using a readfile() value as a variable

[ginerjm]

Ok - think I got it.  This relies on always finding a period at the end of every sentence.

$contents = "This is where cat is found.  And it may be where cat is found a second time.  And here it is the third occurrence of cat.  Following the 3rd cat we have the 4th cat right here.";
$sch_str = 'cat';

echo "Contents are:<br><br>";
echo "$contents<br><br>";
$last_start = 0;
$last_end = 0;
while ($pos = stripos($contents, $sch_str))
{
	// we have found the pos of the desired string
	// now locate the . prior to that pos
	$start = strrpos(substr($contents, 0, $pos), '.');
	if (!$start)
		$start = 0;
	// now find the . following the current pos
	$end = stripos(substr($contents, $pos), '.') + $pos +1;
	// now output the sentence using start and end pos's
	echo "start $last_start, end " . 
			($last_end + $end) . " : " . 
			substr($contents, $start, $end) . 
			'<br>';
	$contents = substr($contents, $end + 1);
	$last_start = $last_start + $end +1;
	$last_end = $last_end + $end +1;
}