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zidrav(1)							     zidrav(1)

NAME
       zidrav -	detect and repair corruption in	transfered files

SYNOPSIS
       zidrav [-b bs] [-o CDT] corrupted file
       zidrav -p [-i CDT] [-o CDP] original file
       zidrav -a [-i CDP] corrupted file

DESCRIPTION
       zidrav  is  a  file  corruption detection and repair program.  It's de-
       signed to provide a way to fix file damage without having to redownload
       the entire (potentially large) file over	a (potentially	slow)  connec-
       tion.

       There are 3 steps to using zidrav (in the order of the SYNOPSIS com-
       mands):

	      1.  Create a checksum file of the	corrupted file.

	      2.  Using	the checksum file, create a patch file from the	origi-
	      nal file.

	      3.  Apply	the patch file to the corrupted	file.

       At each of the steps, the checksum or patch file	has to be in the same
       directory as the	corrupted or original file, depending on which step
       you're on, unless otherwise specified with -i.

OPTIONS
       -a     Apply the	patch file to the corrupted file in order to fix it.

       -b     Set the blocksize.  The default blocksize	it 16384.

       -h     Show usage summary and exit.

       -i     Specify  the input filename of the checksum (CDT)	or patch (CDP)
	      files.  You have to use this  flag  when	the  basename  of  the
	      checksum	or  patch files	doesn't	match the name of the original
	      file.

       -o     Specify an output	filename for the checksum (CDT)	or patch (CDP)
	      files.  By default, the name of original file  is	 used  as  the
	      basename for these files.

       -p     Build the	patch file from	the original file.

       -V     Display version information and exit.

EXAMPLE
       In  this	 example,  let's  assume  you've downloaded a large file named
       freebsd4.8.iso from a remote ftp	which you have shell access  to.   The
       file  was  corrupted  during transfer and you need to use zidrav	to fix
       the file.

       First, build a checksum file from the corrupted file on your machine:

	      zidrav freebsd4.8.iso

       This creates a checksum file named freebsd.4.8.iso.cdt.

       Next, transfer the checksum file	to the remote ftp computer in the same
       directory as the	original file.	From that directory, type:

	      zidrav -p	freebsd.4.8.iso

       This creates a patch file named freebsd.4.8.iso.cdp.

       Last, transfer the patch	file back to your computer, in the same	direc-
       tory as the corrupted file.  From that directory, type:

	      zidrav -a	freebsd.4.8.iso

       This will apply the patch and fix the corrupted file.

BUGS
       The corrupted file has to be equal in size as the original file.	  This
       makes  it  so  you  can't  fix partially	downloaded files until they're
       padded.

AUTHOR
       zidrav is written by Zorba <zorbathut@uswest.net>.  Unix	port was  done
       by  Piotr  Krukowiecki {piotr at	krukowiecki dot	net}.  This manpage by
       Cosmin Stroe <cstroe1@uic.edu>.

				 July 14, 2003			     zidrav(1)

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=zidrav&sektion=1&manpath=FreeBSD+Ports+15.0>

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