comm.c revision 1.12 
1/*	$NetBSD: comm.c,v 1.12 1999/02/11 00:53:24 hubertf 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 1.12 1999/02/11 00:53:24 hubertf 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	int (*compare)(const char*,const char*);
80
81	(void)setlocale(LC_ALL, "");
82
83	file1done = file2done = 0;
84	flag1 = flag2 = flag3 = 1;
85	compare = strcoll;
86	while ((ch = getopt(argc, argv, "123f")) != -1)
87		switch(ch) {
88		case '1':
89			flag1 = 0;
90			break;
91		case '2':
92			flag2 = 0;
93			break;
94		case '3':
95			flag3 = 0;
96			break;
97		case 'f':
98			compare = strcasecmp;
99			break;
100		case '?':
101		default:
102			usage();
103		}
104	argc -= optind;
105	argv += optind;
106
107	if (argc != 2)
108		usage();
109
110	fp1 = file(argv[0]);
111	fp2 = file(argv[1]);
112
113	/* for each column printed, add another tab offset */
114	p = tabs;
115	col1 = col2 = col3 = NULL;
116	if (flag1)
117		col1 = *p++;
118	if (flag2)
119		col2 = *p++;
120	if (flag3)
121		col3 = *p;
122
123	for (read1 = read2 = 1;;) {
124		/* read next line, check for EOF */
125		if (read1)
126			file1done = !fgets(line1, MAXLINELEN, fp1);
127		if (read2)
128			file2done = !fgets(line2, MAXLINELEN, fp2);
129
130		/* if one file done, display the rest of the other file */
131		if (file1done) {
132			if (!file2done && col2)
133				show(fp2, col2, line2);
134			break;
135		}
136		if (file2done) {
137			if (!file1done && col1)
138				show(fp1, col1, line1);
139			break;
140		}
141
142		/* lines are the same */
143		if (!(comp = compare(line1, line2))) {
144			read1 = read2 = 1;
145			if (col3)
146				if (printf("%s%s", col3, line1) < 0)
147					break;
148			continue;
149		}
150
151		/* lines are different */
152		if (comp < 0) {
153			read1 = 1;
154			read2 = 0;
155			if (col1)
156				if (printf("%s%s", col1, line1) < 0)
157					break;
158		} else {
159			read1 = 0;
160			read2 = 1;
161			if (col2)
162				if (printf("%s%s", col2, line2) < 0)
163					break;
164		}
165	}
166
167	if (ferror (stdout) || fclose (stdout) == EOF)
168		err(1, "stdout");
169
170	exit(0);
171}
172
173void
174show(fp, offset, buf)
175	FILE *fp;
176	char *offset, *buf;
177{
178	while (printf("%s%s", offset, buf) >= 0 && fgets(buf, MAXLINELEN, fp))
179		;
180}
181
182FILE *
183file(name)
184	const char *name;
185{
186	FILE *fp;
187
188	if (!strcmp(name, "-"))
189		return (stdin);
190	if ((fp = fopen(name, "r")) == NULL)
191		err(1, "%s", name);
192	return (fp);
193}
194
195void
196usage()
197{
198
199	(void)fprintf(stderr, "usage: comm [-123] file1 file2\n");
200	exit(1);
201}
202