Re: tar-pax or tar-ustar as a default for automake

[Andrew W. Nosenko]

On Thu, Jun 23, 2011 at 16:59, Bob Friesenhahn
 wrote:
> On Thu, 23 Jun 2011, Andrew W. Nosenko wrote:
>>
>> Hmmm...  What about do not enforce any particular format by default?
>> Especially if consider that on my FreeBSD automake already enforses
>> ustar when tries to enforce v7 ;-)
>>
>>   tardir=testprog-0.0.0 && /usr/local/bin/bash
>> /home/user/tmp/testprog/missing --run tar chof - "$tardir" | bzip2 -9
>> -c >testprog-0.0.0.tar.bz2
>>
>> The 'o' option in the 'tar chof -' above means '-‐format ustar' for
>> bsdtar instead of '--format v7' for GNU tar :-)
>
> That is very interesting.  On my Solaris system, I see that the 'gtar'
> program was selected.  With this 'gtar' the -o option is equivalent to:
>
>      --old-archive, --portability
>                             same as --format=v7
>
> but I see that with bsdtar -o requests a different format:
>
>     -o      (c, r, u mode) A synonym for --format ustar
>

On FreeBSD tar (/usr/bin/tar) is bsdtar.
When automake targets v7 format, it doesn't do any checks, just
defaults to "missing --run tar chof - "$tardir"" and relies on
'missing' script to workaround if something goes not properly (i.e. if
strioghtforward invocation of "tar chof -" won't work).
But tar (bsdtar) know about -o, creates tarfile, returns success, etc.
 Just means under '-o' not the same, as caller :-)

-- 
Andrew W. Nosenko 

Re: tar-pax or tar-ustar as a default for automake

[Bob Friesenhahn]

On Thu, 23 Jun 2011, Andrew W. Nosenko wrote:


Hmmm...  What about do not enforce any particular format by default?
Especially if consider that on my FreeBSD automake already enforses
ustar when tries to enforce v7 ;-)

   tardir=testprog-0.0.0 && /usr/local/bin/bash
/home/user/tmp/testprog/missing --run tar chof - "$tardir" | bzip2 -9
-c >testprog-0.0.0.tar.bz2

The 'o' option in the 'tar chof -' above means '-‐format ustar' for
bsdtar instead of '--format v7' for GNU tar :-)


That is very interesting.  On my Solaris system, I see that the 'gtar' 
program was selected.  With this 'gtar' the -o option is equivalent 
to:


  --old-archive, --portability
 same as --format=v7

but I see that with bsdtar -o requests a different format:

 -o  (c, r, u mode) A synonym for --format ustar

Bob
--
Bob Friesenhahn
bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,http://www.GraphicsMagick.org/

Re: tar-pax or tar-ustar as a default for automake

[Andrew W. Nosenko]

2011/6/23 Bob Friesenhahn :
> On Wed, 22 Jun 2011, Javier Jardón wrote:
>>
>> FYI, GNU tar added pax support in 2004 [1]
>> Anyway, a change to ustar would be enough for us. Should I file a bug for
>> this?
>
> Filing a bug sounds like a good idea.  The issue is less likely to be
> forgotten.
>

Hmmm...  What about do not enforce any particular format by default?
Especially if consider that on my FreeBSD automake already enforses
ustar when tries to enforce v7 ;-)

tardir=testprog-0.0.0 && /usr/local/bin/bash
/home/user/tmp/testprog/missing --run tar chof - "$tardir" | bzip2 -9
-c >testprog-0.0.0.tar.bz2

The 'o' option in the 'tar chof -' above means '-‐format ustar' for
bsdtar instead of '--format v7' for GNU tar :-)

-- 
Andrew W. Nosenko 

Re: tar-pax or tar-ustar as a default for automake

[Bob Friesenhahn]

On Wed, 22 Jun 2011, Javier Jardón wrote:


FYI, GNU tar added pax support in 2004 [1]
Anyway, a change to ustar would be enough for us. Should I file a bug for this?


Filing a bug sounds like a good idea.  The issue is less likely to be 
forgotten.


