index_option Function

  elemental function index_option(self, back, section_name, option_name) result(ind)
  !< Return the index of the option (inside a  section) matching the name(s) passed.
  !<
  !< @note The matching index returned is the first found if *back* is not passed or if *back=.false.*. On the contrary the last
  !< found is returned if *back=.true.*.
  class(file_ini),   intent(in) :: self         !< File data.
  logical, optional, intent(in) :: back         !< If back appears with the value true, the last matching index is returned.
  character(*),      intent(in) :: option_name  !< Option  name.
  character(*),      intent(in) :: section_name !< Section name.
  integer(I4P)                  :: ind          !< Index of searched section.
  logical                       :: backd        !< Dummy back flag.
  integer(I4P)                  :: s            !< Counter.

  ind = 0
  if (allocated(self%sections)) then
    backd = .false. ; if (present(back)) backd = back
    s = self%index(section_name=section_name, back=backd)
    if (s>0) then
      ind = self%sections(s)%index(option_name=option_name, back=backd)
    endif
  endif
  endfunction index_option