--- rest25/library/subprocess.rst	2008-12-19 16:58:07.000000000 +0900
+++ rest262/library/subprocess.rst	2009-04-05 05:02:09.000000000 +0900
@@ -3,54 +3,54 @@
 ===========================================
 
 .. module:: subprocess
    :synopsis: Subprocess management.
 .. moduleauthor:: Peter Åstrand <astrand@lysator.liu.se>
 .. sectionauthor:: Peter Åstrand <astrand@lysator.liu.se>
 
 
 .. versionadded:: 2.4
 
 The :mod:`subprocess` module allows you to spawn new processes, connect to their
 input/output/error pipes, and obtain their return codes.  This module intends to
-replace several other, older modules and functions, such as:
-
-.. % XXX Should add pointers to this module to at least the popen2
-.. % and commands sections.
-
-::
+replace several other, older modules and functions, such as::
 
    os.system
    os.spawn*
    os.popen*
    popen2.*
    commands.*
 
 Information about how the :mod:`subprocess` module can be used to replace these
 modules and functions can be found in the following sections.
 
+.. seealso::
+
+   :pep:`324` -- PEP proposing the subprocess module
+
 
 Using the subprocess Module
 ---------------------------
 
 This module defines one class called :class:`Popen`:
 
 
 .. class:: Popen(args, bufsize=0, executable=None, stdin=None, stdout=None, stderr=None, preexec_fn=None, close_fds=False, shell=False, cwd=None, env=None, universal_newlines=False, startupinfo=None, creationflags=0)
 
    Arguments are:
 
-   *args* should be a string, or a sequence of program arguments.  The program to
-   execute is normally the first item in the args sequence or string, but can be
-   explicitly set by using the executable argument.
+   *args* should be a string, or a sequence of program arguments.  The program
+   to execute is normally the first item in the args sequence or the string if a
+   string is given, but can be explicitly set by using the *executable*
+   argument.
 
    On Unix, with *shell=False* (default): In this case, the Popen class uses
    :meth:`os.execvp` to execute the child program. *args* should normally be a
    sequence.  A string will be treated as a sequence with the string as the only
    item (the program to execute).
 
    On Unix, with *shell=True*: If args is a string, it specifies the command string
    to execute through the shell.  If *args* is a sequence, the first item specifies
    the command string, and any additional items will be treated as additional shell
    arguments.
 
    On Windows: the :class:`Popen` class uses CreateProcess() to execute the child
@@ -64,93 +64,113 @@
    built-in open() function: :const:`0` means unbuffered, :const:`1` means line
    buffered, any other positive value means use a buffer of (approximately) that
    size.  A negative *bufsize* means to use the system default, which usually means
    fully buffered.  The default value for *bufsize* is :const:`0` (unbuffered).
 
    The *executable* argument specifies the program to execute. It is very seldom
    needed: Usually, the program to execute is defined by the *args* argument. If
    ``shell=True``, the *executable* argument specifies which shell to use. On Unix,
    the default shell is :file:`/bin/sh`.  On Windows, the default shell is
    specified by the :envvar:`COMSPEC` environment variable.
 
    *stdin*, *stdout* and *stderr* specify the executed programs' standard input,
-   are ``PIPE``, an existing file descriptor (a positive integer), an
+   are :data:`PIPE`, an existing file descriptor (a positive integer), an
-   existing file object, and ``None``.  ``PIPE`` indicates that a new pipe
+   existing file object, and ``None``.  :data:`PIPE` indicates that a new pipe
-   to the child should be created.  With ``None``, no redirection will occur;
+   to the child should be created.  With ``None``, no redirection will occur;
-   the child's file handles will be inherited from the parent.  Additionally,
+   the child's file handles will be inherited from the parent.  Additionally,
-   *stderr* can be ``STDOUT``, which indicates that the stderr data from the applications should be captured
+   *stderr* can be :data:`STDOUT`, which indicates that the stderr data from the
-   into the same file handle as for stdout.
+   applications should be captured into the same file handle as for stdout.
 
    If *preexec_fn* is set to a callable object, this object will be called in the
    child process just before the child is executed. (Unix only)
 
    If *close_fds* is true, all file descriptors except :const:`0`, :const:`1` and
-   :const:`2` will be closed before the child process is executed. (Unix only)
+   :const:`2` will be closed before the child process is executed. (Unix only).
+   Or, on Windows, if *close_fds* is true then no handles will be inherited by the
+   child process.  Note that on Windows, you cannot set *close_fds* to true and
+   also redirect the standard handles by setting *stdin*, *stdout* or *stderr*.
 
    If *shell* is :const:`True`, the specified command will be executed through the
    shell.
 
