>Date: Thu, 16 Aug 2007 16:47:39 -0400
>From: Glenn Fowler <gsf at research.att.com>
>Subject: Re: CIFS system attributes support for cpio(1), pax(1), tar(1) 
[PSARC/2007/459 FastTrack timeout 08/17/2007]
>
>On Thu, 16 Aug 2007 12:17:13 -0700 (PDT) Don Cragun wrote:
>> When extracting files from an archive, three ways to specify it would
>> be:
>>              pax -r -s ",^/,," -x cpio < cpio_archive
>>              pax -r -s "/^\///" -x pax < pax_archive
>>              pax -r -s "x^/xx" -x ustar < ustar_archive
>
>one minor nit,
>  "The archive formats described in the EXTENDED DESCRIPTION
>   section shall be automatically detected on input."
>so the ``-x format'' are not needed -- -x is actually not listed for the -r 
mode,
>at least at http://www.opengroup.org/onlinepubs/009695399/toc.htm
>so this would suffice
>
>       pax -r -s ",^/,," < any_archive_the_implementation_groks
>
>I believe with ``-r -x format'' an implementation may treat input archive
>mismatch as an error, but this is not explicitly stated in the standard

Glenn,
        Yes, you're correct.  Allowing -x to be used with -r is an
extension to the standard; I believe several implementations verify
that the format specified by -x is actually the format found on stdin
when both are used, but the standard is completely silent on what
happens when both -r and -x are specified on the same command line.

>
>(this *may* be the only spot in the standard where I have a chance of
> knowing something Don doesn't)

        I'm sure you know a lot more about some sections of the shell
than I do as well...

        Cheers,
        Don

>
>-- Glenn Fowler -- AT&T Research, Florham Park NJ --


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