A matching diff3 from 32V w/ some UCB changes. I cleaned this up a bit

(KNF and -Wall) and rewrote the shell front-end.

4 files changed, 840 insertions, 0 deletions

diff --git a/usr.bin/diff3/Makefile b/usr.bin/diff3/Makefile
new file mode 100644
index 00000000000..b6a2223fed9
--- /dev/null
+++ b/usr.bin/diff3/Makefile
@@ -0,0 +1,11 @@
+#	$OpenBSD: Makefile,v 1.1 2003/07/10 16:06:07 millert Exp $
+
+PROG=	diff3prog
+MAN=	diff3.1
+BINDIR=	/usr/libexec
+
+beforeinstall:
+	install ${INSTALL_COPY}c -o ${BINOWN} -g ${BINGRP} -m ${BINMODE} \
+	    ${.CURDIR}/diff3.ksh ${DESTDIR}/usr/bin/${PROG}
+
+.include <bsd.prog.mk>
diff --git a/usr.bin/diff3/diff3.1 b/usr.bin/diff3/diff3.1
new file mode 100644
index 00000000000..816e983262a
--- /dev/null
+++ b/usr.bin/diff3/diff3.1
@@ -0,0 +1,201 @@
+.\" $OpenBSD: diff3.1,v 1.1 2003/07/10 16:06:07 millert 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 April 18, 1994
+.Dt DIFF3 1
+.Os
+.Sh NAME
+.Nm diff3
+.Nd 3-way differential file comparison
+.Sh SYNOPSIS
+.Nm diff3
+.Op Fl aexEX3
+.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 a
+Treat all files as ASCII.
+.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.
+.It Fl 3
+Produces an output script suitable for
+.Xr ed 1
+with changes
+specific only to
+.Ar file3 .
+.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.
+.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:
+.Pp
+.Bd -literal -offset indent -compact
+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/diff3
+the actual executable
+.El
+.Sh SEE ALSO
+.Xr diff 1 ,
+.Xr ed 1 ,
+.Xr merge 1
+.Xr rcs 1
+.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.
+.Sh HISTORY
+A
+.Nm
+command appeared in
+.At v7 .
diff --git a/usr.bin/diff3/diff3.ksh b/usr.bin/diff3/diff3.ksh
new file mode 100644
index 00000000000..dd4991c6583
--- /dev/null
+++ b/usr.bin/diff3/diff3.ksh
@@ -0,0 +1,62 @@
+#!/bin/ksh -
+#
+# $OpenBSD: diff3.ksh,v 1.1 2003/07/10 16:06:07 millert Exp $
+#
+# Copyright (c) 2003 Todd C. Miller <Todd.Miller@courtesan.com>
+#
+# 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.
+#
+
+set -o posix		# set POSIX mode to prevent +foo in getopts
+OPTIND=1		# force getopts to reset itself
+
+export PATH=/bin:/usr/bin
+diff3prog=/usr/libexec/diff3prog
+USAGE="usage: diff3 [-aexEX3] 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 $1"
+			shift
+			;;
+		e|E|x|X|3)
+			d3flags="-$c"
+			shift
+			;;
+		*)
+			echo "$USAGE" 1>&2
+			exit 1
+			;;
+	esac
+done
+shift $(( $OPTIND - 1 ))
+
+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 $?
diff --git a/usr.bin/diff3/diff3prog.c b/usr.bin/diff3/diff3prog.c
new file mode 100644
index 00000000000..0f15350349e
--- /dev/null
+++ b/usr.bin/diff3/diff3prog.c
@@ -0,0 +1,566 @@
+/*	$OpenBSD: diff3prog.c,v 1.1 2003/07/10 16:06:07 millert 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
+ */
+
+#ifndef lint
+static const char copyright[] =
+"@(#) Copyright (c) 1991, 1993\n\
+	The Regents of the University of California.  All rights reserved.\n";
+#endif /* not lint */
+
+#ifndef lint
+static const char rcsid[] = "$OpenBSD: diff3prog.c,v 1.1 2003/07/10 16:06:07 millert Exp $";
+#endif /* not lint */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <err.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;
+};
+
+#define NC 200
+struct diff d13[NC];
+struct diff d23[NC];
+/*
+ * "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[NC];
+char overlap[NC];
+int  overlapcnt;
+char line[256];
+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);
+int getchange(FILE *);
+int getline(FILE *);
+int number(char **);
+int readin(char *, struct diff *);
+int skip(int, int, 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 *);
+__dead void edscript(int);
+__dead void trouble(void);
+__dead 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]);
+        }
+
+	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) {
+			printf("diff3: can't open %s\n", argv[i + 2]);
+			exit(EXIT_FAILURE);
+		}
+	}
+	merge(m, n);
+	exit(EXIT_SUCCESS);
+}
+
+/*
+ * Pick up the line numbers of allcahnges 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 i;
+	int a,b,c,d;
+	char kind;
+	char *p;
+	fp[0] = fopen(name, "r");
+	for (i=0; getchange(fp[0]); i++) {
+		if (i >= NC)
+			err(EXIT_FAILURE, "too many changes");
+		p = line;
+		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;
+	}
+	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);
+}
+
+int
+getchange(FILE *b)
+{
+	while (getline(b)) {
+		if (isdigit((unsigned char)line[0]))
+			return (1);
+	}
+	return (0);
+}
+
+int
+getline(FILE *b)
+{
+	int i, c;
+
+	for (i = 0; i < sizeof(line) - 1; i++) {
+		c = getc(b);
+		if (c == EOF)
+			break;
+		line[i] = c;
+		if (c == '\n') {
+			line[++i] = 0;
+			return (i);
+		}
+	}
+	return (0);
+}
+
+void
+merge(int m1, int m2)
+{
+	struct diff *d1, *d2, *d3;
+	int dup, j, t1, t2;
+
+	d1 = d13;
+	d2 = d23;
+	j = 0;
+	while ((t1 = d1 < d13 + m1) | (t2 = d2 < d23 + m2)) {
+		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 meands 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 befor 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, char *pr)
+{
+	int j, n;
+
+	for (n = 0; cline[i] < from - 1; n += j) {
+		if ((j = getline(fp[i])) == NULL)
+			trouble();
+		if (pr != NULL)
+			printf("%s%s", pr, line);
+		cline[i]++;
+	}
+	return (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)
+				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, 1);
+}
+
+__dead 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 */
+__dead void
+edscript(int n)
+{
+	int j,k;
+	char block[BUFSIZ];
+
+	for (n = n; 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, 0);
+		for (k = de[n].new.to-de[n].new.from; k > 0; k-= j) {
+			j = k > BUFSIZ ? BUFSIZ : k;
+			if (fread(block, 1, j, fp[2]) != j)
+				trouble();
+			(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);
+}
+
+__dead void
+usage(void)
+{
+	extern char *__progname;
+
+	fprintf(stderr, "usage: %s [-exEX3] /tmp/d3a.?????????? "
+	    "/tmp/d3b.?????????? file1 file2 file3\n", __progname);
+	exit(EXIT_FAILURE);
+}