Re: did tar(1) loose xz compression support in 11?

On Tue, 26 Aug 2014, Daniel Eischen wrote:

> On Tue, 26 Aug 2014, Tim Kientzle wrote:
>> 
>> On Aug 26, 2014, at 11:05 AM, Chris H <bsd-lists_at_bsdforge.com> wrote:
>> 
>>> Greetings,
>>> I'm currently testing 11. My build / install is from about 2 days ago.
>>> I generally use xz compression, when creating archives. But when I
>>> attempt the following:
>>> 
>>> tar -cvJ --options xz:9 -f ./archive-name.tar.xz ./file
>>> 
>>> it returns the following:
>>> 
>>> tar: Undefined option: `xz:9'
>>> 
>>> This has always worked in previous versions. Has the syntax changed,
>>> and the man(1) pages just haven't caught up?
>> 
>> I can?t see any evidence in libarchive?s source that this ever worked.
>
> The man page is a little confusing.  Here it says:
>
>  --options options
>      Select optional behaviors for particular modules.  The
>      argument is a text string containing comma-separated
>      keywords and values. These are passed to the modules that
>      handle particular formats to control how those formats will
>      behave.  Each option has one of the following forms:
>
>      key=value
>              The key will be set to the specified value in every
>              module that supports it.  Modules that do not
>              support this key will ignore it.
>
>
> Then below, after the last option, it says:
>
>      ...
>      zip:compression=type
>              Use type as compression method.  Supported values are
>              store (uncompressed) and deflate (gzip algorithm).
>
>      If a provided option is not supported by any module, that is a
>      fatal error.
>
> The first states that it is ignored, the latter states that it
> is a fatal error.  The meaning of "any module" is subtle, at
> least for my feeble brain ;-)

It suggests that options are passed to all modules, and each module is 
free to ignore options it does not understand.  But at least one module 
must understand the option, or a fatal error is reported.