Question

I have a string, with a htmlentities encoded HTML code.

What I want to do is find all the paths in the document, between:

href=”XXX”, src=”XXX”.

I do have a regex expression that find all the links starting by http, https, ftp and file, and lest me iterate over it:

"/\b(?:(?:https?|ftp|file):\/\/|www\.|ftp\.)[-A-Z0-9+&@#\/%=~_|$?!:,.]*[A-Z0-9+&@#\/%=~_|$]/i"

Any idea?

Answer 1

Update: Doing it with a regex isn’t reliable. The src=”..” or href=”..” statement can be part of a comment or a javascript statement. To reliable obtain the links I would suggest to use XPath:

<?php

$html = file_get_contents('http://stackoverflow.com/questions/14782334/regex-expression-to-find-all-paths-in-a-html-string/14782594#14782594');
$doc = new DOMDocument();
@$doc->loadHTML($html);
$selector = new DOMXPath($doc);

$result = $selector->query('//a/@href | //@src');
foreach($result as $link) {
    echo $link->value, PHP_EOL;
}

---

If using a regex I would try to grab the content between the = " of the href or src attribute. Here comes an example how to get the links from this page using a regex:

<?php

$html = file_get_contents('http://stackoverflow.com/questions/14782334/regex-expression-to-find-all-paths-in-a-html-string');

preg_match_all('/href="(?P<href>.*)"|src="(?P<src>.*)"/U', $html, $m);
                                                        <--- note the U to make the 
                                                             pattern ungreedy
var_dump($m['href']);
var_dump($m['src']);