Iso_c_binding: interface to a C function returning a string

[FedericoPerini]

@mEm

        function strlen_c(ptr) result(l) bind(c, name="strlen")
            import :: c_ptr, c_int
            type(c_ptr), value :: ptr
            integer(c_int) :: l
         end function

Not sure if this helps, but I believe the C standard function returns a size_t, not an int, so if you’re on a 64-bit platform you may receive only the first 32 bits and they may all be zeroes…?