Bugtraq mailing list archives
Re: Changes to the filesystem while find is running - comments?
From: devnull () Rodents Montreal QC CA
Date: Wed, 24 Nov 2004 00:24:57 -0500 (EST)
(Because I'm so sick of the broken autoresponders bugtraq is full of, I've set the From: on this mail to a black-hole address. Please use the address in the signature if you actually want to reach me.)
Before a chdir to "foo", take stock: - record stat("."); DOTFD = open("."); (get a fd to ".")
This is not possible if . is a search-only directory. (While find will not work very well in such a directory, care should be taken that it not fall over just because someone happened to chmod the read bits away from a directory just when find happens to be in it.) More generally, I've wanted to do this - use file descriptors as handles onto directories - and often wished for an O_NOACCESS mode to open() in consequence.
Of course, open(2) will follow a symlink, if the directory we originally stat()ed is replaced by a symlink just before we issue the open() call. We of course can guard against that by issuing an lstat() on the fd once we have opened it.
ITYPM fstat(), not lstat(), in the last line. /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse () rodents montreal qc ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
Current thread:
- Changes to the filesystem while find is running - comments? James Youngman (Nov 22)
- Re: Changes to the filesystem while find is running - comments? Martin Buchholz (Nov 22)
- Re: Changes to the filesystem while find is running - comments? Dmitry V. Levin (Nov 22)
- Re: Changes to the filesystem while find is running - comments? James Youngman (Nov 23)
- Re: Changes to the filesystem while find is running - comments? Martin Buchholz (Nov 23)
- Re: Changes to the filesystem while find is running - comments? James Youngman (Nov 23)
- Re: Changes to the filesystem while find is running - comments? Martin Buchholz (Nov 23)
- Re: Changes to the filesystem while find is running - comments? devnull (Nov 24)
- Re: Changes to the filesystem while find is running - comments? Casper . Dik (Nov 24)
- Re: Changes to the filesystem while find is running - comments? Martin Buchholz (Nov 24)
- Re: Changes to the filesystem while find is running - comments? Casper . Dik (Nov 24)
- Re: Changes to the filesystem while find is running - comments? Martin Buchholz (Nov 22)
- Re: Changes to the filesystem while find is running - comments? James Youngman (Nov 25)
- <Possible follow-ups>
- Re: Changes to the filesystem while find is running - comments? Paul Szabo (Nov 23)
- Re: Changes to the filesystem while find is running - comments? James Youngman (Nov 23)
- Re: Changes to the filesystem while find is running - comments? Paul Szabo (Nov 23)
- Re: Changes to the filesystem while find is running - comments? Martin Buchholz (Nov 23)
- Re: Changes to the filesystem while find is running - comments? Paul Szabo (Nov 23)
- Re: Changes to the filesystem while find is running - comments? James Youngman (Nov 23)