4.3BSD-Reno/share/man/cat1/diff3.0

DIFF3(1)		    UNIX Reference Manual		      DIFF3(1)

NNAAMMEE
     ddiiffff33 - 3-way differential file comparison

SSYYNNOOPPSSIISS
     ddiiffff33 [--eexxEEXX33] _f_i_l_e_1 _f_i_l_e_2 _f_i_l_e_3

DDEESSCCRRIIPPTTIIOONN
     The ddiiffff33 utility compares the contents of three different versions of a
     file, _f_i_l_e_1, _f_i_l_e_2 and _f_i_l_e_3, writing the result to the standard output.
     The options describe different methods of merging and purging the
     separate versions into a new file.  DDiiffff33 is used by RCS(1) to merge
     specific versions or create new versions.

     Options are:

     --ee        Produces output in a form suitable as an input script for the
	       ed(1) utility.  The script may then be used to merge differ-
	       ences common between all three files and differences specific
	       to file1 and file3.  In other words, the --ee option ignores
	       differences specific to file1 and file2, and those specific to
	       file2 and file3.  It is useful for backing out changes specific
	       to file2 only.

     --xx        Produces an output script suitable for ed(1) with changes
	       specific only to all three versions.

     --33        Produces an output script suitable for ed(1) with changes
	       specific only to file3.

     --EE, --XX    Similar to --ee and --xx, respectively, but treat overlapping
	       changes (i.e., changes that would be noted with ==== in the
	       normal listing) differently.  The overlapping lines from both
	       files will be inserted by the edit script, bracketed by
	       "<<<<<<" and ">>>>>>" lines.

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

     For example, suppose lines 7-8 are changed in both file1 and file2.  Ap-
     plying the edit script generated by the command

	   diff3 -E file1 file2 file3

     to file1 results in the file:
	   lines 1-6
	   of file1
	   <<<<<<< file1
	   lines 7-8
	   of file1
	   =======
	   lines 7-8
	   of file3
	   >>>>>>> file3
	   rest of file1

     The default output of ddiiffff33 makes notation of the differences between all
     files, and those differences specific to each pair of files. The changes
     are described by the commands neccessary for ed(1) to create the desired
     target from the different versions.  See diff(1) for a description of the
     commands.

     ====      The lines beneath this notation are ranges of lines which are
	       different between all files.

     ====_n     The lines beneath this notation are ranges of lines which are
	       exclusively different in file _n.

FFIILLEESS
     /_t_m_p/_d_3?????     temporary files.
     /_u_s_r/_b_i_n/_d_i_f_f_3   the executable.


SSEEEE AALLSSOO
     diff(1) ed(1) rcs(1)

HHIISSTTOORRYY
     DDiiffff33 appeared in Version 7 AT&T Unix.

BBUUGGSS
     The --ee option cannot catch and change lines which have `.' as the first
     ans only character on the line.  The resulting script will fail on that
     line as the `.' is an ed(1) editing command.