Re: [Bug-tar] RFE? tar doesn't copy file attributes or ACL's (full permissions)
Linda A. Walsh wrote: Would it be possible to get tar to copy (or ignore) file attributes, and to copy ACL's if they exist ( maybe via an option)? There's been a little work on this over the last few years. The native tar programs for Solaris and AIX provide some of this, but obviously only for their particular platforms. As far as I know, Joerg Schilling's "star" was one of the first to provide this using the extension mechanism of the standard "pax extended" format. Joerg did a pretty good job; bsdtar and GNU tar have each implemented some of this compatibly with "star." Unfortunately, the "star" extensions only support POSIX.1e-style ACLs which are quite a bit different from the Windows-style ACLs (also called "NTFS" or "NFS4" ACLs). I know Joerg was working to extend it to support NTFS/NFS4 ACLs but haven't heard whether he ever finished that. That said, Joerg's work to support POSIX.1e ACLs is well worth studying. In particular, Joerg worked out one important issue that both the Solaris and AIX implementations got wrong: Joerg included both names and numeric IDs for every account referenced in an ACL. A lot of people are interested in this, but it's a matter of someone sufficiently knowledgeable about the issues actually doing the work. I've done some research and written up some of my findings to help anyone who would like to tackle this: http://code.google.com/p/libarchive/wiki/TarNFS4ACLs Cheers, Tim Kientzle
[Bug-tar] RFE? tar doesn't copy file attributes or ACL's (full permissions)
Had a 'feature deficit' that I thought of for tar...;^) Would it be possible to get tar to copy (or ignore) file attributes, and to copy ACL's if they exist ( maybe via an option)? Some attr's I really like to keep on files, and end up having to use something a host of different utils (depending on fs and os), but common examples are the '+d" 'don't dump' attribute -- something I usually set on large multi-gig scratch files I'm using for testing, or temporary copies of DVD's on my disk (certainly don't need to back up such things as the original is the DVD -- much better than trying to use backup space). ACL's -- those would be most useful for me under Cygin-Windows. Cygwin uses Windows ACL's itself for emulating the standard unix rwx permisions for groups, but native ACL's are also set for existing files that it would be nice if they could be kept in a backup. (Since Window's native backup seems to die about 165G into its backup attempt (I think it is actually 'finished', and dies during final 'housekeeping'). I'd rather save it in a standard format if I could (i.e. tar)... Of course on Win, it has underlying file attribs as well, (HSRA...) Dunno how possible...but certainly the ext2+xfs 'd' attribs and file ACLS's -- it'd be up to the support libraries to actually be available to be able to pull the values in so 'tar' could store them. _Maybe_ for Backwards compat such info could be stored ahead of a file in some variation of the filename? Like if fn="filename", then store attribs in .filename#.%attrib%., if need to avoid fn collisions? Just a thought...? Linda
