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.TH MERGE 1 \*(Dt GNU
.SH NAME
merge \- three-way file merge
.SH SYNOPSIS
.B merge
[
.I "options"
]
.I "file1 file2 file3"
.SH DESCRIPTION
.B merge
incorporates all changes that lead from
.I file2
to
.I file3
into
.IR file1 .
The result ordinarily goes into
.IR file1 .
.B merge
is useful for combining separate changes to an original.  Suppose
.I file2
is the original, and both
.I file1
and
.I file3
are modifications of
.IR file2 .
Then
.B merge
combines both changes.
.PP
A conflict occurs if both
.I file1
and
.I file3
have changes in a common segment of lines.
If a conflict is found,
.B merge
normally outputs a warning and brackets the conflict with
.B <<<<<<<
and
.B >>>>>>>
lines.
A typical conflict will look like this:
.LP
.RS
.nf
.BI <<<<<<< " file A"
.I "lines in file A"
.B "======="
.I "lines in file B"
.BI >>>>>>> " file B"
.RE
.fi
.LP
If there are conflicts, the user should edit the result and delete one of the
alternatives.
.SH OPTIONS
.TP
.B \-A
Output conflicts using the
.B \-A
style of
.BR diff3 (1),
if supported by
.BR diff3 .
This merges all changes leading from
.I file2
to
.I file3
into
.IR file1 ,
and generates the most verbose output.
.TP
\f3\-E\fP, \f3\-e\fP
These options specify conflict styles that generate less information
than
.BR \-A .
See
.BR diff3 (1)
for details.
The default is
.BR \-E .
With
.BR \-e ,
.B merge
does not warn about conflicts.
.TP
.BI \-L " label"
This option may be given up to three times, and specifies labels
to be used in place of the corresponding file names in conflict reports.
That is,
.B "merge\ \-L\ x\ \-L\ y\ \-L\ z\ a\ b\ c"
generates output that looks like it came from files
.BR x ,
.B y
and
.B z
instead of from files
.BR a ,
.B b
and
.BR c .
.TP
.BI \-p
Send results to standard output instead of overwriting
.IR file1 .
.TP
.BI \-q
Quiet; do not warn about conflicts.
.TP
.BI \-V
Print \*r's version number.
.SH DIAGNOSTICS
Exit status is 0 for no conflicts, 1 for some conflicts, 2 for trouble.
.SH IDENTIFICATION
Author: Walter F. Tichy.
.br
Manual Page Revision: \*(Rv; Release Date: \*(Dt.
.br
Copyright \(co 1982, 1988, 1989 Walter F. Tichy.
.br
Copyright \(co 1990, 1991, 1992, 1993, 1994, 1995 Paul Eggert.
.SH SEE ALSO
diff3(1), diff(1), rcsmerge(1), co(1).
.SH BUGS
It normally does not make sense to merge binary files as if they were text, but
.B merge
tries to do it anyway.
.br