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Last update: 10 April,2001

                                                                1003.1-90 #49

	Classification:  No change


The standard does not speak to this issue and as such no conformance
distinction can be made between alternative implementations based on
this.

This response will be incorporated in an IEEE interpretations
publication, and will be also made available on-line on the IEEE 
SPAsystem.

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	Interpretation Number:	(to be assigned by the IEEE)
	Topic:			Extended tar format
	Relevant Sections:	10.1.1


Interpretation Request: (Defect Report)
-----------------------
POSIX.1-1990 Section 10.1.1 Extended tar Format

does not make it clear whether implementations are permitted
to store extra directories on a tar archive. For example, when
archiving "/dev/devicename", is it permissible for tar to place
an entry for "/dev" on the archive?

X/Open proposes that it is not permissible for an extra entry to
be made on the archive.  Only by explicitly specifying the directories 
should they be placed on the archive. Only by explicit specification can 
the directory permissions be recorded. Directories created in the course of
extracting from an archive will have process environment 
specified permissions if they were not explicitly put on the archive.


IEEE Interpretation for 1003.1-1990 (9945-1:1990):
--------------------------------------------------

The request addresses a point that is outside the scope of
IEEE Std 1003.1-1990.  IEEE Std 1003.1-1990 specifies the
format of tar archives, but makes no requirement of the
format-creating utility other than that it be capable
of creating conforming archives.  As long as the directory
entries in the tar archive conform to the format specified
for such entries, nothing about the behavior described
in the request is in conflict with the requirements of
IEEE Std 1003.1-1990.



Rationale for Interpretation:
-----------------------------

IEEE Std 1003.1-1990, page 169, lines 2-5:

    A conforming system shall provide a mechanism to copy files
    from a medium to the file hierarchy and copy files from the
    file hierarchy to a medium using the interchange formats
    described here.  This part of ISO/IEC 9945 does not define
    this mechanism.

The last sentence, above, specifically excludes the format-creating
utility from the scope of the Standard.  In the rationale, the
authors deferred to ISO/IEC 9945-2 (IEEE Std 1003.2-1993) for
the user interface.

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