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-rw-r--r--Doc/library/subprocess.rst23
1 files changed, 17 insertions, 6 deletions
diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst
index 4a12b76..88eb784 100644
--- a/Doc/library/subprocess.rst
+++ b/Doc/library/subprocess.rst
@@ -125,12 +125,14 @@ This module defines one class called :class:`Popen`:
*stdin*, *stdout* and *stderr* specify the executed programs' standard input,
standard output and standard error file handles, respectively. Valid values
- are :data:`PIPE`, an existing file descriptor (a positive integer), an
- existing :term:`file object`, and ``None``. :data:`PIPE` indicates that a
- new pipe to the child should be created. With ``None``, no redirection will
- occur; the child's file handles will be inherited from the parent. Additionally,
- *stderr* can be :data:`STDOUT`, which indicates that the stderr data from the
- applications should be captured into the same file handle as for stdout.
+ are :data:`PIPE`, :data:`DEVNULL`, an existing file descriptor (a positive
+ integer), an existing :term:`file object`, and ``None``. :data:`PIPE`
+ indicates that a new pipe to the child should be created. :data:`DEVNULL`
+ indicates that the special file :data:`os.devnull` will be used. With ``None``,
+ no redirection will occur; the child's file handles will be inherited from
+ the parent. Additionally, *stderr* can be :data:`STDOUT`, which indicates
+ that the stderr data from the 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.
@@ -229,6 +231,15 @@ This module defines one class called :class:`Popen`:
Added context manager support.
+.. data:: DEVNULL
+
+ Special value that can be used as the *stdin*, *stdout* or *stderr* argument
+ to :class:`Popen` and indicates that the special file :data:`os.devnull`
+ will be used.
+
+ .. versionadded:: 3.3
+
+
.. data:: PIPE
Special value that can be used as the *stdin*, *stdout* or *stderr* argument