no locale : ABCDEFGHIJKLabcdefghijkl
POSIX     : ABCDEFGHIJKLabcdefghijkl
use locale: aAbBcCdDeEfFgGhHiIjJkKlL
no locale : Laa aaa aab aba abb lab 
POSIX     : Laa aaa aab aba abb lab 
use locale: aba abb lab Laa aaa aab