.. module:: os
   :synopsis: basic "operating system" services

The os module contains functions for filesystem access and urandom function.

The filesystem has / as the root directory and the available physical drives are accessible from here. They are currently:

/flash -- the internal flash filesystem

/sd -- the SD card (if it exists)

.. only:: port_pyboard

    On boot up, the current directory is ``/flash`` if no SD card is inserted,
    otherwise it is ``/sd``.

.. only:: port_wipy

    On boot up, the current directory is ``/flash``.

.. function:: chdir(path)

   Change current directory.

.. function:: getcwd()

   Get the current directory.

.. function:: listdir([dir])

   With no argument, list the current directory.  Otherwise list the given directory.

.. function:: mkdir(path)

   Create a new directory.

.. function:: remove(path)

   Remove a file.

.. function:: rmdir(path)

   Remove a directory.

.. function:: rename(old_path, new_path)

   Rename a file.

.. function:: stat(path)

   Get the status of a file or directory.

.. function:: sync()

   Sync all filesystems.

.. function:: urandom(n)

   Return a bytes object with n random bytes, generated by the hardware
   random number generator.

.. only:: port_wipy

    .. function:: mount(block_device, mount_point, \*, readonly=False)

       Mounts a block device (like an ``SD`` object) in the specified mount
       point. Example::

          os.mount(sd, '/sd')

    .. function:: unmount(path)

       Unmounts a prevoulsy mounted block device from the given path.

    .. function:: mkfs(block_device or path)

       Formats the specified path, must be either ``/flash`` or ``/sd``.
       A block device can also be passed like an ``SD`` object before
       being mounted.

    .. function:: dupterm(stream_object)

       Duplicate the terminal (the REPL) on the passed stream-like object.
       The given object must at least implement the ``.read()`` and ``.write()`` methods.

.. data:: sep

   separation character used in paths