This module provides an interface to the POSIX calls for tty I/O
control. For a complete description of these calls, see the POSIX or
Unix manual pages. It is only available for those Unix versions
that support POSIX termios style tty I/O control (and then
only if configured at installation time).
All functions in this module take a file descriptor fd as their
first argument. This must be an integer file descriptor, such as
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:
Return a list containing the tty attributes for file descriptor
fd, as follows:
[iflag, oflag, cflag,
lflag, ispeed, ospeed, cc
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
- 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: TCSANOW to change immediately,
TCSADRAIN to change after transmitting all queued output,
or TCSAFLUSH to change after transmitting all queued
output and discarding all queued input.
- 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
Wait until all output written to file descriptor fd has been
- 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.
- 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.
- Module tty:
- Convenience functions for common terminal control
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