Re: [PATCH 1/2] perf tools: Ensure --symfs ends with '/'

From: Arnaldo Carvalho de Melo
Date: Fri Aug 01 2014 - 16:15:46 EST


Em Fri, Aug 01, 2014 at 08:38:02AM +0900, Namhyung Kim escreveu:
> Hi Arnaldo,
>
> On Thu, 31 Jul 2014 09:26:21 -0300, Arnaldo Carvalho de Melo wrote:
> > Em Thu, Jul 31, 2014 at 01:25:52PM +0900, Namhyung Kim escreveu:
> >> Are you still against my approach - adding '/' at the end of the symfs
> >> string itself? It seems that mine is simpler and shorter.

> > Yes, I am.

> > We are not just concatenating two strings, we are joining two path
> > components.

> > I think it is more clear and elegant to do it as python os.path.join()
> > does.

> Then I think you also need to care about trailing and leading '/' in the
> components so that, say, joining '/home/' and '/namhyung/' can result in
> '/home/namhyung/' not '/home///namhyung/'.

Well, "/home/namhyung/" is the same as "/home///namhyung/" for POSIX:
http://pubs.opengroup.org/onlinepubs/009695399/basedefs/xbd_chap03.html#tag_03_266

So, when we can easily avoid it, no use to have a sequence of slashes,
but otherwise it is harmless.

> Btw, it seems like python's os.path.join() just use latter if it's an
> absolute path.
>
> $ python
> Python 2.7.3 (default, Jul 24 2012, 10:05:38)
> [GCC 4.7.0 20120507 (Red Hat 4.7.0-5)] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
> >>> import os.path
> >>> os.path.join('/home/', '/namhyung/')
> '/namhyung/'

Interesting, wonder what is the rationale for that or if this is a bug.

- Arnaldo
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