On Fri, 2009-08-07 at 13:14 +0200, Christian Maeder wrote: > Christian Maeder wrote: > > Matthias Kilian wrote: > >> However, to create an archive, you can use something like > >> > >> $ pax -wf foo.tar directory > > > > Do you think "gtar --format=posix" would be different from pax?
I would expect they are the same. The USTAR format is standardised by a POSIX standard from 1988 while the pax extensions are standardised by POSIX from 2001 I think. The pax program has an -x format flag and can use pax, ustar or cpio formats. The pax format is an extension of the ustar format. > > The only question is, if we should create archives using the ustar, > > posix/pax, or gnu format. ustar seems to be the least common > > denominator. Does ustar have any disadvantages? For source code distribution I think the ustar format is ideal. This is what cabal-install's sdist mode uses. As you say it's the lowest common denominator. The limitations of the format (file sizes, lack of extended file meta-data) are not a practical problem for source code or binaries. > My plain tar command under solaris cannot handle the pax files, too. > So ustar archives should be created (at least under solaris). That's odd since pax is supposed to be a compatible extension of ustar that just adds extra meta-data entries. Older programs should either ignore those entries or extract them as if they were ordinary files. > But I don't know why the ustar format can handle long file names, The ustar format can handle file names up to 100+155 characters (bytes) long. The reason for 100+155 is that it's not simply 255. The split into a 100 and 155 field must happen on a directory separator. > whereas the gnu format creates a "@LongLink" file and pax a "PaxHeader" > file (when unpacked with tar). Right, those "files" are the extended entries. Duncan _______________________________________________ Glasgow-haskell-users mailing list [email protected] http://www.haskell.org/mailman/listinfo/glasgow-haskell-users
