xdelta - Invoke XDelta


SYNOPSIS

       xdelta subcommand [ option...  ] [ operand...  ]


DESCRIPTION

       XDelta  provides  the ability to generate deltas between a
       pair of files and later apply those deltas.   It  operates
       similar  to  the  diff  and  patch  commands, but works on
       binary files and does not produce a human readable output.

       XDelta  has  two  subcommands,  delta  and  patch.   Delta
       accepts two  files  and  produces  a  delta,  while  patch
       accepts  one  original  file  and a delta and produces the
       other file.  As opposed to the the diff(1)  format,  which
       can usually be reversed, these deltas are one way.

   Subcommands
       Each  subcommand will be detailed seperately.  In general,
       any input file may be compressed with gzip(1)  and  XDelta
       will automatically uncompress it into a temporary location
       before examining the file.   This  temporary  location  is
       either  the  value of the environment variable, if set, or
       "/tmp".  Unless turned off,  XDelta  always  verifies  the
       integrity  of  reconstructed files with MD5 checksums.  By
       default, XDelta compresses constructed  deltas,  but  this
       feature may be turned off.

   Delta
       The delta subcommand has the following synopsis:

       xdelta delta [ option...  ] from to [ patch ]

       Computes a delta from from to to and writes it to patch or
       the standard output if patch is omitted or is named "-".

   Patch
       The patch subcommand has the following synopsis:

       xdelta patch [ option...  ] patch [ from [ to ]]

       Applies patch  to  from.   If  from  was  omitted,  XDelta
       attempts to use the file with the original from file name.
       The from file must be identical to the one used to  create
       the delta.  Its MD5 checksum is used to verify this condi­
       tion.  The constructed file will be written to  to  unless
       to  is  named  "-"  or  the original to file name if to is
       omitted.

       -0..9  Set the zlib compression level.  Zero indicates  no
              compression.  Nine indicates maximum compression.

       -h     Print a short help message and exit.

       -v     Print the XDelta version number and exit.

       -V     Verbose.  Prints a bit of extra information.

       -n     No  verify.  Turns off MD5 checksum verification of
              the input and output files.

       -m=size
              Set an upper bound on the size of an in-memory page
              cache.


IDENTIFICATION

       Author: Josh MacDonald
       Manual  Page Revision: 1.2; Release Date: Fri, 09 Apr 1999
       15:25:54 -0700.
       Copyright © 1997, 1998


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