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Full Discussion: What Cinderella did - sorting the bytes
Top Forums Shell Programming and Scripting What Cinderella did - sorting the bytes Post 302148421 by fedusr on Saturday 1st of December 2007 02:25:23 PM
Old 12-01-2007
Info is nice, I didn't know Info:-)

Quote:
Originally Posted by Perderabo
...
Problem one: "/home" probably appears somewhere in the good part of the archive and your solution would then drop bytes from the archive.
Actually I applied gzip ('z' option). I have a gzip'ed archive salted by file listings at random. A gzip'ed archive is like any gzip'ed file. Tar's listings didn't flow through the gzipper, I think. I assume that the gzipped (tar) file data is in good order, but plain tar's listings are randomly spread over the gzipped file.


Quote:
Originally Posted by Perderabo
...
Problem two: The output of the listing was probably buffered because it was going to a non-tty, so blocks of lising may be interspersed and you may have lines split between blocks. So "/home/this/that" might not have fit in the buffer. So "/home/th" was put in and the buffer was written. Then "is/that{lf}" is placed in the buffer. But meanwhile output buffers of the archive are being written.
Yes, I understand. The tar listing entries are cut resp. '/home/az/...[a-Z]...<LF>' can't be applied as a kind of search string.

Quote:
Originally Posted by Perderabo
..., but I doubt that the archive can be salvaged.
On the other hand, the problem is reduced to identify the bad bytes consisting of tar's instiled file names in my messy backup file. I don't see why it should not be possible in principle. I don't know about the gzip algorithm or the gzip file format. Maybe there are checksums, byte set ranges or something like that is useful for recovery.

However, are there any compression recovery kits available (based on zlib)? I've found 'grzrecover', but it's crashing on my file:-)

Thank you.
 

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LEARN ABOUT DEBIAN

rdup-tr

RDUP-TR(1)							       rdup								RDUP-TR(1)

NAME

       rdup-tr - transform rdup output

SYNOPSIS

       rdup-tr [OPTION]...

DESCRIPTION

       Transform rdup output into something else. Where something else can be a tar, cpio, pax archive or another rdup stream.

       The rdup archive must be given on rdup-tr's standard input.

       You  can  select multiple types of output (-O flag), but you must be aware that you may loose some information in formats other than rdup's
       own, see the table below.

       You may also supply rdup-tr with only a list of pathnames, this can be selected with the -L flag.

       The following table shows what happens with the output depending on the input.

       0      OK

       D      delete information is lost

       H      hardlink information is lost

			    |		    |
		  output    | tar,cpio,pax  |  rdup
	      input	    |		    |
	      ------------- | ------------- | ------
	      rdup	    |	  D	    |	0
	      filelist	    |	  DH	    |	H
			    |		    |

OPTIONS

       -L     Select list input format. Normally rdup-tr accepts rdup output, with this option you can give it a list of path names.   Note:  with
	      list input rdup-tr will `stat()` each file.

       -O     Output format. This can be 'tar', 'cpio', 'pax' or 'rdup'. It defaults to 'rdup'.

       -X key Read  the  encryption key from the file key and encrypt all paths with Blowfish and this key and iv. After the encryption the binary
	      data is converted into ASCII using an URL safe (Section 4 of RFC 3548) version of base64 encode.

	      The encryption key must be on the first line and the key size must be 16 and 8 bytes for the iv, so 24 in total.

       -Y key Read the decryption key from the file key and decrypt all paths with Blowfish and this key. Before the encryption the paths are con-
	      verted to binary by using an URL safe version of base64 decode.

       -c     Force output to the tty. Normally rdup-tr wants to see it's output redirected.

       -v     Be more verbose.

       -V     Print rdup-tr's version.

       -h     A short help.

EXAMPLES

       The following is possible

	       rdup -Pgzip -Pmcrypt,-f,KEY,-c /dev/null /home | 
	       rdup-tr -O tar -X<(echo secret) | gzip > 
	       my-home-zipped-crypted-pathcrypted-tar.gz

       That  is:  all  files  under  /home  are  gzipped  and encrypted on a per file basis (first line). Further more, all pathnames are Blowfish
       encrypted (second line) with the key 'secret'.  This is put in a tar file, which is then compressed, resulting in the final  output  (final
       line).

       Creating a compressed and encrypted tar archive out of a full rdup dump might be done as follows

	       rdup -Pgzip -Pmcrypt,-f,KEY,-c /dev/null /home | 
	       rdup-tr -O tar > my-home-zipped-and-crypted.tar

       Or even pack and unpack it on the fly

	       rdup -Pgzip -Pmcrypt,-fKEY,-c /dev/null /home | rdup-tr -Otar | 
	       ssh user@remotehost tar xvCf /tmp -

       Or encryption with openssl

	      rdup -Popenssl,enc,-e,-des-cbc,-k,secret /dev/null /home

       Or, compressing with gzip, encrypting with openssl and then compressing the entire archive yet again

	       rdup -Pgzip -Popenssl,enc,-e,-des-cbc,-k,secret /dev/null /home | 
	       gzip > my_compressed_encrypted_rdup_archive.gz

       Recreating the original rdup output, which can be fed to rdup-up.

	       gunzip -c my_compressed_encrypted_rdup_archive.gz |
	       rdup-tr -Popenssl,enc,-d,-des-cbc,-k,secret -Pgzip,-d >
	       my_rdup_archive

	       rdup-up < my_rdup_archive -t /tmp/restore

       Notice the reversal of the -P options.

EXIT CODE

       rdup-tr return a zero exit code on success, otherwise 1 is returned.

AUTHOR

       Written by Miek Gieben.

REPORTING BUGS

       Report bugs to <miek@miek.nl>.

SEE ALSO

       http:/www.miek.nl/projects/rdup/ is the main site of rdup. Also see rdup(1), rdup-up(1) and rdup-backups(7).

COPYRIGHT

       Copyright  (C) 2005-2010 Miek Gieben. This is free software. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
       PURPOSE.

       Licensed under the GPL version 3. See the file LICENSE in the source distribution of rdup.

1.1.11								    27 Nov 2008 							RDUP-TR(1)
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