How to get html tag from string in php?

I have a html output I'm pulling from a RSS feed, it is somethig like this:

<div>
    <p>
        Some text
    </p>
    <iframe src="http://www.source.com"></iframe>
</div>

The problem is that I only开发者_如何学Python need the attr "src" of the iframe tag, Is there a way to get it with PHP? Regex maybe?

Thanks in advance!

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If you're consistently getting just the data you listed above, you could use a simple substring, using the string positions of src=" and "><iframe to specify which substring you want:

$html = '<div><p>Some text</p><iframe src="http://www.source.com"></iframe></div>';

$start = strpos($html, 'src="') + 5;
$length = strpos($html, '"></iframe') - $start;
$src = substr($html, $start, $length);

echo $src;

EDIT - fixed the code and split into multiple lines. This could easily be a one-liner, but - thought it was easier to understand if I broke into multiple lines.

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I'd recommend DOMDocument or SimpleXML.

Something like this might give you the idea.

var_dump(simplexml_load_string($rss_feed));

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I'm not an expert with regex, but a alternative way would be to use explode on the " marks and get array[1] like this:

$rssFeed = '<div>
    <p>
        Some text
    </p>
    <iframe src="http://www.source.com"></iframe>
</div>';

$rssArray = explode('"', $rssFeed);

echo $rssArray[1];

This requires your RSS feed to be very consistent though, if the "Some text" part were to contain " marks, this would mess up and you'd get a wrong string.

You could look through the array for everything starting with http or www to work around errors, but again, it requires a very consistent RSS feed, so you have to judge for you self if this would do the job good enough.

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You could parse this output with a little command line perl script. This can be quite robust depending on how general you make the regular expression.

For example,

$command = "echo your_html_output | perl -pe 's/src=\"(.*)\"/$1/'"; # Capture what is in between src=" and the " (the closing quote)

$output = shell_exec("$command");