On 27/06/07, Joerg Schilling <[EMAIL PROTECTED]> wrote:
"Shawn Walker" <[EMAIL PROTECTED]> wrote:> On 27/06/07, Joerg Schilling <[EMAIL PROTECTED]> wrote: > > "Shawn Walker" <[EMAIL PROTECTED]> wrote: > > > > > It would be possible to implement a Sun tar command-line mode would it not? > > > > > > Something like, if star is invoked as /usr/bin/tar, it would operate > > > exactly like Sun tar used to? > > > > > > Would that allow its replacement? > > > > Except for some minor differences, it already does. > > Which is why I said *exactly* :) > > So, what would it take to implement what's missing? It depends... There are undocumented features in Sun's tar. Let me give some examples: - multi volume archives. This feature from Sun tar is undocumented and it does not work well (e.g. no support for autodetecting tape size with compressing tape drives). The related archive format extension violates POSIX.1-1988 ... POSIX.1-2001 Star implements a multi volume feature (using a different but documented archive format extension - compatible to POSIX) that deals with all known problems and wishes. It may be possible to implement the Sun feature in extract mode. It makes no sense to implement it in create mode. - -@ is implemented using obsolete (and not vendor tagged) POSIX.1-1988 extensions that use a lot of quirks. This option is a big eception as it documents it's archive format! I do not like to implement this at all but rather start a discussion on how to implement support for archiving extended attribute files using clean POSIX.1-2001 based tar extensions. - -T This option omplements a completely undocumented archive format. I cannot even discuss it, except that it is also based on obsolete (and not vendor tagged) POSIX.1-1988 extensions. This list is nearly complete, there are some more undocumented features that do not live in visible options but in undocumented behavior in case of specific usage. I could look whether I find a complete list of undocumented features/behavior.
Well, I'm willing to help you implement what's missing if you're willing to move forward. I think star is a great tool, but I really think it needs to be completely compatible with sun tar as much as humanly possible. I would love to see it replace the existing tar if only because it is so much faster and provides a lot more functionality that would be useful to many users. That and it provides a GNU tar compatible mode too if I remember right. -- Shawn Walker, Software and Systems Analyst [EMAIL PROTECTED] - http://binarycrusader.blogspot.com/ "Beware of bugs in the above code; I have only proved it correct, not tried it. " --Donald Knuth _______________________________________________ opensolaris-code mailing list [email protected] http://mail.opensolaris.org/mailman/listinfo/opensolaris-code
