comm.c revision 1.13 
1/*	$NetBSD: comm.c,v 1.13 2003/08/07 11:13:27 agc 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. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#include <sys/cdefs.h>
36#ifndef lint
37__COPYRIGHT("@(#) Copyright (c) 1989, 1993, 1994\n\
38	The Regents of the University of California.  All rights reserved.\n");
39#endif /* not lint */
40
41#ifndef lint
42#if 0
43static char sccsid[] = "@(#)comm.c	8.4 (Berkeley) 5/4/95";
44#endif
45__RCSID("$NetBSD: comm.c,v 1.13 2003/08/07 11:13:27 agc Exp $");
46#endif /* not lint */
47
48#include <err.h>
49#include <limits.h>
50#include <locale.h>
51#include <stdio.h>
52#include <stdlib.h>
53#include <string.h>
54#include <unistd.h>
55
56#define	MAXLINELEN	(LINE_MAX + 1)
57
58char *tabs[] = { "", "\t", "\t\t" };
59
60FILE   *file __P((const char *));
61int	main __P((int, char **));
62void	show __P((FILE *, char *, char *));
63void	usage __P((void));
64
65int
66main(argc, argv)
67	int argc;
68	char **argv;
69{
70	int comp, file1done, file2done, read1, read2;
71	int ch, flag1, flag2, flag3;
72	FILE *fp1, *fp2;
73	char *col1, *col2, *col3;
74	char **p, line1[MAXLINELEN], line2[MAXLINELEN];
75	int (*compare)(const char*,const char*);
76
77	(void)setlocale(LC_ALL, "");
78
79	file1done = file2done = 0;
80	flag1 = flag2 = flag3 = 1;
81	compare = strcoll;
82	while ((ch = getopt(argc, argv, "123f")) != -1)
83		switch(ch) {
84		case '1':
85			flag1 = 0;
86			break;
87		case '2':
88			flag2 = 0;
89			break;
90		case '3':
91			flag3 = 0;
92			break;
93		case 'f':
94			compare = strcasecmp;
95			break;
96		case '?':
97		default:
98			usage();
99		}
100	argc -= optind;
101	argv += optind;
102
103	if (argc != 2)
104		usage();
105
106	fp1 = file(argv[0]);
107	fp2 = file(argv[1]);
108
109	/* for each column printed, add another tab offset */
110	p = tabs;
111	col1 = col2 = col3 = NULL;
112	if (flag1)
113		col1 = *p++;
114	if (flag2)
115		col2 = *p++;
116	if (flag3)
117		col3 = *p;
118
119	for (read1 = read2 = 1;;) {
120		/* read next line, check for EOF */
121		if (read1)
122			file1done = !fgets(line1, MAXLINELEN, fp1);
123		if (read2)
124			file2done = !fgets(line2, MAXLINELEN, fp2);
125
126		/* if one file done, display the rest of the other file */
127		if (file1done) {
128			if (!file2done && col2)
129				show(fp2, col2, line2);
130			break;
131		}
132		if (file2done) {
133			if (!file1done && col1)
134				show(fp1, col1, line1);
135			break;
136		}
137
138		/* lines are the same */
139		if (!(comp = compare(line1, line2))) {
140			read1 = read2 = 1;
141			if (col3)
142				if (printf("%s%s", col3, line1) < 0)
143					break;
144			continue;
145		}
146
147		/* lines are different */
148		if (comp < 0) {
149			read1 = 1;
150			read2 = 0;
151			if (col1)
152				if (printf("%s%s", col1, line1) < 0)
153					break;
154		} else {
155			read1 = 0;
156			read2 = 1;
157			if (col2)
158				if (printf("%s%s", col2, line2) < 0)
159					break;
160		}
161	}
162
163	if (ferror (stdout) || fclose (stdout) == EOF)
164		err(1, "stdout");
165
166	exit(0);
167}
168
169void
170show(fp, offset, buf)
171	FILE *fp;
172	char *offset, *buf;
173{
174	while (printf("%s%s", offset, buf) >= 0 && fgets(buf, MAXLINELEN, fp))
175		;
176}
177
178FILE *
179file(name)
180	const char *name;
181{
182	FILE *fp;
183
184	if (!strcmp(name, "-"))
185		return (stdin);
186	if ((fp = fopen(name, "r")) == NULL)
187		err(1, "%s", name);
188	return (fp);
189}
190
191void
192usage()
193{
194
195	(void)fprintf(stderr, "usage: comm [-123] file1 file2\n");
196	exit(1);
197}
198