mirror of
				https://github.com/python/cpython.git
				synced 2025-11-03 23:21:29 +00:00 
			
		
		
		
	parameters (like \UNIX) are commonly entered using an empty group to separate the markup from a following inter-word space; this is not needed when the next character is punctuation, or the markup is the last thing in the enclosing group. These cases were marked inconsistently; the empty group is now *only* used when needed.
		
			
				
	
	
		
			127 lines
		
	
	
	
		
			4.5 KiB
		
	
	
	
		
			TeX
		
	
	
	
	
	
			
		
		
	
	
			127 lines
		
	
	
	
		
			4.5 KiB
		
	
	
	
		
			TeX
		
	
	
	
	
	
\section{\module{termios} ---
 | 
						|
         \POSIX{} style tty control}
 | 
						|
 | 
						|
\declaremodule{builtin}{termios}
 | 
						|
  \platform{Unix}
 | 
						|
\modulesynopsis{\POSIX\ style tty control.}
 | 
						|
 | 
						|
\indexii{\POSIX}{I/O control}
 | 
						|
\indexii{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 the \POSIX{} or
 | 
						|
\UNIX{} manual pages.  It is only available for those \UNIX{} versions
 | 
						|
that support \POSIX{} \emph{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 can be an integer file descriptor, such as
 | 
						|
returned by \code{sys.stdin.fileno()}, or a file object, such as
 | 
						|
\code{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:
 | 
						|
 | 
						|
\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}\code{]} where
 | 
						|
\var{cc} is a list of the tty special characters (each a string of
 | 
						|
length 1, except the items with indices \constant{VMIN} and
 | 
						|
\constant{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 \module{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
 | 
						|
\function{tcgetattr()}.  The \var{when} argument determines when the
 | 
						|
attributes are changed: \constant{TCSANOW} to change immediately,
 | 
						|
\constant{TCSADRAIN} to change after transmitting all queued output,
 | 
						|
or \constant{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: \constant{TCIFLUSH} for the input
 | 
						|
queue, \constant{TCOFLUSH} for the output queue, or
 | 
						|
\constant{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 \constant{TCOOFF} to suspend output,
 | 
						|
\constant{TCOON} to restart output, \constant{TCIOFF} to suspend
 | 
						|
input, or \constant{TCION} to restart input.
 | 
						|
\end{funcdesc}
 | 
						|
 | 
						|
 | 
						|
\begin{seealso}
 | 
						|
  \seemodule{tty}{Convenience functions for common terminal control
 | 
						|
                  operations.}
 | 
						|
\end{seealso}
 | 
						|
 | 
						|
 | 
						|
\subsection{Example}
 | 
						|
\nodename{termios Example}
 | 
						|
 | 
						|
Here's a function that prompts for a password with echoing turned
 | 
						|
off.  Note the technique using a separate \function{tcgetattr()} call
 | 
						|
and a \keyword{try} ... \keyword{finally} statement to ensure that the
 | 
						|
old tty attributes are restored exactly no matter what happens:
 | 
						|
 | 
						|
\begin{verbatim}
 | 
						|
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 = raw_input(prompt)
 | 
						|
    finally:
 | 
						|
        termios.tcsetattr(fd, termios.TCSADRAIN, old)
 | 
						|
    return passwd
 | 
						|
\end{verbatim}
 | 
						|
 | 
						|
 | 
						|
\section{\module{TERMIOS} ---
 | 
						|
         Constants used with the \module{termios} module}
 | 
						|
 | 
						|
\declaremodule[TERMIOSuppercase]{standard}{TERMIOS}
 | 
						|
  \platform{Unix}
 | 
						|
\modulesynopsis{Symbolic constants required to use the
 | 
						|
  \module{termios} module.}
 | 
						|
 | 
						|
 | 
						|
\indexii{\POSIX}{I/O control}
 | 
						|
\indexii{tty}{I/O control}
 | 
						|
 | 
						|
\deprecated{2.1}{Import needed constants from \refmodule{termios}
 | 
						|
                 instead.}
 | 
						|
 | 
						|
This module defines the symbolic constants required to use the
 | 
						|
\refmodule{termios}\refbimodindex{termios} module (see the previous
 | 
						|
section).  See the \POSIX{} or \UNIX{} manual pages for a list of
 | 
						|
those constants.
 |