From c7349ee2c6863263eef4d48ee19f741e6d2244be Mon Sep 17 00:00:00 2001 From: Tim Peters Date: Wed, 30 Jan 2002 07:47:51 +0000 Subject: [PATCH] New TemporaryFile implementation for Windows: this doesn't need a TemproraryFileWrapper wrapper anymore, and should be immune from the problem that a temp file inherited by a spawned process caused an attempt to close the temp file in the spawning process to blow up (the unlink in TemporaryFileWrapper.close() blew up with a "Permission denied" error because, despite that the temp file got closed in the spawning process, the spawned process still had it open by virtue of C-level file descriptor inheritance). In context, that bug took days to figure out . --- Lib/tempfile.py | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/Lib/tempfile.py b/Lib/tempfile.py index 51e43b0e0ed..99177f539f1 100644 --- a/Lib/tempfile.py +++ b/Lib/tempfile.py @@ -193,8 +193,24 @@ def TemporaryFile(mode='w+b', bufsize=-1, suffix=""): except: os.close(fd) raise + elif os.name == 'nt': + # Windows -- can't unlink an open file, but O_TEMPORARY creates a + # file that "deletes itself" when the last handle is closed. + # O_NOINHERIT ensures processes created via spawn() don't get a + # handle to this too. That would be a security hole, and, on my + # Win98SE box, when an O_TEMPORARY file is inherited by a spawned + # process, the fd in the spawned process seems to lack the + # O_TEMPORARY flag, so the file doesn't go away by magic then if the + # spawning process closes it first. + flags = (os.O_RDWR | os.O_CREAT | os.O_EXCL | + os.O_TEMPORARY | os.O_NOINHERIT) + if 'b' in mode: + flags |= os.O_BINARY + fd = os.open(name, flags, 0700) + return os.fdopen(fd, mode, bufsize) else: - # Non-unix -- can't unlink file that's still open, use wrapper + # Assume we can't unlink a file that's still open, or arrange for + # an automagically self-deleting file -- use wrapper. file = open(name, mode, bufsize) return TemporaryFileWrapper(file, name)