Self study guide: Fortran 95 - University of Cambridge

We should now have a look at some examples. Let’s return to the swapmain
program from section 5.3 and implement this in two files using modules. First edit
the file swapmain.f90 and to contain:
program swapmain
use swapmod ! use statements must come first
implicit none
real :: a, b
! Read in two values
read(*,*) a, b
call swap(a,b)
write(*,*) a, b
end program swapmain
Now in the second file, called swapmod.f90 the module is defined:
module swapmod
implicit none ! you need this in every module
!
! Global declarations would appear here if any
!
contains
! routines provided by this module
subroutine swap(x, y)
real :: x, y, temp
temp = x
x = y
y = temp
end subroutine swap
end module swapmod
• Now compile the swapmod.f90 file:
f95 -c swapmod.f90
The –c option is a request to compile only and not try to produce an
executable program.
Use ls to see what files you have. You should have swapmod.mod and
swapmod.o files.
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