RE: Automake security problem

[Bernard Dautrevaux <Dautrevaux at microprocess dot com>]

> -----Original Message-----
> From: Jim Meyering [mailto:meyering@ascend.com]
> Sent: Thursday, March 02, 2000 10:11 PM
> To: Alexandre Oliva
> Cc: Bob Friesenhahn; automake@gnu.org
> Subject: Re: Automake security problem
> 
> 
> Alexandre Oliva <oliva@lsd.ic.unicamp.br> writes:
> | On Mar  2, 2000, Jim Meyering <meyering@ascend.com> wrote:
> | > That'd be ok if there were a compelling reason to 
> continue using such
> | > hacks, but in any case, please don't advocate use of 
> -exec in cases
> | > like this.  Using xargs is more efficient:
> |
> | But xargs is not as portable: it's not available on all 
> platforms, it
> | may fail if there are too many too long pathnames, and it may find
> | trouble with filenames containing blanks (but, admittedly, so would
> | make and automake), so I just played on the safe side.
> 
> Your arguments don't hold water.
> As you know, this is for the `make dist' rule.  I consider that
> to be one of those rules that should work well for a *maintainer*,
> not necessarily for the average user.  If a maintainer doesn't have
> a working version of xargs, then they should install it.  Similarly,
> if someone builds a distribution for which `find|xargs 
> whatever' fails,
> then they have much larger problems.  We should compromise quality
> only when necessary.

I think I will agree on this; anyway I don't see any system where I don't
have a working xargs for quite a long time...

> 
> I'm not aware of any way in which `too many too long pathnames' can
> cause problems with xargs.  Would you please elaborate?
> Even with GNU xargs?
> 

This problem is NOT with xargs; it's with the generated command line (which
is usually limited to 10240 characters by the underlying system). Hopefully
the solution IS in xargs: just use for example "find <something> | xargs
-n10 <whatever you need to do>", and you should have path names of
consistently more than 1024 characters to have any problem (I persoinally
have -n64 wired in my fingers...) but you get a 10-times increase in speed
WRT -exec in find :-)


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Bernard Dautrevaux
Microprocess Ingéniérie
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e-mail:	dautrevaux@microprocess.com
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