diff3

PURPOSE

     Compares three files.

SYNOPSIS
     diff3 [ -ex3 ] file1 file2 file3


DESCRIPTION

     The  diff3 command  reads three  versions of  a file  and
     writes to standard output the ranges of text that differ,
     flagged with the following codes:

     ====     All three files differ.
     ====1    file1 differs.
     ====2    file2 differs.
     ====3    file3 differs.

     The type of  change needed to convert a given  range of a
     given file to  match another file is indicated  in one of
     these two ways in the output:

     file  :  n1  a Text is  to be added after  line number n1
                    in file, where file is 1, 2, or 3.
     file  :  n1[,n2]  c Text in the range  line n1 to line n2
                    is to be  changed.  If n1 =  n2, the range
                    may be abbreviated to n1.

     The original  contents of  the range  follows immediately
     after a c indication.  When the contents of two files are
     identical, diff3 does not show the contents of the lower-
     numbered  file, although  it  shows the  location of  the
     identical lines for each.

     Notes:

     1.  Editing scripts produced by the -e flag cannot create
         lines consisting only of a single period (".").

     2.  The diff3 command does not  work on files longer than
         64K bytes.

FLAGS

     -e Creates an edit script for  use with the ed command to
        incorporate into  file1 all changes between  file2 and
        file3  (that is,  the changes  that normally  would be
        flagged ==== and ====3).
     -x Produces an  edit script  to incorporate  only changes
        flagged ====.
     -3 Produces an  edit script  to incorporate  only changes
        flagged ====3.

EXAMPLE

     To list the differences among three files:

       diff3  fruit.a  fruit.b  fruit.c

     If "fruit.a",  "fruit.b", and "fruit.c" contain  the fol-
     lowing data:

                    +-------------+-------------+-------------+
                    | fruit.a     | fruit.b     | fruit.c     |
                    +-------------+-------------+-------------+
                    |   banana    |   apple     |   grape     |
                    |   grape     |   banana    |   grapefruit|
                    |   kiwi      |   grapefruit|   kiwi      |
                    |   lemon     |   kiwi      |   lemon     |
                    |   mango     |   orange    |   mango     |
                    |   orange    |   peach     |   orange    |
                    |   peach     |   pear      |   peach     |
                    |   pare      |             |   pear      |
                    +-------------+-------------+-------------+

     then the output from  diff3 shows the differences between
     these files  as follows.  (The  comments on the  right do
     not appear in the output.)

     "
     ====   "o All three files are different."
     1:1,2c "   - Lines 1 and 2 of the first file, "fruit.a
       banana
       grape
     2:1,3c "   - Lines 1 through 3 of "fruit.b
       apple
       banana
       grapefruit
     3:1,2c "   - Lines 1 and 2 of "fruit.c
       grape
       grapefruit
     ====2  "o The second file, "fruit.b", is different."
     1:4,5c "   - Lines 4 and 5 are the same in "fruit.a" and "fruit.c"."
     2:4a   "   - To make "fruit.b" look the same, add text after line 4."
     3:4,5c
       lemon
       mango
     ====1  "o The first file, "fruit.a", is different."
     1:8c
       pare
     2:7c   "   - Line 7 of fruit.b and line 8 of fruit.c are the same"
     3:8c
       pear "

FILES

     /tmp/d3*
     /usr/lib/diff3prog

RELATED INFORMATION

     The following command:  "diff."