[wp-hackers] Extract first image from a post

[Alex Hempton-Smith]

Okay, after some searching I've managed to get it working with some very
complicated (for me anyway) code, it goes completely over my head but at
least it works!
For anybody who's interested:

function teaserimg()
{

   ob_start();

       the_content();

       $html = ob_get_contents();

   ob_end_clean();
   $output = preg_match_all('/<img.+src=[\'"]([^\'"]+)[\'"].*>/i', $html,
$matches, PREG_SET_ORDER);

   $p = $matches [0] [1];

   // maximum width is defined here
   $mw = '215';

   // maximum height is defined here
   $mh = '160';

   if(list($w,$h) = @getimagesize($p)) {
   foreach(array('w','h') as $v) { $m = "m{$v}";
       if(${$v} > ${$m} && ${$m}) { $o = ($v == 'w') ? 'h' : 'w';
       $r = ${$m} / ${$v}; ${$v} = ${$m}; ${$o} = ceil(${$o} * $r); } }
   return("<img src='{$p}' alt=' ' width='{$w}' height='{$h}' />"); }
}

-- Alex