    If *cwd* is not ``None``, the child's current directory will be changed to *cwd*
    before it is executed.  Note that this directory is not considered when
    searching the executable, so you can't specify the program's path relative to
    *cwd*.
 
-   If *env* is not ``None``, it defines the environment variables for the new
-   process.
+   If *env* is not ``None``, it must be a mapping that defines the environment
+   variables for the new process; these are used instead of inheriting the current
+   process' environment, which is the default behavior.
 
    If *universal_newlines* is :const:`True`, the file objects stdout and stderr are
    opened as text files, but lines may be terminated by any of ``'\n'``, the Unix
-   end-of-line convention, ``'\r'``, the Macintosh convention or ``'\r\n'``, the
+   end-of-line convention, ``'\r'``, the old Macintosh convention or ``'\r\n'``, the
    Windows convention. All of these external representations are seen as ``'\n'``
    by the Python program.
 
    .. note::
 
       This feature is only available if Python is built with universal newline support
       (the default).  Also, the newlines attribute of the file objects :attr:`stdout`,
       :attr:`stdin` and :attr:`stderr` are not updated by the communicate() method.
 
    The *startupinfo* and *creationflags*, if given, will be passed to the
    underlying CreateProcess() function.  They can specify things such as appearance
    of the main window and priority for the new process.  (Windows only)
 
 
+.. data:: PIPE
+
+   Special value that can be used as the *stdin*, *stdout* or *stderr* argument
+   to :class:`Popen` and indicates that a pipe to the standard stream should be
+   opened.
+
+
+.. data:: STDOUT
+
+   Special value that can be used as the *stderr* argument to :class:`Popen` and
+   indicates that standard error should go into the same handle as standard
+   output.
+
+
 Convenience Functions
 ^^^^^^^^^^^^^^^^^^^^^
 
 This module also defines two shortcut functions:
 
 
 .. function:: call(*popenargs, **kwargs)
 
    Run command with arguments.  Wait for command to complete, then return the
    :attr:`returncode` attribute.
 
    The arguments are the same as for the Popen constructor.  Example::
 
       retcode = call(["ls", "-l"])
 
 
 .. function:: check_call(*popenargs, **kwargs)
 
    Run command with arguments.  Wait for command to complete. If the exit code was
-   zero then return, otherwise raise :exc:`CalledProcessError.` The
+   zero then return, otherwise raise :exc:`CalledProcessError`. The
    :exc:`CalledProcessError` object will have the return code in the
    :attr:`returncode` attribute.
 
    The arguments are the same as for the Popen constructor.  Example::
 
       check_call(["ls", "-l"])
 
+   .. versionadded:: 2.5
+
 
 Exceptions
 ^^^^^^^^^^
 
 Exceptions raised in the child process, before the new program has started to
 execute, will be re-raised in the parent.  Additionally, the exception object
 will have one extra attribute called :attr:`child_traceback`, which is a string
 containing traceback information from the childs point of view.
 
 The most common exception raised is :exc:`OSError`.  This occurs, for example,
 when trying to execute a non-existent file.  Applications should prepare for
 :exc:`OSError` exceptions.
@@ -167,80 +187,136 @@
 
 Unlike some other popen functions, this implementation will never call /bin/sh
 implicitly.  This means that all characters, including shell metacharacters, can
 safely be passed to child processes.
 
 
 Popen Objects
 -------------
 
 Instances of the :class:`Popen` class have the following methods:
 
 
-.. method:: XXX Class.poll()
+.. method:: Popen.poll()
+
-   Check if child process has terminated.  Returns returncode attribute.
+   Check if child process has terminated.  Set and return :attr:`returncode`
+   attribute.
+
 
-.. method:: XXX Class.wait()
+.. method:: Popen.wait()
 
-   Wait for child process to terminate.  Returns returncode attribute.
+   Wait for child process to terminate.  Set and return :attr:`returncode`
+   attribute.
 
+   .. warning::
 
+      This will deadlock if the child process generates enough output to a
+      stdout or stderr pipe such that it blocks waiting for the OS pipe buffer
+      to accept more data.  Use :meth:`communicate` to avoid that.
 
 
-.. method:: XXX Class.communicate(input=None)
+.. method:: Popen.communicate(input=None)
 
    Interact with process: Send data to stdin.  Read data from stdout and stderr,
    until end-of-file is reached.  Wait for process to terminate. The optional
    *input* argument should be a string to be sent to the child process, or
    ``None``, if no data should be sent to the child.
 