Bob
--
Bob Friesenhahn
bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,http://www.GraphicsMagick.org/

Re: tar-pax or tar-ustar as a default for automake

[Javier Jardón]

On 22 June 2011 02:28, Bob Friesenhahn  wrote:
> On Tue, 21 Jun 2011, Russ Allbery wrote:
>>
>> The problem, of course, being that pax probably isn't available, which
>> makes it hard for a default choice.
>
> As per WikiPedia:
>
> "Despite being standardized in 2001 by IEEE, as of 2010, pax enjoys
> relatively little popularity and penetration rate.
>
> pax is required to be present in all conformant systems by Linux Standard
> Base since version 3.0 (released on July 6, 2005),[2] but so far few Linux
> distributions ship and install it by default. However, most distributions
> include pax as a separately installable package."
>
> I find pax under Solaris, FreeBSD, & Apple's OS X but not (by default on)
> Ubtuntu Linux.

FYI, GNU tar added pax support in 2004 [1]
Anyway, a change to ustar would be enough for us. Should I file a bug for this?

Best regards


[1] http://en.wikipedia.org/wiki/Tar_(file_format) (See problems and
limitations)
-- 
Javier Jardón Cabezas

Re: tar-pax or tar-ustar as a default for automake

[Russ Allbery]

Bob Friesenhahn  writes:

> pax is required to be present in all conformant systems by Linux
> Standard Base since version 3.0 (released on July 6, 2005),[2] but so
> far few Linux distributions ship and install it by default. However,
> most distributions include pax as a separately installable package."

> I find pax under Solaris, FreeBSD, & Apple's OS X but not (by default on)
> Ubtuntu Linux.

Ah, it might be more widespread than I thought.  It seems to be on RHEL 5
as well (although I'm not sure what level of install you need).

It's packaged for Debian, of course, but isn't part of a typical install.

-- 
Russ Allbery (r...@stanford.edu) 

Re: tar-pax or tar-ustar as a default for automake

[Bob Friesenhahn]

On Tue, 21 Jun 2011, Russ Allbery wrote:


The problem, of course, being that pax probably isn't available, which
makes it hard for a default choice.


As per WikiPedia:

"Despite being standardized in 2001 by IEEE, as of 2010, pax enjoys 
relatively little popularity and penetration rate.


pax is required to be present in all conformant systems by Linux 
Standard Base since version 3.0 (released on July 6, 2005),[2] but so 
far few Linux distributions ship and install it by default. However, 
most distributions include pax as a separately installable package."


I find pax under Solaris, FreeBSD, & Apple's OS X but not (by default 
on) Ubtuntu Linux.


Bob
--
Bob Friesenhahn
bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,http://www.GraphicsMagick.org/

Re: tar-pax or tar-ustar as a default for automake

[Russ Allbery]

Bob Friesenhahn  writes:

> Does automake depend on 'tar' being GNU tar?  If it will use any old
> tar, then one would assume that it uses the default output format since
> otherwise it might not know how to request some other format variant.
> If it it used 'pax' then the output format can be certain.

The problem, of course, being that pax probably isn't available, which
makes it hard for a default choice.

-- 
Russ Allbery (r...@stanford.edu) 

Re: tar-pax or tar-ustar as a default for automake

[Bob Friesenhahn]

On Tue, 21 Jun 2011, Javier Jardón wrote:


I'd like to know if there is a plan to switch to tar-pax or tar-ustar
(seems that pax support is broken in openbsd) as a default tar format.
Currently we have some problem in GNOME project with some modules
because the limitations of the current tar format
I'd like to know if would be possible a change in the default so we
dont have to patch all the GNOME modules


Does automake depend on 'tar' being GNU tar?  If it will use any old 
tar, then one would assume that it uses the default output format 
since otherwise it might not know how to request some other format 
variant.  If it it used 'pax' then the output format can be certain.


Given the amount of time which has elapsed, trying to obtain at least 
'ustar' format (from POSIX.1-1988) seems quite reasonable.


Bob
--
Bob Friesenhahn
bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer,http://www.GraphicsMagick.org/