DragonFlyBSD

diff3prog \

.PATH: ${.CURDIR}/../../usr.bin/diff3

PROG= diff3prog

SRCS= diff3prog.c

MAN= diff3.1

.include <bsd.prog.mk>

/* $OpenBSD: diff3prog.c,v 1.21 2021/04/13 14:20:23 stsp Exp $ */

/*

* Copyright (C) Caldera International Inc. 2001-2002.

* All rights reserved.

*

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions

* are met:

* 1. Redistributions of source code and documentation must retain the above

* copyright notice, this list of conditions and the following disclaimer.

* 2. Redistributions in binary form must reproduce the above copyright

* notice, this list of conditions and the following disclaimer in the

* documentation and/or other materials provided with the distribution.

* 3. All advertising materials mentioning features or use of this software

* must display the following acknowledgement:

* This product includes software developed or owned by Caldera

* International, Inc.

* 4. Neither the name of Caldera International, Inc. nor the names of other

* contributors may be used to endorse or promote products derived from

* this software without specific prior written permission.

*

* USE OF THE SOFTWARE PROVIDED FOR UNDER THIS LICENSE BY CALDERA

* INTERNATIONAL, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR

* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

* IN NO EVENT SHALL CALDERA INTERNATIONAL, INC. BE LIABLE FOR ANY DIRECT,

* INDIRECT INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR

* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING

* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

* POSSIBILITY OF SUCH DAMAGE.

*/

/*-

* Copyright (c) 1991, 1993

* The Regents of the University of California. All rights reserved.

*

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions

* are met:

* 1. Redistributions of source code must retain the above copyright

* notice, this list of conditions and the following disclaimer.

* 2. Redistributions in binary form must reproduce the above copyright

* notice, this list of conditions and the following disclaimer in the

* documentation and/or other materials provided with the distribution.

* 3. Neither the name of the University nor the names of its contributors

* may be used to endorse or promote products derived from this software

* without specific prior written permission.

*

* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND

* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE

* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

* SUCH DAMAGE.

*

* @(#)diff3.c 8.1 (Berkeley) 6/6/93

*/

#include <ctype.h>

#include <err.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

/* diff3 - 3-way differential file comparison */

/* diff3 [-ex3EX] d13 d23 f1 f2 f3 [m1 m3]

*

* d13 = diff report on f1 vs f3

* d23 = diff report on f2 vs f3

* f1, f2, f3 the 3 files

* if changes in f1 overlap with changes in f3, m1 and m3 are used

* to mark the overlaps; otherwise, the file names f1 and f3 are used

* (only for options E and X).

*/

/*

* "from" is first in range of changed lines; "to" is last+1

* from=to=line after point of insertion for added lines.

*/

struct range {

int from;

int to;

};

struct diff {

struct range old;

struct range new;

};

size_t szchanges;

struct diff *d13;

struct diff *d23;

/*

* "de" is used to gather editing scripts. These are later spewed out in

* reverse order. Its first element must be all zero, the "new" component

* of "de" contains line positions or byte positions depending on when you

* look (!?). Array overlap indicates which sections in "de" correspond to

* lines that are different in all three files.

*/

struct diff *de;

char *overlap;

int overlapcnt;

FILE *fp[3];

int cline[3]; /* # of the last-read line in each file (0-2) */

/*

* the latest known correspondence between line numbers of the 3 files

* is stored in last[1-3];

*/

int last[4];

int eflag;

int oflag; /* indicates whether to mark overlaps (-E or -X)*/

int debug = 0;

char f1mark[40], f3mark[40]; /* markers for -E and -X */

int duplicate(struct range *, struct range *);

int edit(struct diff *, int, int);

char *getchange(FILE *);

char *get_line(FILE *, size_t *);

int number(char **);

int readin(char *, struct diff **);

int skip(int, int, const char *);

void change(int, struct range *, int);

void keep(int, struct range *);

void merge(int, int);

void prange(struct range *);

void repos(int);

void separate(const char *);

void edscript(int);

void trouble(void);

void increase(void);

void usage(void);

int

main(int argc, char **argv)

{

int ch, i, m, n;

eflag = 0;

oflag = 0;

while ((ch = getopt(argc, argv, "EeXx3")) != -1) {

switch (ch) {

case 'E':

eflag = 3;

oflag = 1;

break;

case 'e':

eflag = 3;

break;

case 'X':

oflag = eflag = 1;

break;

case 'x':

eflag = 1;

break;

case '3':

eflag = 2;

break;

}

}

argc -= optind;

argv += optind;

