comm.c revision 1.9 
1/*	$NetBSD: comm.c,v 1.9 1995/09/02 05:54:48 jtc 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	8.4 (Berkeley) 5/4/95";
48#endif
49static char rcsid[] = "$NetBSD: comm.c,v 1.9 1995/09/02 05:54:48 jtc 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 *));
65void	show __P((FILE *, char *, char *));
66void	usage __P((void));
67
68int
69main(argc, argv)
70	int argc;
71	char **argv;
72{
73	int comp, file1done, file2done, read1, read2;
74	int ch, flag1, flag2, flag3;
75	FILE *fp1, *fp2;
76	char *col1, *col2, *col3;
77	char **p, line1[MAXLINELEN], line2[MAXLINELEN];
78
79	setlocale(LC_ALL, "");
80
81	flag1 = flag2 = flag3 = 1;
82	while ((ch = getopt(argc, argv, "123")) != -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 '?':
94		default:
95			usage();
96		}
97	argc -= optind;
98	argv += optind;
99
100	if (argc != 2)
101		usage();
102
103	fp1 = file(argv[0]);
104	fp2 = file(argv[1]);
105
106	/* for each column printed, add another tab offset */
107	p = tabs;
108	col1 = col2 = col3 = NULL;
109	if (flag1)
110		col1 = *p++;
111	if (flag2)
112		col2 = *p++;
113	if (flag3)
114		col3 = *p;
115
116	for (read1 = read2 = 1;;) {
117		/* read next line, check for EOF */
118		if (read1)
119			file1done = !fgets(line1, MAXLINELEN, fp1);
120		if (read2)
121			file2done = !fgets(line2, MAXLINELEN, fp2);
122
123		/* if one file done, display the rest of the other file */
124		if (file1done) {
125			if (!file2done && col2)
126				show(fp2, col2, line2);
127			break;
128		}
129		if (file2done) {
130			if (!file1done && col1)
131				show(fp1, col1, line1);
132			break;
133		}
134
135		/* lines are the same */
136		if (!(comp = strcoll(line1, line2))) {
137			read1 = read2 = 1;
138			if (col3)
139				if (printf("%s%s", col3, line1) < 0)
140					break;
141			continue;
142		}
143
144		/* lines are different */
145		if (comp < 0) {
146			read1 = 1;
147			read2 = 0;
148			if (col1)
149				if (printf("%s%s", col1, line1) < 0)
150					break;
151		} else {
152			read1 = 0;
153			read2 = 1;
154			if (col2)
155				if (printf("%s%s", col2, line2) < 0)
156					break;
157		}
158	}
159
160	if (ferror (stdout) || fclose (stdout) == EOF)
161		err(1, "stdout");
162
163	exit(0);
164}
165
166void
167show(fp, offset, buf)
168	FILE *fp;
169	char *offset, *buf;
170{
171	while (printf("%s%s", offset, buf) < 0 && fgets(buf, MAXLINELEN, fp))
172		;
173}
174
175FILE *
176file(name)
177	const char *name;
178{
179	FILE *fp;
180
181	if (!strcmp(name, "-"))
182		return (stdin);
183	if ((fp = fopen(name, "r")) == NULL)
184		err(1, "%s", name);
185	return (fp);
186}
187
188void
189usage()
190{
191
192	(void)fprintf(stderr, "usage: comm [-123] file1 file2\n");
193	exit(1);
194}
195