
if(preg_match_all("/$regexp/siU", $input, $matches)) { 
    // $matches[2] = array of link addresses 
   // $matches[3] = array of link text - including HTML code 
} 

My problem is with $regexp

My required pattern is like this:

href="/content/r807215r37l86637/fulltext.pdf" title="Download PDF

I want to search and get the /content/r807215r37l86637/fulltext.pdf from above lines which I have many of them in the files.

any help?

==================

edit

title attributes are important for me and all of them which I want, are titled

title="Download PDF"

Answer 1

Once again regexp are bad for parsing html.

Save your sanity and use the built in DOM libraries.

$dom = new DOMDocument();
@$dom->loadHTML($html);
$x = new DOMXPath($dom);
    $data = array();
foreach($x->query("//a[@title='Download PDF']") as $node)
{
    $data[] = $node->getAttribute("href");
}

Edit Updated code based on ircmaxell comment.