_CP_sort is equivalent to the result = sort(string) BASIC statement.
int _CP_sort(CPSTR** result, CPSTR* string)
This function returns -1 if an error occurs. The error code is contained in _CP_errno.
/* Prints "a^b". */
CPSTR * s = _CP_mkstr("b\376a");
_CP_sort(&s,s);
_CP_print(s);