From e79c9b703117d8b0e7c4d86b704e2e7f120db883 Mon Sep 17 00:00:00 2001 From: ADITYA RAI Date: Tue, 6 Jan 2026 22:38:25 +0530 Subject: [PATCH] gh-142302: Fix mkstemp() documentation: clarify file descriptor inheritance behavior (#142338) The documentation incorrectly stated that the file descriptor is not inherited by child processes. In reality, the close-on-exec flag (when available) only prevents inheritance across exec() calls, not fork(). Co-authored-by: Victor Stinner --- Doc/library/os.rst | 3 ++- Doc/library/tempfile.rst | 5 +++-- 2 files changed, 5 insertions(+), 3 deletions(-) diff --git a/Doc/library/os.rst b/Doc/library/os.rst index 9a9b79e7906c..c766aa4afc8a 100644 --- a/Doc/library/os.rst +++ b/Doc/library/os.rst @@ -1979,7 +1979,8 @@ can be inherited by child processes. Since Python 3.4, file descriptors created by Python are non-inheritable by default. On UNIX, non-inheritable file descriptors are closed in child processes at the -execution of a new program, other file descriptors are inherited. +execution of a new program, other file descriptors are inherited. Note that +non-inheritable file descriptors are still *inherited* by child processes on :func:`os.fork`. On Windows, non-inheritable handles and file descriptors are closed in child processes, except for standard streams (file descriptors 0, 1 and 2: stdin, stdout diff --git a/Doc/library/tempfile.rst b/Doc/library/tempfile.rst index f0a81a093b43..9d26f47820b1 100644 --- a/Doc/library/tempfile.rst +++ b/Doc/library/tempfile.rst @@ -225,8 +225,9 @@ The module defines the following user-callable items: properly implements the :const:`os.O_EXCL` flag for :func:`os.open`. The file is readable and writable only by the creating user ID. If the platform uses permission bits to indicate whether a file is executable, - the file is executable by no one. The file descriptor is not inherited - by child processes. + the file is executable by no one. + + The file descriptor is :ref:`not inherited by child processes `. Unlike :func:`TemporaryFile`, the user of :func:`mkstemp` is responsible for deleting the temporary file when done with it. -- 2.47.3