:mod:`pty` --- Pseudo-terminal utilities

========================================

.. module:: pty

   :platform: IRIX, Linux

   :synopsis: Pseudo-Terminal Handling for SGI and Linux.

.. moduleauthor:: Steen Lumholt

.. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il>

The :mod:`pty` module defines operations for handling the pseudo-terminal

concept: starting another process and being able to write to and read from its

controlling terminal programmatically.

Because pseudo-terminal handling is highly platform dependant, there is code to

do it only for SGI and Linux. (The Linux code is supposed to work on other

platforms, but hasn't been tested yet.)

The :mod:`pty` module defines the following functions:

.. function:: fork()

   Fork. Connect the child's controlling terminal to a pseudo-terminal. Return

   value is ``(pid, fd)``. Note that the child  gets *pid* 0, and the *fd* is

   *invalid*. The parent's return value is the *pid* of the child, and *fd* is a

   file descriptor connected to the child's controlling terminal (and also to the

   child's standard input and output).

.. function:: openpty()

   Open a new pseudo-terminal pair, using :func:`os.openpty` if possible, or

   emulation code for SGI and generic Unix systems. Return a pair of file

   descriptors ``(master, slave)``, for the master and the slave end, respectively.

.. function:: spawn(argv[, master_read[, stdin_read]])

   Spawn a process, and connect its controlling terminal with the current

   process's standard io. This is often used to baffle programs which insist on

   reading from the controlling terminal.

   The functions *master_read* and *stdin_read* should be functions which read from

   a file descriptor. The defaults try to read 1024 bytes each time they are

   called.