comm.c revision 1.3 
1/*
2 * Copyright (c) 1989 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Case Larsen.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#ifndef lint
38char copyright[] =
39"@(#) Copyright (c) 1989 The Regents of the University of California.\n\
40 All rights reserved.\n";
41#endif /* not lint */
42
43#ifndef lint
44/*static char sccsid[] = "from: @(#)comm.c	5.7 (Berkeley) 11/1/90";*/
45static char rcsid[] = "$Id: comm.c,v 1.3 1993/09/21 23:20:36 jtc Exp $";
46#endif /* not lint */
47
48#include <stdio.h>
49#include <stdlib.h>
50#include <string.h>
51#include <limits.h>
52#include <locale.h>
53
54#define	MAXLINELEN	(_POSIX2_LINE_MAX + 1)
55
56char *tabs[] = { "", "\t", "\t\t" };
57
58FILE *file __P((const char *));
59void  show __P((FILE *, char *, char *));
60void  usage __P((void));
61
62int
63main(argc,argv)
64	int argc;
65	char **argv;
66{
67	register int comp, file1done, file2done, read1, read2;
68	register char *col1, *col2, *col3;
69	int ch, flag1, flag2, flag3;
70	FILE *fp1, *fp2;
71	char **p, line1[MAXLINELEN], line2[MAXLINELEN];
72
73	setlocale(LC_ALL, "");
74
75	flag1 = flag2 = flag3 = 1;
76	while ((ch = getopt(argc, argv, "123")) != -1)
77		switch(ch) {
78		case '1':
79			flag1 = 0;
80			break;
81		case '2':
82			flag2 = 0;
83			break;
84		case '3':
85			flag3 = 0;
86			break;
87		case '?':
88		default:
89			usage();
90		}
91	argc -= optind;
92	argv += optind;
93
94	if (argc != 2)
95		usage();
96
97	fp1 = file(argv[0]);
98	fp2 = file(argv[1]);
99
100	/* for each column printed, add another tab offset */
101	p = tabs;
102	col1 = col2 = col3 = NULL;
103	if (flag1)
104		col1 = *p++;
105	if (flag2)
106		col2 = *p++;
107	if (flag3)
108		col3 = *p;
109
110	for (read1 = read2 = 1;;) {
111		/* read next line, check for EOF */
112		if (read1)
113			file1done = !fgets(line1, MAXLINELEN, fp1);
114		if (read2)
115			file2done = !fgets(line2, MAXLINELEN, fp2);
116
117		/* if one file done, display the rest of the other file */
118		if (file1done) {
119			if (!file2done && col2)
120				show(fp2, col2, line2);
121			break;
122		}
123		if (file2done) {
124			if (!file1done && col1)
125				show(fp1, col1, line1);
126			break;
127		}
128
129		/* lines are the same */
130		if (!(comp = strcoll(line1, line2))) {
131			read1 = read2 = 1;
132			if (col3)
133				(void)printf("%s%s", col3, line1);
134			continue;
135		}
136
137		/* lines are different */
138		if (comp < 0) {
139			read1 = 1;
140			read2 = 0;
141			if (col1)
142				(void)printf("%s%s", col1, line1);
143		} else {
144			read1 = 0;
145			read2 = 1;
146			if (col2)
147				(void)printf("%s%s", col2, line2);
148		}
149	}
150	exit(0);
151}
152
153void
154show(fp, offset, buf)
155	FILE *fp;
156	char *offset, *buf;
157{
158	do {
159		(void)printf("%s%s", offset, buf);
160	} while (fgets(buf, MAXLINELEN, fp));
161}
162
163FILE *
164file(name)
165	const char *name;
166{
167	FILE *fp;
168
169	if (!strcmp(name, "-"))
170		return(stdin);
171	if (!(fp = fopen(name, "r"))) {
172		(void)fprintf(stderr, "comm: can't read %s.\n", name);
173		exit(1);
174	}
175	return(fp);
176}
177
178void
179usage()
180{
181	(void)fprintf(stderr, "usage: comm [-123] file1 file2\n");
182	exit(1);
183}
184