Finds a substring between two strings.

kagg_get_between.php

<?php

/**
 * Finds a substring between two strings.
 *
 * @param  string $string The string to be searched
 * @param  string $start The start of the desired substring
 * @param  string $end The end of the desired substring
 * @param  bool $greedy Use last instance of`$end` (default: false)
 *
 * @return string
 */
function kagg_get_between( $string, $start, $end, $greedy = false ) {
	$start = preg_quote( $start, '/' );
	$end   = preg_quote( $end, '/' );

	$format = '/(%s)(.*';
	if ( ! $greedy ) {
		$format .= '?';
	}
	$format .= ')(%s)/';

	$pattern = sprintf( $format, $start, $end );
	preg_match( $pattern, $string, $matches );

	return $matches[2];
}