Documentation of os.exec*() provides confusing information about "flushing file descriptors"

Documentation

The documentation of os.exec*() says:

The current process is replaced immediately. Open file objects and descriptors are not flushed, so if there may be data buffered on these open files, you should flush them using sys.stdout.flush() or os.fsync() before calling an exec* function.

However, os.fsync() flushs OS buffers to disk, and has nothing to with flushing userspace buffer to OS.

Linked PRs

• gh-133333

從 issue 中引用的 os.exec*() 文件開始，比較 sys.stdout.flush() 與 os.fsync() 的作用。確認措辭準確地區分了使用者空間緩衝與 OS 緩衝，然後驗證修訂後的文件是否清楚說明在 exec*() 之前應該 flush 什麼。