Grab first link from post for external link

Assuming you mean the Link Post Format, then yes – you can output the post in any way that you like. Have a look at Twenty Eleven theme for a way of handling this – specifically the content-link.php and index.php files.

Thanks esmi.

I see the relevant code in functions.php is this:

function twentyeleven_url_grabber() {
	if ( ! preg_match( '/<a\s[^>]*?href=[\'"](.+?)[\'"]/is', get_the_content(), $matches ) )
		return false;

	return esc_url_raw( $matches[1] );
}

Is it possible to pull this off without creating a separate content-link.php though?

In theory, you could use a conditional based on get_post_format() to code up different loop displays, yes.

Yes, but what do I want to display? Both the content.php and content-link.php link to the permalink in the title.

what do I want to display?

Err… that’s up to you. If you do not want the post’s title to be a permalink to the single post view, don’t make it a link.

The post title should point to the external link, so I suppose my question is: how do I reference that external link which I’ve just “grabbed”?

There might be prettier ways of doing this but I’ve used the following in one of my themes:

<?php
// Get the text & url from the first link in the content
$content = get_the_content();
$link_string = my_extract_from_string('<a href=', '/a>', $content);
$link_bits = explode('"', $link_string);
foreach( $link_bits as $bit ) {
	if( substr($bit, 0, 1) == '>') $link_text = substr($bit, 1, strlen($bit)-2);
	if( substr($bit, 0, 4) == 'http') $link_url = $bit;
}?>
<h2 class="post-title"><a href="<?php echo $link_url;?>" title="<?php _e('External link';?>"><?php echo $link_text;?></a></h2>

And the function:

// Extract first occurance of text from a string
function my_extract_from_string($start, $end, $tring) {
	$tring = stristr($tring, $start);
	$trimmed = stristr($tring, $end);
	return substr($tring, strlen($start), -strlen($trimmed));
}

Ok, added that to function and tried this is in content.php:

<?php if ( has_post_format( 'link' )) {
$content = get_the_content();
$link_string = my_extract_from_string('<a href=', '/a>', $content);
$link_bits = explode('"', $link_string);
foreach( $link_bits as $bit ) {
	if( substr($bit, 0, 1) == '>') $link_text = substr($bit, 1, strlen($bit)-2);
	if( substr($bit, 0, 4) == 'http') $link_url = $bit;
}?>
<h1 class="entry-title"><a href="<?php echo $link_url;?>" title="<?php _e('External link';?>"><?php echo $link_text;?></a></h1><?php }
else {
?>

		<h1 class="entry-title"><a href="<?php the_permalink(); ?>" title="<?php printf( esc_attr__( 'Permalink to %s', 'toolbox' ), the_title_attribute( 'echo=0' ) ); ?>" rel="bookmark"><?php the_title(); ?></a></h1>
<?php } ?>

But it doesn’t work. I must have done something wrong there with the code because the page won’t even load….