DIFF - A file compare program

   DIFF is a program which takes  two  text  files,  and  performs  a
line-by-line comparison of them.  If more than one differing line  is
found,  DIFF considers and reports this is a single  difference.  The
'r='  parameter controls how many identical lines DIFF must  find  in
the file before it considers a difference to be ended.

   Any time a difference is found between the  files,  DIFF  displays
the line numbers indicating where the difference occurs,  followed by
the differing lines from the first file  (Preceded by  '<'),  and the
differing lines from the second file (Preceded by '>').

   The form of the DIFF command is:

                DIFF <file1> <file2> [options ...]

   The available options are:

     -d      - Inhibit display of differing lines
     -l      - Inhibit display of line numbers
     r=num   - Specify minimum # of lines to re-synchronize

   Examples:

     diff program.asm program.bak

UNDIFF - regenerate file from diffs

   UNDIFF uses the output  from  the  DIFF  command,  to  generate
another file from one.  This allows you to save  only  the  DIFF's
from one file to the next instead of saving the entire file.

   Before using UNDIFF,  you must first use DIFF to  generate  and
save a differences file:

                  DIFF file1 file2 >diffs

   Then,  you can re-generate 'file2'  using only 'file1'  and the
'diffs' file.

                 undiff file1 diffs >file2

   Undiff also has a built in compare feature,  which you can  use
to verify  that  the  regenerated  file  will  be  correct  before
deleteing the original.

                  undiff file1 diffs file2

   This above command will applys  the  'diffs'  to  'file1',  and
perform a comparison against  'file2'  reporting  any  differences
which are found.
