(PHP 4 >= 4.2.0, PHP 5, PHP 7) Setup string and regular expression for a multibyte regular expression match

(PHP 5 >= 5.4.1, PHP 7) Perform a regular expresssion seach and replace with multibyte support using a callback

(PHP 4 >= 4.0.6, PHP 5, PHP 7) Find position of last occurrence of a string in a string

(PHP 4 >= 4.0.6, PHP 5, PHP 7) Detect HTTP input character encoding

(PHP 4 >= 4.0.6, PHP 5, PHP 7) Get part of string