/* XXX - argc usage seems wrong here */

if (argc < 5)

usage();

if (oflag) {

(void)snprintf(f1mark, sizeof(f1mark), "<<<<<<< %s",

argc >= 6 ? argv[5] : argv[2]);

(void)snprintf(f3mark, sizeof(f3mark), ">>>>>>> %s",

argc >= 7 ? argv[6] : argv[4]);

}

increase();

m = readin(argv[0], &d13);

n = readin(argv[1], &d23);

for (i = 0; i <= 2; i++) {

if ((fp[i] = fopen(argv[i + 2], "r")) == NULL)

err(EXIT_FAILURE, "can't open %s", argv[i + 2]);

}

merge(m, n);

exit(EXIT_SUCCESS);

}

/*

* Pick up the line numbers of all changes from one change file.

* (This puts the numbers in a vector, which is not strictly necessary,

* since the vector is processed in one sequential pass.

* The vector could be optimized out of existence)

*/

int

readin(char *name, struct diff **dd)

{

int a, b, c, d;

size_t i;

char kind, *p;

fp[0] = fopen(name, "r");

if (fp[0] == NULL)

err(EXIT_FAILURE, "can't open %s", name);

for (i=0; (p = getchange(fp[0])); i++) {

if (i >= szchanges - 1)

increase();

a = b = number(&p);

if (*p == ',') {

p++;

b = number(&p);

}

kind = *p++;

c = d = number(&p);

if (*p==',') {

p++;

d = number(&p);

}

if (kind == 'a')

a++;

if (kind == 'd')

c++;

b++;

d++;

(*dd)[i].old.from = a;

(*dd)[i].old.to = b;

(*dd)[i].new.from = c;

(*dd)[i].new.to = d;

}

if (i) {

(*dd)[i].old.from = (*dd)[i-1].old.to;

(*dd)[i].new.from = (*dd)[i-1].new.to;

}

(void)fclose(fp[0]);

return (i);

}

int

number(char **lc)

{

int nn;

nn = 0;

while (isdigit((unsigned char)(**lc)))

nn = nn*10 + *(*lc)++ - '0';

return (nn);

}

char *

getchange(FILE *b)

{

char *line;

while ((line = get_line(b, NULL))) {

if (isdigit((unsigned char)line[0]))

return (line);

}

return (NULL);

}

char *

get_line(FILE *b, size_t *n)

{

char *cp;

size_t len;

static char *buf;

static size_t bufsize;

if ((cp = fgetln(b, &len)) == NULL)

return (NULL);

if (cp[len - 1] != '\n')

len++;

if (len + 1 > bufsize) {

do {

bufsize += 1024;

} while (len + 1 > bufsize);

if ((buf = realloc(buf, bufsize)) == NULL)

err(EXIT_FAILURE, NULL);

}

memcpy(buf, cp, len - 1);

buf[len - 1] = '\n';

buf[len] = '\0';

if (n != NULL)

*n = len;

return (buf);

}

void

merge(int m1, int m2)

{

struct diff *d1, *d2, *d3;

int dup, j, t1, t2;

d1 = d13;

d2 = d23;

j = 0;

for (;;) {

t1 = (d1 < d13 + m1);

t2 = (d2 < d23 + m2);

if (!t1 && !t2)

break;

if (debug) {

printf("%d,%d=%d,%d %d,%d=%d,%d\n",

d1->old.from,d1->old.to,

d1->new.from,d1->new.to,

d2->old.from,d2->old.to,

d2->new.from,d2->new.to);

}

/* first file is different from others */

if (!t2 || (t1 && d1->new.to < d2->new.from)) {

/* stuff peculiar to 1st file */

if (eflag==0) {

separate("1");

change(1, &d1->old, 0);

keep(2, &d1->new);

change(3, &d1->new, 0);

}

d1++;

continue;

}

/* second file is different from others */

if (!t1 || (t2 && d2->new.to < d1->new.from)) {

if (eflag==0) {

separate("2");

keep(1, &d2->new);

change(2, &d2->old, 0);

change(3, &d2->new, 0);

}

d2++;

continue;

}

/*

* Merge overlapping changes in first file

* this happens after extension (see below).

