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30 .\" @(#)diff3.1 8.2 (Berkeley) 4/18/94
38 .Nd 3-way differential file comparison
42 .Op Fl Fl diff-program Ar program
43 .Op Fl Fl strip-trailing-cr
44 .Op Fl L | Fl Fl label Ar label1
45 .Op Fl L | Fl Fl label Ar label2
46 .Op Fl L | Fl Fl label Ar label3
51 utility compares the contents of three different versions of a file,
56 writing the result to the standard output.
57 The options describe different methods of merging and
59 the separate versions into a new file.
63 to merge specific versions or create
66 The options are as follows:
67 .Bl -tag -width "-E, -X"
68 .It Fl 3 , Fl Fl easy-only
69 Produces an output script suitable for
75 Treat all files as ASCII.
76 .It Fl E , Fl Fl show-overlap
82 respectively, but treat overlapping changes (i.e., changes that would
83 be noted with ==== in the normal listing) differently.
84 The overlapping lines from both files will be inserted by the edit script,
85 bracketed by "<<<<<<" and ">>>>>>" lines.
87 Produces output in a form suitable as an input script for the
90 The script may then be used to merge differences common between all
91 three files and differences specific to
97 option ignores differences specific to
101 and those specific to
105 It is useful for backing out changes specific to
112 .It Fl L , Fl Fl label
113 Defines labels to print instead of file names
118 .It Fl T, Fl Fl initial-tab
119 In the normal listing,
120 use a tab instead of two spaces
121 at the beginning of each line.
122 In modes that produce an
124 script, this option changes nothing.
125 .It Fl x, Fl Fl overlap-only
126 Produces an output script suitable for
129 specific only to all three versions.
130 .It Fl Fl diff-program Ar program
133 instead of the default
136 .It Fl Fl strip-trailing-cr
137 Strip trailing carriage return on input files.
145 to ensure that overlapping changes in the merged files are preserved
146 and brought to someone's attention.
148 For example, suppose lines 7-8 are changed in both
152 Applying the edit script generated by the command
154 .Dl $ diff3 -E file1 file2 file3
159 .Bd -literal -offset indent
172 The default output of
174 makes notation of the differences between all files, and those
175 differences specific to each pair of files.
176 The changes are described by the commands necessary for
178 to create the desired target from the different versions.
181 for a description of the commands.
182 .Bl -tag -width "====="
184 The lines beneath this notation are ranges of lines which are different
187 The lines beneath this notation are ranges of lines which are exclusively
205 option cannot catch and change lines which have
207 as the first and only character on the line.
208 The resulting script will fail on that line