diff options
author | Guido van Rossum <guido@python.org> | 1995-03-31 12:26:24 (GMT) |
---|---|---|
committer | Guido van Rossum <guido@python.org> | 1995-03-31 12:26:24 (GMT) |
commit | f9adf48750fc9cbfbb8c71275b4b337ffc7d9b51 (patch) | |
tree | 0c436088ff68957bb8b1f30896e2af0dee3ddc7b /Doc/lib | |
parent | 86dc1e696d309529e34c260052f277c1740c1951 (diff) | |
download | cpython-f9adf48750fc9cbfbb8c71275b4b337ffc7d9b51.zip cpython-f9adf48750fc9cbfbb8c71275b4b337ffc7d9b51.tar.gz cpython-f9adf48750fc9cbfbb8c71275b4b337ffc7d9b51.tar.bz2 |
documented termios + TERMIOS
Diffstat (limited to 'Doc/lib')
-rw-r--r-- | Doc/lib/libtermios.tex | 107 |
1 files changed, 106 insertions, 1 deletions
diff --git a/Doc/lib/libtermios.tex b/Doc/lib/libtermios.tex index 8fe6f51..e55aab4 100644 --- a/Doc/lib/libtermios.tex +++ b/Doc/lib/libtermios.tex @@ -1,3 +1,108 @@ \section{Built-in Module \sectcode{termios}} +\bimodindex{termios} +\indexii{Posix}{I/O control} +\indexii{tty}{I/O control} -To be provided. +\renewcommand{\indexsubitem}{(in module termios)} + +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 \code{termios} style tty I/O control (and then +only if configured at installation time). + +All functions in this module take a file descriptor \var{fd} as their +first argument. This must be an integer file descriptor, such as +returned by \code{sys.stdin.fileno()}. + +This module should be used in conjunction with the \code{TERMIOS} +module, which defines the relevant symbolic constants (see the next +section). + +The module defines the following functions: + +\begin{funcdesc}{tcgetattr}{fd} +Return a list containing the tty attributes for file descriptor +\var{fd}, as follows: \code{[\var{iflag}, \var{oflag}, \var{cflag}, +\var{lflag}, \var{ispeed}, \var{ospeed}, \var{cc}]} where \var{cc} is +a list of the tty special characters (each a string of length 1, +except the items with indices \code{VMIN} and \code{VTIME}, which are +integers when these fields are defined). The interpretation of the +flags and the speeds as well as the indexing in the \var{cc} array +must be done using the symbolic constants defined in the +\code{TERMIOS} module. +\end{funcdesc} + +\begin{funcdesc}{tcsetattr}{fd\, when\, attributes} +Set the tty attributes for file descriptor \var{fd} from the +\var{attributes}, which is a list like the one returned by +\code{tcgetattr()}. The \var{when} argument determines when the +attributes are changed: \code{TERMIOS.TCSANOW} to change immediately, +\code{TERMIOS.TCSADRAIN} to change after transmitting all queued +output, or \code{TERMIOS.TCSAFLUSH} to change after transmitting all +queued output and discarding all queued input. +\end{funcdesc} + +\begin{funcdesc}{tcsendbreak}{fd\, duration} +Send a break on file descriptor \var{fd}. A zero \var{duration} sends +a break for 0.25--0.5 seconds; a nonzero \var{duration} has a system +dependent meaning. +\end{funcdesc} + +\begin{funcdesc}{tcdrain}{fd} +Wait until all output written to file descriptor \var{fd} has been +transmitted. +\end{funcdesc} + +\begin{funcdesc}{tcflush}{fd\, queue} +Discard queued data on file descriptor \var{fd}. The \var{queue} +selector specifies which queue: \code{TERMIOS.TCIFLUSH} for the input +queue, \code{TERMIOS.TCOFLUSH} for the output queue, or +\code{TERMIOS.TCIOFLUSH} for both queues. +\end{funcdesc} + +\begin{funcdesc}{tcflow}{fd\, action} +Suspend or resume input or output on file descriptor \var{fd}. The +\var{action} argument can be \code{TERMIOS.TCOOFF} to suspend output, +\code{TERMIOS.TCOON} to restart output, \code{TERMIOS.TCIOFF} to +suspend input, or \code{TERMIOS.TCION} to restart input. +\end{funcdesc} + +\subsection{Example} +\nodename{termios Example} + +Here's a function that prompts for a password with echoing turned off. +Note the technique using a separate \code{termios.tcgetattr()} call +and a \code{try {\ldots} finally} statement to ensure that the old tty +attributes are restored exactly no matter what happens: + +\begin{verbatim} +def getpass(prompt = "Password: "): + import termios, 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 = raw_input(prompt) + finally: + termios.tcsetattr(fd, TERMIOS.TCSADRAIN, old) + return passwd +\end{verbatim} + + +\section{Standard Module \sectcode{TERMIOS}} +\stmodindex{TERMIOS} +\indexii{Posix}{I/O control} +\indexii{tty}{I/O control} + +\renewcommand{\indexsubitem}{(in module TERMIOS)} + +This module defines the symbolic constants required to use the +\code{termios} module (see the previous section). See the Posix or +\UNIX{} manual pages (or the source) for a list of those constants. + +Note: this module resides in a system-dependent subdirectory of the +Python library directory. You may have to generate it for your +particular system using the script \file{Tools/scripts/h2py.py}. |