*/

if (d1 + 1 < d13 + m1 && d1->new.to >= d1[1].new.from) {

d1[1].old.from = d1->old.from;

d1[1].new.from = d1->new.from;

d1++;

continue;

}

/* merge overlapping changes in second */

if (d2 + 1 < d23 + m2 && d2->new.to >= d2[1].new.from) {

d2[1].old.from = d2->old.from;

d2[1].new.from = d2->new.from;

d2++;

continue;

}

/* stuff peculiar to third file or different in all */

if (d1->new.from == d2->new.from && d1->new.to == d2->new.to) {

dup = duplicate(&d1->old,&d2->old);

/*

* dup = 0 means all files differ

* dup = 1 means files 1 and 2 identical

*/

if (eflag==0) {

separate(dup ? "3" : "");

change(1, &d1->old, dup);

change(2, &d2->old, 0);

d3 = d1->old.to > d1->old.from ? d1 : d2;

change(3, &d3->new, 0);

} else

j = edit(d1, dup, j);

d1++;

d2++;

continue;

}

/*

* Overlapping changes from file 1 and 2; extend changes

* appropriately to make them coincide.

*/

if (d1->new.from < d2->new.from) {

d2->old.from -= d2->new.from-d1->new.from;

d2->new.from = d1->new.from;

} else if (d2->new.from < d1->new.from) {

d1->old.from -= d1->new.from-d2->new.from;

d1->new.from = d2->new.from;

}

if (d1->new.to > d2->new.to) {

d2->old.to += d1->new.to - d2->new.to;

d2->new.to = d1->new.to;

} else if (d2->new.to > d1->new.to) {

d1->old.to += d2->new.to - d1->new.to;

d1->new.to = d2->new.to;

}

}

if (eflag)

edscript(j);

}

void

separate(const char *s)

{

printf("====%s\n", s);

}

/*

* The range of lines rold.from thru rold.to in file i is to be changed.

* It is to be printed only if it does not duplicate something to be

* printed later.

*/

void

change(int i, struct range *rold, int dup)

{

printf("%d:", i);

last[i] = rold->to;

prange(rold);

if (dup || debug)

return;

i--;

(void)skip(i, rold->from, NULL);

(void)skip(i, rold->to, " ");

}

/*

* print the range of line numbers, rold.from thru rold.to, as n1,n2 or n1

*/

void

prange(struct range *rold)

{

if (rold->to <= rold->from)

printf("%da\n", rold->from - 1);

else {

printf("%d", rold->from);

if (rold->to > rold->from+1)

printf(",%d", rold->to - 1);

printf("c\n");

}

}

/*

* No difference was reported by diff between file 1 (or 2) and file 3,

* and an artificial dummy difference (trange) must be ginned up to

* correspond to the change reported in the other file.

*/

void

keep(int i, struct range *rnew)

{

int delta;

struct range trange;

delta = last[3] - last[i];

trange.from = rnew->from - delta;

trange.to = rnew->to - delta;

change(i, &trange, 1);

}

/*

* skip to just before line number from in file "i". If "pr" is non-NULL,

* print all skipped stuff with string pr as a prefix.

*/

int

skip(int i, int from, const char *pr)

{

size_t j, n;

char *line;

for (n = 0; cline[i] < from - 1; n += j) {

if ((line = get_line(fp[i], &j)) == NULL)

trouble();

if (pr != NULL)

printf("%s%s", pr, line);

cline[i]++;

}

return ((int) n);

}

/*

* Return 1 or 0 according as the old range (in file 1) contains exactly

* the same data as the new range (in file 2).

*/

int

duplicate(struct range *r1, struct range *r2)

{

int c,d;

int nchar;

int nline;

if (r1->to-r1->from != r2->to-r2->from)

return (0);

(void)skip(0, r1->from, NULL);

(void)skip(1, r2->from, NULL);

nchar = 0;

for (nline=0; nline < r1->to - r1->from; nline++) {

do {

c = getc(fp[0]);

d = getc(fp[1]);

if (c == -1 && d == -1)

break;

if (c == -1 || d== -1)

trouble();

nchar++;

if (c != d) {

repos(nchar);

return (0);

}

} while (c != '\n');

}

repos(nchar);

return (1);

}

void

repos(int nchar)

{

int i;

for (i = 0; i < 2; i++)

(void)fseek(fp[i], (long)-nchar, SEEK_CUR);

}

void

trouble(void)

{

errx(EXIT_FAILURE, "logic error");

}

/*

* collect an editing script for later regurgitation

*/

int

edit(struct diff *diff, int dup, int j)

{

if (((dup + 1) & eflag) == 0)

return (j);

j++;

overlap[j] = !dup;

if (!dup)

overlapcnt++;

de[j].old.from = diff->old.from;

de[j].old.to = diff->old.to;

de[j].new.from = de[j-1].new.to + skip(2, diff->new.from, NULL);

de[j].new.to = de[j].new.from + skip(2, diff->new.to, NULL);

return (j);

