Returns the length of a character string, ignoring any trailing blanks.
Fortran 95 and later, with kind argument Fortran 2003 and later
result = len_trim(string [, kind])
string - Shall be a scalar of type character, with intent(in)kind - (Optional) An integer initialization expression indicating the kind parameter of the result.The return value is of type integer and of kind kind. If kind is absent, the return value is of default integer kind.