! Reads values for an array from a file, sorts with selection sort
        program sort
	implicit none
        integer, parameter :: maxsize = 10
        real, dimension(maxsize) :: a
        logical :: exceed = .false.
        character(len=20) :: filename
        integer :: i
        integer :: iptr
        integer :: j
        integer :: nvals = 0
        integer :: status
        real :: temp

        write(*, 1000)
1000    format (1x, 'Enter the name of the file: ')
        read (*, '(A20)') filename
        open (unit = 9, file = filename, status='old', action='read', &
                iostat=status)
        fileopen: if (status==0) then
            do
                read(9, *, iostat=status) temp
                if (status /= 0) exit
                nvals = nvals+1
                size: if (nvals <= maxsize) then
                    a(nvals) = temp
                else
                    exceed = .true.
                end if size
            end do

            toobig: if (exceed) then
                write(*,1020) nvals, maxsize
1020            format('Max array size exceeded: ', I6, '>', I6)
            else toobig
                outer: do i = 1, nvals-1
                    iptr = i
                    inner: do j = i+1, nvals
                        minval: if (a(j) < a(iptr)) then
                            iptr = j
                        end if minval
                    end do inner

                    swap: if( i/= iptr) then
                        temp = a(i)
                        a(i) = a(iptr)
                        a(iptr) = temp
                    end if swap
                end do outer

                write(*, '(A)a') 'The sorted data:'
                write(*, 1040) (a(i),i=1, nvals)
1040            format (4x, f10.4)
            end if toobig
        else fileopen
            write(*,1050) status
1050        format(1x, 'File open failed-status = ', I6)
        end if fileopen
        end program