pop_char Function

  recursive character function pop_char(unit, eof, skip_ws) result(popped)
    integer, intent(in) :: unit
    logical, intent(out) :: eof
    logical, intent(in), optional :: skip_ws

    integer :: ios
    character :: c
    logical :: ignore

    !+PJK
    ios = 0
    !-PJK
    eof = .false.
    if (.not.present(skip_ws)) then
       ignore = .false.
    else
       ignore = skip_ws
    end if

    do
       if (pushed_index > 0) then
          ! there is a character pushed back on, most likely from the number parsing
          c = pushed_char(pushed_index:pushed_index)
          pushed_index = pushed_index - 1
       else
          read (unit=unit, fmt="(a)", advance="no", iostat=ios) c
       end if
       if (ios == end_of_record) then
          cycle
       else if (ios == end_of_file) then
          eof = .true.
          exit
       else if (iachar(c) <= 31) then  !  PJK from 32
          ! non printing ascii characters
          cycle
       else if (ignore .and. c == " ") then
          cycle
       else
          popped = c
          exit
       end if
    end do

  end function pop_char