add err handling to example

example/system/example_get_file_size.f90

@@ -1,10 +1,21 @@
 program example_get_file_size
+ use, intrinsic :: iso_fortran_env, only: int64
  use stdlib_system, only: get_file_size
+ use stdlib_error, only: state_type
  implicit none
+
+ type(state_type) :: err
+ integer(int64) :: size
 
- character(*), parameter :: path = "src"
+ character(*), parameter :: path = "path/to/check"
+
+ size = get_file_size(path, err)
 
- print *, get_file_size(path)
+ if (err%ok()) then
+ print *, "Size in bytes = ", size
+ else
+ print *, "Error!: ", err%print()
+ end if
 
 end program example_get_file_size