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Xref: sserve comp.os.386bsd.announce:36 comp.os.386bsd.misc:236 Path: sserve!newshost.anu.edu.au!munnari.oz.au!constellation!convex!convex!darwin.sura.net!howland.reston.ans.net!agate!bounce-me From: fty@bizarre.rtpnc.epa.gov (Frank Terhaar-Yonkers) Newsgroups: comp.os.386bsd.announce,comp.os.386bsd.misc Subject: horrible hack to allow gtar to use multi-floppy compressed archives Followup-To: comp.os.386bsd.misc Date: 25 Apr 1993 16:02:09 -0700 Organization: United States Environmental Protection Agency Lines: 53 Sender: cgd@agate.berkeley.edu Approved: 386bsd-announce-request@agate.berkeley.edu Message-ID: <1993Apr21.143928.14275@rtpnc.epa.gov> NNTP-Posting-Host: agate.berkeley.edu Keywords: tar compress Compress by individual file option for GNU tar 1.11.2 This is a horrible kludge, but there's no good way to deal with compressed archives. Compressing the whole archive is too fault intolerant, don't span media (-L option) and are basically more difficult to deal with. This allows - at the expense of write performance - you to create multi-tape/floppy sets that compress individual files so that they can be dealt with like a "normal" tar archive. The header changes are backward compatible so old versions of tar can still unpack the file though they won't understand that they're compressed. Listing the archive indicates the actual size of the file and the compression program used. Compressed files can be extracted still compressed (a warning is issued) or automatically uncompressed. (note that in GNU tar 1.11.2 -z implies gzip and -Z compress) Available at: sunvis.rtpnc.epa.gov:pub/386bsd/gnu/tar-1.11.2+.tar.Z New options: --file-compress compress by individual file, uses default compression program or that specified by --use-compress-program PROG If -z or -Z is used this overrides but changes the compress program to match sense of z or Z. If extracting, file is decompressed automatically. If not specified and file is compressed, NO decompression is done and a warning is issued. As in using SPARSE files, the size reported using tv is the uncompressed size, NOT archive size. Warning! the performance is gruesome (on creates) since a tmp file must be created! (extract uses pipes). Files with .z or .Z extension or those that "grow" are not compressed. --compress-location DIRECTORY specify the directory used to create the tmp file needed by --file-compress process, default is system-default tmp location (see - man 3 tmpnam) --file-compress-size SIZE-IN-BYTES specify minimum file size eligible for --file-compress sets --file-compress automatically -- ------------------------------------------------- Frank Terhaar-Yonkers fty@vislab.rtpnc.epa.gov Martin Marietta Technical Services/U.S. EPA Research Triangle Park, North Carolina, U.S. of A (919)541-2297 -- Please send submissions for comp.os.386bsd.announce to: 386bsd-announce@agate.berkeley.edu