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 <wink/sigh>.
This commit is contained in:
Tim Peters 2002-01-30 07:47:51 +00:00
parent d9fbf353a1
commit c7349ee2c6
1 changed files with 17 additions and 1 deletions

View File

@ -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)