comm.c revision 1.11 
1/*	$NetBSD: comm.c,v 1.11 1997/10/18 13:04:27 lukem Exp $	*/
2
3/*
4 * Copyright (c) 1989, 1993, 1994
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Case Larsen.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 *    must display the following acknowledgement:
20 *	This product includes software developed by the University of
21 *	California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 *    may be used to endorse or promote products derived from this software
24 *    without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 */
38
39#include <sys/cdefs.h>
40#ifndef lint
41__COPYRIGHT("@(#) Copyright (c) 1989, 1993, 1994\n\
42	The Regents of the University of California.  All rights reserved.\n");
43#endif /* not lint */
44
45#ifndef lint
46#if 0
47static char sccsid[] = "@(#)comm.c	8.4 (Berkeley) 5/4/95";
48#endif
49__RCSID("$NetBSD: comm.c,v 1.11 1997/10/18 13:04:27 lukem Exp $");
50#endif /* not lint */
51
52#include <err.h>
53#include <limits.h>
54#include <locale.h>
55#include <stdio.h>
56#include <stdlib.h>
57#include <string.h>
58#include <unistd.h>
59
60#define	MAXLINELEN	(LINE_MAX + 1)
61
62char *tabs[] = { "", "\t", "\t\t" };
63
64FILE   *file __P((const char *));
65int	main __P((int, char **));
66void	show __P((FILE *, char *, char *));
67void	usage __P((void));
68
69int
70main(argc, argv)
71	int argc;
72	char **argv;
73{
74	int comp, file1done, file2done, read1, read2;
75	int ch, flag1, flag2, flag3;
76	FILE *fp1, *fp2;
77	char *col1, *col2, *col3;
78	char **p, line1[MAXLINELEN], line2[MAXLINELEN];
79
80	setlocale(LC_ALL, "");
81
82	file1done = file2done = 0;
83	flag1 = flag2 = flag3 = 1;
84	while ((ch = getopt(argc, argv, "123")) != -1)
85		switch(ch) {
86		case '1':
87			flag1 = 0;
88			break;
89		case '2':
90			flag2 = 0;
91			break;
92		case '3':
93			flag3 = 0;
94			break;
95		case '?':
96		default:
97			usage();
98		}
99	argc -= optind;
100	argv += optind;
101
102	if (argc != 2)
103		usage();
104
105	fp1 = file(argv[0]);
106	fp2 = file(argv[1]);
107
108	/* for each column printed, add another tab offset */
109	p = tabs;
110	col1 = col2 = col3 = NULL;
111	if (flag1)
112		col1 = *p++;
113	if (flag2)
114		col2 = *p++;
115	if (flag3)
116		col3 = *p;
117
118	for (read1 = read2 = 1;;) {
119		/* read next line, check for EOF */
120		if (read1)
121			file1done = !fgets(line1, MAXLINELEN, fp1);
122		if (read2)
123			file2done = !fgets(line2, MAXLINELEN, fp2);
124
125		/* if one file done, display the rest of the other file */
126		if (file1done) {
127			if (!file2done && col2)
128				show(fp2, col2, line2);
129			break;
130		}
131		if (file2done) {
132			if (!file1done && col1)
133				show(fp1, col1, line1);
134			break;
135		}
136
137		/* lines are the same */
138		if (!(comp = strcoll(line1, line2))) {
139			read1 = read2 = 1;
140			if (col3)
141				if (printf("%s%s", col3, line1) < 0)
142					break;
143			continue;
144		}
145
146		/* lines are different */
147		if (comp < 0) {
148			read1 = 1;
149			read2 = 0;
150			if (col1)
151				if (printf("%s%s", col1, line1) < 0)
152					break;
153		} else {
154			read1 = 0;
155			read2 = 1;
156			if (col2)
157				if (printf("%s%s", col2, line2) < 0)
158					break;
159		}
160	}
161
162	if (ferror (stdout) || fclose (stdout) == EOF)
163		err(1, "stdout");
164
165	exit(0);
166}
167
168void
169show(fp, offset, buf)
170	FILE *fp;
171	char *offset, *buf;
172{
173	while (printf("%s%s", offset, buf) >= 0 && fgets(buf, MAXLINELEN, fp))
174		;
175}
176
177FILE *
178file(name)
179	const char *name;
180{
181	FILE *fp;
182
183	if (!strcmp(name, "-"))
184		return (stdin);
185	if ((fp = fopen(name, "r")) == NULL)
186		err(1, "%s", name);
187	return (fp);
188}
189
190void
191usage()
192{
193
194	(void)fprintf(stderr, "usage: comm [-123] file1 file2\n");
195	exit(1);
196}
197