*stdin*, *stdout* and *stderr* specify the executed program's standard input,
standard output and standard error file handles, respectively. Valid values
- are :data:`PIPE`, :data:`DEVNULL`, an existing file descriptor (a positive
- integer), an existing file object with a valid file descriptor, 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 the default settings of ``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 child process should be captured into the same file
- handle as for *stdout*.
+ are ``None``, :data:`PIPE`, :data:`DEVNULL`, an existing file descriptor (a
+ positive integer), and an existing :term:`file object` with a valid file
+ descriptor. With the default settings of ``None``, no redirection will
+ occur. :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. Additionally, *stderr* can be :data:`STDOUT`, which indicates
+ that the stderr data from the child process should be captured into the same
+ file handle as for *stdout*.
.. index::
single: universal newlines; subprocess module
*stdin*, *stdout* and *stderr* specify the executed program's standard input,
standard output and standard error file handles, respectively. Valid values
- are :data:`PIPE`, :data:`DEVNULL`, an existing file descriptor (a positive
- integer), an existing :term:`file object` with a valid file descriptor,
- 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 the default settings of ``None``,
- no redirection will occur; the child's file handles will be inherited from
- the parent. Additionally, *stderr* can be :data:`STDOUT`, which indicates
+ are ``None``, :data:`PIPE`, :data:`DEVNULL`, an existing file descriptor (a
+ positive integer), and an existing :term:`file object` with a valid file
+ descriptor. With the default settings of ``None``, no redirection will
+ occur. :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. 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.
+ 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.