}

/* regurgitate */

void

edscript(int n)

{

int k;

size_t j;

char block[BUFSIZ];

for (; n > 0; n--) {

if (!oflag || !overlap[n])

prange(&de[n].old);

else

printf("%da\n=======\n", de[n].old.to -1);

(void)fseek(fp[2], (long)de[n].new.from, SEEK_SET);

for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {

size_t r;

j = k > BUFSIZ ? BUFSIZ : k;

r = fread(block, 1, j, fp[2]);

if (r == 0) {

if (feof(fp[2]))

break;

trouble();

}

if (r != j)

j = r;

(void)fwrite(block, 1, j, stdout);

}

if (!oflag || !overlap[n])

printf(".\n");

else {

printf("%s\n.\n", f3mark);

printf("%da\n%s\n.\n", de[n].old.from - 1, f1mark);

}

}

exit(overlapcnt);

}

void

increase(void)

{

struct diff *p;

char *q;

size_t newsz, incr;

/* are the memset(3) calls needed? */

newsz = szchanges == 0 ? 64 : 2 * szchanges;

incr = newsz - szchanges;

p = reallocarray(d13, newsz, sizeof(struct diff));

if (p == NULL)

err(1, NULL);

memset(p + szchanges, 0, incr * sizeof(struct diff));

d13 = p;

p = reallocarray(d23, newsz, sizeof(struct diff));

if (p == NULL)

err(1, NULL);

memset(p + szchanges, 0, incr * sizeof(struct diff));

d23 = p;

p = reallocarray(de, newsz, sizeof(struct diff));

if (p == NULL)

err(1, NULL);

memset(p + szchanges, 0, incr * sizeof(struct diff));

de = p;

q = reallocarray(overlap, newsz, sizeof(char));

if (q == NULL)

err(1, NULL);

memset(q + szchanges, 0, incr * sizeof(char));

overlap = q;

szchanges = newsz;

}

void

usage(void)

{

//extern char *__progname;

fprintf(stderr, "usage: %s [-exEX3] /tmp/d3a.?????????? "

"/tmp/d3b.?????????? file1 file2 file3\n", "diff3");

exit(EXIT_FAILURE);

}

diff3 \

# $OpenBSD: Makefile,v 1.2 2003/07/22 00:11:30 millert Exp $

MAN= diff3.1

beforeinstall:

install ${INSTALL_COPY} -o ${BINOWN} -g ${BINGRP} -m ${BINMODE} \

${.CURDIR}/diff3 ${DESTDIR}/usr/bin/

.include <bsd.prog.mk>

#!/bin/sh

#

# $OpenBSD: diff3.ksh,v 1.6 2019/09/28 17:30:07 ajacoutot Exp $

#

# Copyright (c) 2003 Todd C. Miller <millert@openbsd.org>

#

# Permission to use, copy, modify, and distribute this software for any

# purpose with or without fee is hereby granted, provided that the above

# copyright notice and this permission notice appear in all copies.

#

# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

#

# Sponsored in part by the Defense Advanced Research Projects

# Agency (DARPA) and Air Force Research Laboratory, Air Force

# Materiel Command, USAF, under agreement number F39502-99-1-0512.

#

OPTIND=1 # force getopts to reset itself

export PATH=/usr/bin:/bin:/usr/sbin:/sbin

diff3prog=/usr/libexec/diff3prog

USAGE="usage: diff3 [-3aEeXx] file1 file2 file3"

# Pull out any command line flags (some for diff, some for diff3)

dflags=

d3flags=

while getopts "aeExX3" c; do

case "$c" in

a)

dflags="$dflags -$c"

;;

e|E|x|X|3)

d3flags="-$c"

;;

*)

echo "$USAGE" 1>&2

exit 1

;;

esac

done

shift $(( $OPTIND - 1 ))

if [ $# -lt 3 ]; then

echo "$USAGE" 1>&2

exit 1

fi

TMP1=`mktemp -t d3a.XXXXXXXXXX` || exit 1

TMP2=`mktemp -t d3b.XXXXXXXXXX`

if [ $? -ne 0 ]; then

rm -f $TMP1

exit 1

fi

trap "/bin/rm -f $TMP1 $TMP2" 0 1 2 13 15

diff $dflags -- $1 $3 > $TMP1

diff $dflags -- $2 $3 > $TMP2

$diff3prog $d3flags -- $TMP1 $TMP2 $1 $2 $3

exit $?

