This is a simple PHP function which can fetch data between two tags/delimiters. Which is helpful if in case you want to crawl site for specific content.

<?php  
  function fetch_data($string, $start_tag, $end_tag){
  
        $position = stripos($string, $start_tag);  
		
	$str = substr($string, $position);  
		
	$str_second = substr($str, strlen($start_tag));  
		
	$second_positon = stripos($str_second, $end_tag);  
		
	$str_third = substr($str_second, 0, $second_positon);  
		
	$fetch_data = trim($str_third);
		
	return $fetch_data; 
  }

?>

Example is:

<?php

$string = 'I prefer PHP for web development';
$fetch_data = fetch_data($string, 'prefer', 'for');
echo $fetch_data;
//OUTPUT: PHP

?>