-   communicate() returns a tuple (stdout, stderr).
+   :meth:`communicate` returns a tuple ``(stdoutdata, stderrdata)``.
+
+   Note that if you want to send data to the process's stdin, you need to create
+   the Popen object with ``stdin=PIPE``.  Similarly, to get anything other than
+   ``None`` in the result tuple, you need to give ``stdout=PIPE`` and/or
+   ``stderr=PIPE`` too.
 
    .. note::
 
-      The data read is buffered in memory, so do not use this method if the data size
-      is large or unlimited.
+      The data read is buffered in memory, so do not use this method if the data
+      size is large or unlimited.
+
+
+.. method:: Popen.send_signal(signal)
+
+   Sends the signal *signal* to the child.
+
+   .. note::
+
+      On Windows only SIGTERM is supported so far. It's an alias for
+      :meth:`terminate`.
+
+   .. versionadded:: 2.6
+
+
+.. method:: Popen.terminate()
+
+   Stop the child. On Posix OSs the method sends SIGTERM to the
+   child. On Windows the Win32 API function :cfunc:`TerminateProcess` is called
+   to stop the child.
+
+   .. versionadded:: 2.6
+
+
+.. method:: Popen.kill()
+
+   Kills the child. On Posix OSs the function sends SIGKILL to the child.
+   On Windows :meth:`kill` is an alias for :meth:`terminate`.
+
+   .. versionadded:: 2.6
+
 
 The following attributes are also available:
 
+.. warning::
+   Use :meth:`communicate` rather than :meth:`.stdin.write`,
+   :meth:`.stdout.read` or :meth:`.stderr.read` to avoid deadlocks due
+   to any of the other OS pipe buffers filling up and blocking the child
+   process.
 
-.. attribute:: XXX Class.stdin
+.. attribute:: Popen.stdin
 
-   If the *stdin* argument is ``PIPE``, this attribute is a file object that
-   provides input to the child process.  Otherwise, it is ``None``.
+   If the *stdin* argument was :data:`PIPE`, this attribute is a file object
+   that provides input to the child process.  Otherwise, it is ``None``.
 
 
-.. attribute:: XXX Class.stdout
+.. attribute:: Popen.stdout
 
-   If the *stdout* argument is ``PIPE``, this attribute is a file object that
-   provides output from the child process.  Otherwise, it is ``None``.
+   If the *stdout* argument was :data:`PIPE`, this attribute is a file object
+   that provides output from the child process.  Otherwise, it is ``None``.
 
 
-.. attribute:: XXX Class.stderr
+.. attribute:: Popen.stderr
 
-   If the *stderr* argument is ``PIPE``, this attribute is file object that
-   provides error output from the child process.  Otherwise, it is ``None``.
+   If the *stderr* argument was :data:`PIPE`, this attribute is a file object
+   that provides error output from the child process.  Otherwise, it is
+   ``None``.
 
 
+
+
-.. attribute:: XXX Class.pid
+.. attribute:: Popen.pid
 
    The process ID of the child process.
 
 
-.. attribute:: XXX Class.returncode
+.. attribute:: Popen.returncode
+
-   The child return code.  A ``None`` value indicates that the process hasn't
-   terminated yet.  A negative value -N indicates that the child was terminated by
-   signal N (Unix only).
+   The child return code, set by :meth:`poll` and :meth:`wait` (and indirectly
+   by :meth:`communicate`).  A ``None`` value indicates that the process
+   hasn't terminated yet.
+
+   A negative value ``-N`` indicates that the child was terminated by signal
+   ``N`` (Unix only).
 
 
+.. _subprocess-replacements:
 
 Replacing Older Functions with the subprocess Module
 ----------------------------------------------------
 
 In this section, "a ==> b" means that b can be used as a replacement for a.
 
 .. note::
 
    All functions in this section fail (more or less) silently if the executed
    program cannot be found; this module raises an :exc:`OSError` exception.
 
 In the following examples, we assume that the subprocess module is imported with
@@ -248,26 +324,26 @@
 
 
 Replacing /bin/sh shell backquote
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 ::
 
    output=`mycmd myarg`
    ==>
    output = Popen(["mycmd", "myarg"], stdout=PIPE).communicate()[0]
 
 
-Replacing shell pipe line
-^^^^^^^^^^^^^^^^^^^^^^^^^
+Replacing shell pipeline
+^^^^^^^^^^^^^^^^^^^^^^^^
 
 ::
 
    output=`dmesg | grep hda`
    ==>
    p1 = Popen(["dmesg"], stdout=PIPE)
    p2 = Popen(["grep", "hda"], stdin=p1.stdout, stdout=PIPE)
    output = p2.communicate()[0]
 
