From: Ryan Johnson <ryan.johnson@cs.utoronto.ca>
To: cygwin@cygwin.com
Subject: Re: stat() and tilde prefix (was bad bash tab completion)
Date: Mon, 14 Jan 2013 21:37:00 -0000 [thread overview]
Message-ID: <50F47A8B.5050001@cs.utoronto.ca> (raw)
In-Reply-To: <c040ca2ce35648f99318ee341647c241@BN1PR03MB087.namprd03.prod.outlook.com>
On 14/01/2013 3:24 PM, Stephan Mueller wrote:
> Perhaps (as you may well have already considered):
>
> - replace the path prefix by the mount point first? (this may be naïve
> on my part, but it's not clear to me that .. early in a path should be able
> to influence which mount point is substituted)
If I mount something at /foo/bar/baz, then /foo/bar/baz/../../blah
definitely shouldn't end up inside baz.
> - test directory existence of the component preceding .. before collapsing
> (in the example above) b/.. to nothing.
> - trust that for a/b3/b2/b/../../../c, the existence test of a/b3/b2/b
> before collapsing b/.. to nothing implies existence of b2 and b3 so no
> further tests are needed for 'runs' of .. components with enough
> components before them
>
> Understood that this is still going to cause a slowdown because paths with
> .. are not uncommon, but it would reduce the number of additional
> existence checks from one-per-path-component to one-per-run-of-..,
> which means none in the case of paths without .. in them.
The rest seems totally reasonable to me, FWIW.
I wouldn't put it past a Makefile (esp. one generated by autotools) or a
gcc header search path to generate paths like:
/a/b/c/d/../e/../f/../../../g/h (which resolves to a/g/h, if I counted
dots correctly). Even then, though, it's "only" three checks to achieve
posix-compliant behavior.
Ryan
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next prev parent reply other threads:[~2013-01-14 21:37 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-10 14:25 bad bash tab completion Shaddy Baddah
2012-08-10 16:54 ` Eric Blake
2013-01-14 5:21 ` stat() and tilde prefix (was bad bash tab completion) Shaddy Baddah
2013-01-14 6:17 ` Christopher Faylor
2013-01-14 12:23 ` Corinna Vinschen
2013-01-14 14:37 ` Shaddy Baddah
2013-01-14 16:13 ` Corinna Vinschen
2013-01-14 20:29 ` Stephan Mueller
2013-01-14 21:37 ` Ryan Johnson [this message]
2013-01-15 8:44 ` Corinna Vinschen
2013-01-15 12:33 ` Shaddy Baddah
2013-02-07 7:00 ` Shaddy Baddah
2013-02-07 15:32 ` Eric Blake
2013-02-07 16:10 ` Thomas Wolff
2013-02-07 16:24 ` Corinna Vinschen
2013-02-07 16:26 ` Christopher Faylor
2013-01-14 15:27 ` Christopher Faylor
2013-01-14 16:05 ` Corinna Vinschen
2013-01-14 17:00 ` Christopher Faylor
2013-01-14 22:15 ` Thomas Wolff
2013-01-15 8:56 ` Corinna Vinschen
2013-01-15 19:50 ` Andrey Repin
2013-01-15 20:03 ` Larry Hall (Cygwin)
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