mirror of https://github.com/python/cpython
138 lines
4.4 KiB
ReStructuredText
138 lines
4.4 KiB
ReStructuredText
:mod:`termios` --- POSIX style tty control
|
|
==========================================
|
|
|
|
.. module:: termios
|
|
:platform: Unix
|
|
:synopsis: POSIX style tty control.
|
|
|
|
.. index::
|
|
pair: POSIX; I/O control
|
|
pair: tty; I/O control
|
|
|
|
--------------
|
|
|
|
This module provides an interface to the POSIX calls for tty I/O control. For a
|
|
complete description of these calls, see :manpage:`termios(3)` Unix manual
|
|
page. It is only available for those Unix versions that support POSIX
|
|
*termios* style tty I/O control configured during installation.
|
|
|
|
.. availability:: Unix.
|
|
|
|
All functions in this module take a file descriptor *fd* as their first
|
|
argument. This can be an integer file descriptor, such as returned by
|
|
``sys.stdin.fileno()``, or a :term:`file object`, such as ``sys.stdin`` itself.
|
|
|
|
This module also defines all the constants needed to work with the functions
|
|
provided here; these have the same name as their counterparts in C. Please
|
|
refer to your system documentation for more information on using these terminal
|
|
control interfaces.
|
|
|
|
The module defines the following functions:
|
|
|
|
|
|
.. function:: tcgetattr(fd)
|
|
|
|
Return a list containing the tty attributes for file descriptor *fd*, as
|
|
follows: ``[iflag, oflag, cflag, lflag, ispeed, ospeed, cc]`` where *cc* is a
|
|
list of the tty special characters (each a string of length 1, except the
|
|
items with indices :const:`VMIN` and :const:`VTIME`, which are integers when
|
|
these fields are defined). The interpretation of the flags and the speeds as
|
|
well as the indexing in the *cc* array must be done using the symbolic
|
|
constants defined in the :mod:`termios` module.
|
|
|
|
|
|
.. function:: tcsetattr(fd, when, attributes)
|
|
|
|
Set the tty attributes for file descriptor *fd* from the *attributes*, which is
|
|
a list like the one returned by :func:`tcgetattr`. The *when* argument
|
|
determines when the attributes are changed:
|
|
|
|
.. data:: TCSANOW
|
|
|
|
Change attributes immediately.
|
|
|
|
.. data:: TCSADRAIN
|
|
|
|
Change attributes after transmitting all queued output.
|
|
|
|
.. data:: TCSAFLUSH
|
|
|
|
Change attributes after transmitting all queued output and
|
|
discarding all queued input.
|
|
|
|
|
|
.. function:: tcsendbreak(fd, duration)
|
|
|
|
Send a break on file descriptor *fd*. A zero *duration* sends a break for
|
|
0.25--0.5 seconds; a nonzero *duration* has a system dependent meaning.
|
|
|
|
|
|
.. function:: tcdrain(fd)
|
|
|
|
Wait until all output written to file descriptor *fd* has been transmitted.
|
|
|
|
|
|
.. function:: tcflush(fd, queue)
|
|
|
|
Discard queued data on file descriptor *fd*. The *queue* selector specifies
|
|
which queue: :const:`TCIFLUSH` for the input queue, :const:`TCOFLUSH` for the
|
|
output queue, or :const:`TCIOFLUSH` for both queues.
|
|
|
|
|
|
.. function:: tcflow(fd, action)
|
|
|
|
Suspend or resume input or output on file descriptor *fd*. The *action*
|
|
argument can be :const:`TCOOFF` to suspend output, :const:`TCOON` to restart
|
|
output, :const:`TCIOFF` to suspend input, or :const:`TCION` to restart input.
|
|
|
|
|
|
.. function:: tcgetwinsize(fd)
|
|
|
|
Return a tuple ``(ws_row, ws_col)`` containing the tty window size for file
|
|
descriptor *fd*. Requires :const:`termios.TIOCGWINSZ` or
|
|
:const:`termios.TIOCGSIZE`.
|
|
|
|
.. versionadded:: 3.11
|
|
|
|
|
|
.. function:: tcsetwinsize(fd, winsize)
|
|
|
|
Set the tty window size for file descriptor *fd* from *winsize*, which is
|
|
a two-item tuple ``(ws_row, ws_col)`` like the one returned by
|
|
:func:`tcgetwinsize`. Requires at least one of the pairs
|
|
(:const:`termios.TIOCGWINSZ`, :const:`termios.TIOCSWINSZ`);
|
|
(:const:`termios.TIOCGSIZE`, :const:`termios.TIOCSSIZE`) to be defined.
|
|
|
|
.. versionadded:: 3.11
|
|
|
|
|
|
.. seealso::
|
|
|
|
Module :mod:`tty`
|
|
Convenience functions for common terminal control operations.
|
|
|
|
|
|
.. _termios-example:
|
|
|
|
Example
|
|
-------
|
|
|
|
Here's a function that prompts for a password with echoing turned off. Note the
|
|
technique using a separate :func:`tcgetattr` call and a :keyword:`try` ...
|
|
:keyword:`finally` statement to ensure that the old tty attributes are restored
|
|
exactly no matter what happens::
|
|
|
|
def getpass(prompt="Password: "):
|
|
import termios, sys
|
|
fd = sys.stdin.fileno()
|
|
old = termios.tcgetattr(fd)
|
|
new = termios.tcgetattr(fd)
|
|
new[3] = new[3] & ~termios.ECHO # lflags
|
|
try:
|
|
termios.tcsetattr(fd, termios.TCSADRAIN, new)
|
|
passwd = input(prompt)
|
|
finally:
|
|
termios.tcsetattr(fd, termios.TCSADRAIN, old)
|
|
return passwd
|
|
|