 
 Replacing os.system()
 ^^^^^^^^^^^^^^^^^^^^^
@@ -288,26 +364,26 @@
 A more realistic example would look like this::
 
    try:
        retcode = call("mycmd" + " myarg", shell=True)
        if retcode < 0:
            print >>sys.stderr, "Child was terminated by signal", -retcode
        else:
            print >>sys.stderr, "Child returned", retcode
    except OSError, e:
        print >>sys.stderr, "Execution failed:", e
 
 
-Replacing os.spawn\*
-^^^^^^^^^^^^^^^^^^^^
+Replacing the os.spawn family
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 P_NOWAIT example::
 
    pid = os.spawnlp(os.P_NOWAIT, "/bin/mycmd", "mycmd", "myarg")
    ==>
    pid = Popen(["/bin/mycmd", "myarg"]).pid
 
 P_WAIT example::
 
    retcode = os.spawnlp(os.P_WAIT, "/bin/mycmd", "mycmd", "myarg")
    ==>
    retcode = call(["/bin/mycmd", "myarg"])
@@ -316,36 +392,36 @@
 
    os.spawnvp(os.P_NOWAIT, path, args)
    ==>
    Popen([path] + args[1:])
 
 Environment example::
 
    os.spawnlpe(os.P_NOWAIT, "/bin/mycmd", "mycmd", "myarg", env)
    ==>
    Popen(["/bin/mycmd", "myarg"], env={"PATH": "/usr/bin"})
 
 
-Replacing os.popen\*
-^^^^^^^^^^^^^^^^^^^^
+Replacing os.popen, os.popen2, os.popen3
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 ::
 
-   pipe = os.popen(cmd, mode='r', bufsize)
+   pipe = os.popen(cmd, 'r', bufsize)
    ==>
    pipe = Popen(cmd, shell=True, bufsize=bufsize, stdout=PIPE).stdout
 
 ::
 
-   pipe = os.popen(cmd, mode='w', bufsize)
+   pipe = os.popen(cmd, 'w', bufsize)
    ==>
    pipe = Popen(cmd, shell=True, bufsize=bufsize, stdin=PIPE).stdin
 
 ::
 
    (child_stdin, child_stdout) = os.popen2(cmd, mode, bufsize)
    ==>
    p = Popen(cmd, shell=True, bufsize=bufsize,
              stdin=PIPE, stdout=PIPE, close_fds=True)
    (child_stdin, child_stdout) = (p.stdin, p.stdout)
 
 ::
@@ -360,48 +436,48 @@
     child_stdout,
     child_stderr) = (p.stdin, p.stdout, p.stderr)
 
 ::
 
    (child_stdin, child_stdout_and_stderr) = os.popen4(cmd, mode, bufsize)
    ==>
    p = Popen(cmd, shell=True, bufsize=bufsize,
              stdin=PIPE, stdout=PIPE, stderr=STDOUT, close_fds=True)
    (child_stdin, child_stdout_and_stderr) = (p.stdin, p.stdout)
 
 
-Replacing popen2.\*
-^^^^^^^^^^^^^^^^^^^
+Replacing functions from the popen2 module
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 .. note::
 
    If the cmd argument to popen2 functions is a string, the command is executed
    through /bin/sh.  If it is a list, the command is directly executed.
 
 ::
 
    (child_stdout, child_stdin) = popen2.popen2("somestring", bufsize, mode)
    ==>
    p = Popen(["somestring"], shell=True, bufsize=bufsize,
              stdin=PIPE, stdout=PIPE, close_fds=True)
    (child_stdout, child_stdin) = (p.stdout, p.stdin)
 
 ::
 
    (child_stdout, child_stdin) = popen2.popen2(["mycmd", "myarg"], bufsize, mode)
    ==>
    p = Popen(["mycmd", "myarg"], bufsize=bufsize,
              stdin=PIPE, stdout=PIPE, close_fds=True)
    (child_stdout, child_stdin) = (p.stdout, p.stdin)
 
-The popen2.Popen3 and popen2.Popen4 basically works as subprocess.Popen, except
-that:
+:class:`popen2.Popen3` and :class:`popen2.Popen4` basically work as
+:class:`subprocess.Popen`, except that:
 
-* subprocess.Popen raises an exception if the execution fails
+* :class:`Popen` raises an exception if the execution fails.
 
 * the *capturestderr* argument is replaced with the *stderr* argument.
 
-* stdin=PIPE and stdout=PIPE must be specified.
+* ``stdin=PIPE`` and ``stdout=PIPE`` must be specified.
 
 * popen2 closes all file descriptors by default, but you have to specify
-  close_fds=True with subprocess.Popen.
+  ``close_fds=True`` with :class:`Popen`.
 
