ucbdiff3(1)                                           ucbdiff3(1)



     NAME
          ucbdiff3 - 3-way differential file comparison

     SYNOPSIS
          ucbdiff3 [-exEX3]  file1 file2 file3

     DESCRIPTION
          ucbdiff3 is used by the rcs(1) Revision Control System.
          ucbdiff3 compares three versions of a file and publishes
          disagreeing ranges of text flagged with these codes.

          ====            all three files differ

          ====1           file1 is different

          ====2           file2 is different

          ====3           file3 is different

          The type of change suffered in converting a given range of a
          given file to some other is indicated in one of two ways.

          f:n1a           Text is to be appended after line number n1
                          in file f, where f = 1, 2, or 3.

          f:n1,n2c        Text is to be changed in the range line n1
                          to line n2.  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 identi-
          cal, the contents of the lower-numbered file is suppressed.

          Under the -e option, ucbdiff3 publishes a script for the ed-
          itor ed that will incorporate into file1 all changes between
          file2 and file3, (the changes that would normally be flagged
          ==== and ====3).  Option -x (-3) produces a script to incor-
          porate only changes flagged ==== (====3).  The following
          command will apply the resulting script to file1.

             (cat script; echo '1,$p') | ed - file1


          The -E and -X are similar to -e and -x, respectively, but
          treat overlapping changes (changes that would be flagged
          with ==== in the normal listing) differently.  The overlap-
          ping lines from both files will be inserted by the edit
          script, bracketed by <<<<<< and >>>>>> lines.

          For example, suppose lines 7-8 are changed in both f1 and
          f2.  Applying the edit script generated by the command




     April, 1990                                                     1

     ucbdiff3(1)                                           ucbdiff3(1)



             ucbdiff3 -E f1 f2 f3

          to f1 results in the file:

             lines 1-6 of f1
             <<<<<<< f1
             lines 7-8 of f1
             =======
             lines 7-8 of f3
             >>>>>>> f3
             rest of f1


          The -E option is used by RCS merge(1) to insure that over-
          lapping changes in the merged files are preserved and
          brought to someone's attention.

     FILES
          /usr/ucb/ucbdiff3
          /tmp/d3?????
          /usr/lib/ucbdiff3

     SEE ALSO
          diff(1), diff3(1), rcs(1), ucbdiff(1).

     BUGS
          Text lines that consist of a single period (.) will defeat
          -e.



























     2                                                     April, 1990