renaming an open file in nt like unix?

[aaron.watters]

Hi. I'm writing an archival system which I'd like to be portable
to Windows.

The system relies on the property of Unix which allows a
process to keep a file open even if another process renames
it while it is open. Neither process sees any anomaly or
error.

Do the NT file systems support this feature (which I think is
standard for POSIX systems)?

Inquiring minds want to know. -- Aaron Watters

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will keep 3 doctors away. -- kliban

 

[Thomas Heller]

Hi. I'm writing an archival system which I'd like to be portable
to Windows.

The system relies on the property of Unix which allows a
process to keep a file open even if another process renames
it while it is open. Neither process sees any anomaly or
error.

Do the NT file systems support this feature (which I think is
standard for POSIX systems)?

Yes, you can do that. We implemented something like this to replace
dlls there are currently in use - rename the currently open file, create a new one
with the old name (newly started processes will use the new one then),
and delete the renamed one at the next possible occasion (usually at
the next reboot). I'm not so sure on which NT versions it works this
way, at least in w2000 and newer.

Thomas

 

[Steve Holden]

Yes, you can do that. We implemented something like this to replace
dlls there are currently in use - rename the currently open file, create a new one
with the old name (newly started processes will use the new one then),
and delete the renamed one at the next possible occasion (usually at
the next reboot). I'm not so sure on which NT versions it works this
way, at least in w2000 and newer.

Thomas

You do have to be careful though, because sometimes Windows refuses to
let you rename a file because it's in use.

regards
Steve
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[aaron.watters]

(e-mail address removed) schrieb:=

...Do the NT file systems support [renaming an open file] (which I think is
standard for POSIX systems)?

Yes, you can do that. We implemented something like this to replace
dlls there are currently in use...

You do have to be careful though, because sometimes Windows refuses to
let you rename a file because it's in use.

At least on my laptop I see Steve's behaviour. fwiw:

C:\Documents and Settings\aaron\Desktop>opentest.py rename
rename sleeps 1
renamer sleeping 5
now renaming
Traceback (most recent call last):
File "C:\Documents and Settings\aaron\Desktop\opentest.py", line 69,
in <modul
e>
renameProcess()
File "C:\Documents and Settings\aaron\Desktop\opentest.py", line 31,
in rename
Process
os.rename(firstname, secondname)
WindowsError: [Error 13] The process cannot access the file because it
is being
used by another process

So it looks like the answer in general is "no: you can't do that
on Windows."

Drat! Foiled again.
-- Aaron Watters

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