| !! |
| !! Demonstrates COMMON block nightmare |
| !! |
| !! J. Overbey 8/18/08 |
| !! |
| program main |
| implicit none |
| |
| external change_c |
| |
| common a, b |
| integer :: a |
| real :: b |
| |
| common /common/ c, d, e /common2/ f, g, /common3/ h |
| complex :: c |
| dimension c(3) |
| ! double precision :: d, e, f, g, h |
| double precision :: d |
| double precision :: e |
| double precision :: f |
| double precision :: g |
| double precision :: h |
| |
| a = 1 |
| b = 2.3 |
| c = (4,5) |
| print *, a, b, c |
| |
| call change_ab |
| call change_c |
| |
| print *, "Now the first two variables below should have garbage values" |
| print *, "and the third should be (5,6):" |
| print *, a, b, c |
| end program |
| |
| subroutine change_ab |
| implicit none |
| |
| ! q and r are stored at the same place in memory as a and b above, |
| ! but they have the wrong types |
| common q, r |
| real :: q |
| integer :: r |
| |
| q = 4.5 |
| r = 6 |
| print *, q, r |
| end subroutine |
