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Title: termios — POSIX style tty control — Python 3.13.18 documentation Authors: Venue: pydoc Year: 2001 Canonical: pydoc:termios@3.13 URL: https://docs.python.org/3.13/library/termios.html Collector: pydoc OA: true ABSTRACT termios — POSIX style tty control — Python 3.13.18 documentation Navigation index modules | next | previous | Python » 3.13.18 Documentation » The Python standard library » Unix-specific services » termios — POSIX style tty control | Theme Auto Light Dark | termios — POSIX style tty control¶ This module provides an interface to the POSIX calls for tty I/O control. For a complete description of these calls, see 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 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: termios.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 VMIN and 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 termios module. termios.tcsetattr(fd, when, attributes)¶ Set the tty attributes for file descriptor fd from the attributes, which is a list like the one returned by tcgetattr(). The when argument determines when the attributes are changed: termios.TCSANOW¶ Change attributes immediately. termios.TCSADRAIN¶ Change attributes after transmitting all queued output. termios.TCSAFLUSH¶ Change attributes after transmitting all queued output and discarding all queued input. termios.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. termios.tcdrain(fd)¶ Wait until all output written to file descriptor fd has been transmitted. termios.tcflush(fd, queue)¶ Discard queued data on file descriptor fd. The queue selector specifies which queue: TCIFLUSH for the input queue, TCOFLUSH for the output queue, or TCIOFLUSH for both queues. termios.tcflow(fd, action)¶ Suspend or resume input or output on file descriptor fd. The action argument can be TCOOFF to suspend output, TCOON to restart output, TCIOFF to suspend input, or TCION to restart input. termios.tcgetwinsize(fd)¶ Return a tuple (ws_row, ws_col) containing the tty window size for file descriptor fd. Requires termios.TIOCGWINSZ or termios.TIOCGSIZE. Added in version 3.11. termios.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 tcgetwinsize(). Requires at least one of the pairs (termios.TIOCGWINSZ, termios.TIOCSWINSZ); (termios.TIOCGSIZE, termios.TIOCSSIZE) to be defined. Added in version 3.11. See also Module ttyConvenience functions for common terminal control operations. Example¶ Here’s a function that prompts for a password with echoing turned off. Note the technique using a separate tcgetattr() call and a try … 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 Table of Contents termios — POSIX style tty control Example Previous topic grp — The group database Next topic tty — Terminal control functions This page Report a bug Show source « Navigation index modules | next | previous | Python » 3.13.18 Documentation » The Python standard library » Unix-specific services » termios — POSIX style tty control | Theme Auto Light Dark | © Copyright 2001-2026, Python Software Foundation. This page is licensed under the Python Software Foundation License Version 2. Examples, recipes, and other code in the documentation are additionally licensed under the Zero Clause BSD License. See History and License for more information. The Python Software Foundation is a non-profit corporation. Please donate. Last updated on Oct 26, 2026 (13:10 UTC). Found a bug? Created using Sphinx 8.2.3.