I needed php’s mb_strrchr function, which is only in php 5.2+. However, my workplace is stuck in php 5.1 and cannot upgrade to php 5.2.

I decided to write a forwards-compatible mb_strrchr() that worked in php 5.1 at least. Please test thoroughly before using. It seemed to work great for the cases I needed it for:

// php 5.1 compat
if( !function_exists('mb_strrchr') ) {
	function mb_strrchr( $haystack, $needle, $part = false, $encoding = '' ) {
		
		$pos = mb_strrpos( $haystack, $needle, $encoding );
		if( $pos === false ) return false;
		
		if( $part === true ) {
			return mb_strcut( $haystack, 0, $pos, $encoding );
		} else {
			return mb_strcut( $haystack, $pos, mb_strlen($haystack), $encoding );
		}
	}
}