.\" $OpenBSD: diff3.1,v 1.7 2007/05/31 19:20:09 jmc Exp $

.\"

.\" Copyright (c) 1990, 1993, 1994

.\" The Regents of the University of California. All rights reserved.

.\"

.\" Redistribution and use in source and binary forms, with or without

.\" modification, are permitted provided that the following conditions

.\" are met:

.\" 1. Redistributions of source code must retain the above copyright

.\" notice, this list of conditions and the following disclaimer.

.\" 2. Redistributions in binary form must reproduce the above copyright

.\" notice, this list of conditions and the following disclaimer in the

.\" documentation and/or other materials provided with the distribution.

.\" 3. Neither the name of the University nor the names of its contributors

.\" may be used to endorse or promote products derived from this software

.\" without specific prior written permission.

.\"

.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND

.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE

.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

.\" SUCH DAMAGE.

.\"

.\" @(#)diff3.1 8.2 (Berkeley) 4/18/94

.\"

.Dd $Mdocdate: May 31 2007 $

.Dt DIFF3 1

.Os

.Sh NAME

.Nm diff3

.Nd 3-way differential file comparison

.Sh SYNOPSIS

.Nm diff3

.Op Fl 3aEeXx

.Ar file1 file2 file3

.Sh DESCRIPTION

The

.Nm

utility compares the contents of three different versions of a file,

.Ar file1 ,

.Ar file2

and

.Ar file3 ,

writing the result to the standard output.

The options describe different methods of merging and

purging

the separate versions into a new file.

.Nm

is used by

.Xr rcs 1

to merge specific versions or create

new versions.

.Pp

The options are as follows:

.Bl -tag -width "-E, -X"

.It Fl 3

Produces an output script suitable for

.Xr ed 1

with changes

specific only to

.Ar file3 .

.It Fl a

Treat all files as ASCII.

.It Fl E , X

Similar to

.Fl e

and

.Fl x ,

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.

.It Fl e

Produces output in a form suitable as an input script for the

.Xr ed 1

utility.

The script may then be used to merge differences common between all

three files and differences specific to

.Ar file1

and

.Ar file3 .

In other words, the

.Fl e

option ignores differences specific to

.Ar file1

and

.Ar file2 ,

and those specific to

.Ar file2

and

.Ar file3 .

It is useful for backing out changes specific to

.Ar file2

only.

.It Fl x

Produces an output script suitable for

.Xr ed 1

with changes

specific only to all three versions.

.El

.Pp

The

.Fl E

option is used by

.Tn RCS

.Xr merge 1

to ensure that overlapping changes in the merged files are preserved

and brought to someone's attention.

.Pp

For example, suppose lines 7-8 are changed in both

.Ar file1

and

.Ar file2 .

Applying the edit script generated by the command

.Pp

.Dl $ diff3 -E file1 file2 file3

.Pp

to

.Ar file1

results in the file:

.Bd -literal -offset indent

lines 1-6

of file1

<<<<<<< file1

lines 7-8

of file1

=======

lines 7-8

of file3

>>>>>>> file3

rest of file1

.Ed

.Pp

The default output of

.Nm

makes notation of the differences between all files, and those

differences specific to each pair of files.

The changes are described by the commands necessary for

.Xr ed 1

to create the desired target from the different versions.

See

.Xr diff 1

for a description of the commands.

.Bl -tag -width "====="

.It Li \&====

The lines beneath this notation are ranges of lines which are different

between all files.

.It \&==== Ns Va n

The lines beneath this notation are ranges of lines which are exclusively

different in file

.Va n .

.El

.Sh ENVIRONMENT

.Bl -tag -width TMPDIR

.It Ev TMPDIR

If the environment variable

.Ev TMPDIR

exists,

.Nm

will use the directory specified by

.Ev TMPDIR

as the temporary directory.

.El

.Sh FILES

.Bl -tag -width /usr/libexec/diff3prog -compact

.It Pa /tmp/d3a.XXXXXXXXXX

temporary file

.It Pa /tmp/d3b.XXXXXXXXXX

temporary file

.It Pa /usr/libexec/diff3prog

the actual executable

.El

.Sh SEE ALSO

.Xr diff 1 ,

.Xr ed 1 ,

.Xr merge 1 ,

.Xr rcs 1 ,

.Xr sdiff 1

.Sh HISTORY

A

.Nm

command appeared in

.At v7 .

.Sh BUGS

The

.Fl e

option cannot catch and change lines which have

.Ql \&.

as the first and only character on the line.

The resulting script will fail on that line

as

.Ql \&.

is an

.Xr ed 1

editing command.