circuitpython/docs/library/uos.rst

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:mod:`uos` -- basic "operating system" services
===============================================
.. module:: uos
:synopsis: basic "operating system" services
The ``os`` module contains functions for filesystem access and ``urandom``
function.
Port specifics
--------------
The filesystem has ``/`` as the root directory and the
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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``.
Functions
---------
.. function:: chdir(path)
Change current directory.
.. function:: getcwd()
Get the current directory.
.. function:: ilistdir([dir])
This function returns an iterator which then yields 3-tuples corresponding to
the entries in the directory that it is listing. With no argument it lists the
current directory, otherwise it lists the directory given by `dir`.
The 3-tuples have the form `(name, type, inode)`:
- `name` is a string (or bytes if `dir` is a bytes object) and is the name of
the entry;
- `type` is an integer that specifies the type of the entry, with 0x4000 for
directories and 0x8000 for regular files;
- `inode` is an integer corresponding to the inode of the file, and may be 0
for filesystems that don't have such a notion.
.. 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.
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.. function:: rename(old_path, new_path)
Rename a file.
.. function:: stat(path)
Get the status of a file or directory.
.. function:: statvfs(path)
Get the status of a fileystem.
Returns a tuple with the filesystem information in the following order:
* ``f_bsize`` -- file system block size
* ``f_frsize`` -- fragment size
* ``f_blocks`` -- size of fs in f_frsize units
* ``f_bfree`` -- number of free blocks
* ``f_bavail`` -- number of free blocks for unpriviliged users
* ``f_files`` -- number of inodes
* ``f_ffree`` -- number of free inodes
* ``f_favail`` -- number of free inodes for unpriviliged users
* ``f_flag`` -- mount flags
* ``f_namemax`` -- maximum filename length
Parameters related to inodes: ``f_files``, ``f_ffree``, ``f_avail``
and the ``f_flags`` parameter may return ``0`` as they can be unavailable
in a port-specific implementation.
.. function:: sync()
Sync all filesystems.
.. function:: urandom(n)
Return a bytes object with n random bytes. Whenever possible, it is
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)
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Unmounts a previously 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.