Ok so I have a few simple examples working for ccalling fortran functions
and subroutines from Julia.
Maybe someone will find this useful examples when first looking into
calling fortran from julia.
compile the following fortran module with
*gfortran simplemodule.f95 -o simplemodule.so -shared -fPIC*
```
!fileName = simplemodule.f95
module simpleModule
implicit none
contains
function foo(x)
integer :: foo, x
foo = x * 2
end function foo
subroutine bar(x, a, b)
integer, intent(in) :: x
integer, intent(out) :: a, b
a = x + 3
b = x * 3
end subroutine bar
subroutine keg(x, a, b)
real*8, intent(in) :: x
real*8, intent(out) :: a, b
a = x + 3.0
b = x * 3.0
end subroutine keg
subroutine ruf(x, y)
real*8, dimension(3), intent(in) :: x
real*8, dimension(3), intent(out) :: y
integer :: i
DO i = 1, 3
y(i) = 2*x(i)
END DO
end subroutine ruf
end module simplemodule
```
then you can use the following julia script to call the functions from the
shared library.
```
x1 = 7
a1 = [0]
b1 = [0]
r1 = ccall((:__simplemodule_MOD_foo,
"/home/abieler/testPrograms/fortranShardLib/simplemodule.so"), Int64,
(Ptr{Int64},), &x1)
println(r1)
println()
ccall((:__simplemodule_MOD_bar,
"/home/abieler/testPrograms/fortranShardLib/simplemodule.so"), Void,
(Ptr{Int64}, Ptr{Int64}, Ptr{Int64}), &x1, a1, b1)
println(a1[1])
println(b1[1])
println()
x2 = 7.0
a2 = Cdouble[1.0]
b2 = Cdouble[1.0]
ccall((:__simplemodule_MOD_keg,
"/home/abieler/testPrograms/fortranShardLib/simplemodule.so"), Void,
(Ptr{Float64}, Ptr{Float64}, Ptr{Float64}), &x2, a2, b2)
println(a2[1])
println(b2[1])
println()
x3 = [1.0, 2.0, 3.0]
y3 = [0.0, 0.0, 0.0]
ccall((:__simplemodule_MOD_ruf,
"/home/abieler/testPrograms/fortranShardLib/simplemodule.so"), Void,
(Ptr{Float64}, Ptr{Float64}), x3, y3)
println(y3)
```
