comm.c revision 1.8 
1/*	$NetBSD: comm.c,v 1.8 1995/03/27 15:54:30 glass 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#ifndef lint
40static char copyright[] =
41"@(#) 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	8.3 (Berkeley) 4/2/94";
48#else
49static char rcsid[] = "$NetBSD: comm.c,v 1.8 1995/03/27 15:54:30 glass Exp $";
50#endif
51#endif /* not lint */
52
53#include <err.h>
54#include <limits.h>
55#include <locale.h>
56#include <stdio.h>
57#include <stdlib.h>
58#include <string.h>
59#include <unistd.h>
60
61#define	MAXLINELEN	(LINE_MAX + 1)
62
63char *tabs[] = { "", "\t", "\t\t" };
64
65FILE   *file __P((const 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	flag1 = flag2 = flag3 = 1;
83	while ((ch = getopt(argc, argv, "123")) != -1)
84		switch(ch) {
85		case '1':
86			flag1 = 0;
87			break;
88		case '2':
89			flag2 = 0;
90			break;
91		case '3':
92			flag3 = 0;
93			break;
94		case '?':
95		default:
96			usage();
97		}
98	argc -= optind;
99	argv += optind;
100
101	if (argc != 2)
102		usage();
103
104	fp1 = file(argv[0]);
105	fp2 = file(argv[1]);
106
107	/* for each column printed, add another tab offset */
108	p = tabs;
109	col1 = col2 = col3 = NULL;
110	if (flag1)
111		col1 = *p++;
112	if (flag2)
113		col2 = *p++;
114	if (flag3)
115		col3 = *p;
116
117	for (read1 = read2 = 1;;) {
118		/* read next line, check for EOF */
119		if (read1)
120			file1done = !fgets(line1, MAXLINELEN, fp1);
121		if (read2)
122			file2done = !fgets(line2, MAXLINELEN, fp2);
123
124		/* if one file done, display the rest of the other file */
125		if (file1done) {
126			if (!file2done && col2)
127				show(fp2, col2, line2);
128			break;
129		}
130		if (file2done) {
131			if (!file1done && col1)
132				show(fp1, col1, line1);
133			break;
134		}
135
136		/* lines are the same */
137		if (!(comp = strcoll(line1, line2))) {
138			read1 = read2 = 1;
139			if (col3)
140				if (printf("%s%s", col3, line1) < 0)
141					break;
142			continue;
143		}
144
145		/* lines are different */
146		if (comp < 0) {
147			read1 = 1;
148			read2 = 0;
149			if (col1)
150				if (printf("%s%s", col1, line1) < 0)
151					break;
152		} else {
153			read1 = 0;
154			read2 = 1;
155			if (col2)
156				if (printf("%s%s", col2, line2) < 0)
157					break;
158		}
159	}
160
161	if (ferror (stdout) || fclose (stdout) == EOF)
162		err(1, "stdout");
163
164	exit(0);
165}
166
167void
168show(fp, offset, buf)
169	FILE *fp;
170	char *offset, *buf;
171{
172	while (printf("%s%s", offset, buf) < 0 && fgets(buf, MAXLINELEN, fp))
173		;
174}
175
176FILE *
177file(name)
178	const char *name;
179{
180	FILE *fp;
181
182	if (!strcmp(name, "-"))
183		return (stdin);
184	if ((fp = fopen(name, "r")) == NULL)
185		err(1, "%s", name);
186	return (fp);
187}
188
189void
190usage()
191{
192
193	(void)fprintf(stderr, "usage: comm [-123] file1 file2\n");
194	exit(1);
195}
196