1.\" Copyright (c) 1990 The Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)diff3.1 6.4 (Berkeley) 07/24/90 7.\" 8.Dd 9.Dt DIFF3 1 10.Os BSD 4.3+Reno 11.Sh NAME 12.Nm diff3 13.Nd 3-way differential file comparison 14.Sh SYNOPSIS 15.Nm diff3 16.Op Fl exEX3 17.Ar file1 file2 file3 18.Sh DESCRIPTION 19The 20.Nm diff3 21utility compares the contents of three different versions of a file, 22.Ar file1 , 23.Ar file2 24and 25.Ar file3 , 26writing the result to the standard output. 27The options describe different methods of merging and 28purging 29the separate versions into a new file. 30.Nm Diff3 31is used by 32.Xr RCS 1 33to merge specific versions or create 34new versions. 35.Pp 36Options are: 37.Tp Fl e 38Produces output in a form suitable as an input script for the 39.Xr ed 1 40utility. The script may then be used to merge differences common 41between all three files and differences specific to file1 and file3. 42In other words, the 43.Fl e 44option ignores differences specific to file1 and file2, and those 45specific to file2 and file3. It is useful for backing out changes 46specific to file2 only. 47.Tp Fl x 48Produces an output script suitable for 49.Xr ed 1 50with changes 51specific only to all three versions. 52.Tp Fl 3 53Produces an output script suitable for 54.Xr ed 1 55with changes 56specific only to file3. 57.Tp Fl E , X 58Similar to 59.Fl e 60and 61.Fl x , 62respectively, but treat overlapping changes (i.e., changes that would 63be noted with ==== in the normal listing) differently. The overlapping 64lines from both files will be inserted by the edit script, bracketed 65by "<<<<<<" and ">>>>>>" lines. 66.Tp 67.Pp 68The 69.Fl E 70option is used by RCS 71.Xr merge 1 72to insure that overlapping changes in the merged files are preserved 73and brought to someone's attention. 74.Pp 75For example, suppose lines 7-8 are changed in both file1 and file2. 76Applying the edit script generated by the command 77.Pp 78.Dl diff3 -E file1 file2 file3 79.Pp 80to file1 results in the file: 81.Ds I 82lines 1-6 83of file1 84<<<<<<< file1 85lines 7-8 86of file1 87======= 88lines 7-8 89of file3 90>>>>>>> file3 91rest of file1 92.De 93.Pp 94The default output of 95.Nm diff3 96makes notation of the differences between all files, and those differences 97specific to each pair of files. The 98changes are described by 99the commands neccessary for 100.Xr ed 1 101to create the desired target from the different versions. 102See 103.Xr diff 1 104for a description of the commands. 105.Tw Fl 106.Tp Li \&==== 107The lines beneath this notation are ranges of lines which are different 108between all files. 109.Tc Li \&==== 110.Va n 111.Cx 112The lines beneath this notation are ranges of lines which are exclusively 113different in file 114.Va n . 115.Tp 116.\" .Sh EXAMPLES 117.\" .Pp 118.\" If three files were to contain: 119.\" .Ds I 120.\" .Cw mooxthree mooxthree mooxthree 121.\" .Cl file1 file2 file3 122.\" .Cl moo moo moo 123.\" .Cl moo too moon moon 124.\" .Cl moo three moo moo moo moo 125.\" .Cl tangent beam milk 126.\" .Cl moo moo sun butter 127.\" .Cl \tcloud beam 128.\" .Cl \tmoo moo 129.\" .Cl \tmoo moo 130.\" .Cw 131.\" .De 132.\" .Pp 133.\" The command line 134.\" .Pp 135.\" .Dl diff3 -e file1 file2 file3 136.\" .Pp 137.\" produces the following ed script: 138.\" .Pp 139.\" .Ds C 140.\" ====1 141.\" 1:2,4c 142.\" moo two 143.\" moo three 144.\" tangent 145.\" 2:2c 146.\" 3:2c 147.\" moon 148.\" ==== 149.\" 1:5a 150.\" 2:4,8c 151.\" beam 152.\" sun 153.\" cloud 154.\" moo moo 155.\" moo moo 156.\" 3:4,6c 157.\" milk 158.\" butter 159.\" beam 160.\" .De 161.Sh FILES 162.Dw /usr/bin/diff3 163.Di L 164.Dp Pa /tmp/d3????? 165temporary files. 166.Dp Pa /usr/bin/diff3 167the executable. 168.Dp 169.Sh SEE ALSO 170.Xr diff 1 171.Xr ed 1 172.Xr rcs 1 173.Sh HISTORY 174.Nm Diff3 175appeared in Version 7 AT&T Unix. 176.Sh BUGS 177The 178.Fl e 179option 180cannot catch and change 181lines which have 182.Sq Li \&. 183as the first ans only character on the line. 184The resulting script will fail on that line 185as the 186.Sq Li \&. 187is an 188.Xr ed 1 189editing command. 190