Lwt_sysSystem informations.
Not_available(feature) is an exception that may be raised when a feature is not available on the current system.
type feature = [ | `wait4 | 
| `get_cpu | 
| `get_affinity | 
| `set_affinity | 
| `recv_msg | 
| `send_msg | 
| `fd_passing | 
| `get_credentials | 
| `mincore | 
| `madvise | 
| `fdatasync | 
| `libev | 
 ]Features that can be tested.
val have : feature -> boolTest whether the given feature is available on the current system.
val byte_order : byte_orderThe byte order used by the computer running the program.