xref: /netbsd-src/usr.bin/comm/comm.c (revision 2a399c6883d870daece976daec6ffa7bb7f934ce)
1 /*	$NetBSD: comm.c,v 1.11 1997/10/18 13:04:27 lukem 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
47 static char sccsid[] = "@(#)comm.c	8.4 (Berkeley) 5/4/95";
48 #endif
49 __RCSID("$NetBSD: comm.c,v 1.11 1997/10/18 13:04:27 lukem 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 
62 char *tabs[] = { "", "\t", "\t\t" };
63 
64 FILE   *file __P((const char *));
65 int	main __P((int, char **));
66 void	show __P((FILE *, char *, char *));
67 void	usage __P((void));
68 
69 int
70 main(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 	file1done = file2done = 0;
83 	flag1 = flag2 = flag3 = 1;
84 	while ((ch = getopt(argc, argv, "123")) != -1)
85 		switch(ch) {
86 		case '1':
87 			flag1 = 0;
88 			break;
89 		case '2':
90 			flag2 = 0;
91 			break;
92 		case '3':
93 			flag3 = 0;
94 			break;
95 		case '?':
96 		default:
97 			usage();
98 		}
99 	argc -= optind;
100 	argv += optind;
101 
102 	if (argc != 2)
103 		usage();
104 
105 	fp1 = file(argv[0]);
106 	fp2 = file(argv[1]);
107 
108 	/* for each column printed, add another tab offset */
109 	p = tabs;
110 	col1 = col2 = col3 = NULL;
111 	if (flag1)
112 		col1 = *p++;
113 	if (flag2)
114 		col2 = *p++;
115 	if (flag3)
116 		col3 = *p;
117 
118 	for (read1 = read2 = 1;;) {
119 		/* read next line, check for EOF */
120 		if (read1)
121 			file1done = !fgets(line1, MAXLINELEN, fp1);
122 		if (read2)
123 			file2done = !fgets(line2, MAXLINELEN, fp2);
124 
125 		/* if one file done, display the rest of the other file */
126 		if (file1done) {
127 			if (!file2done && col2)
128 				show(fp2, col2, line2);
129 			break;
130 		}
131 		if (file2done) {
132 			if (!file1done && col1)
133 				show(fp1, col1, line1);
134 			break;
135 		}
136 
137 		/* lines are the same */
138 		if (!(comp = strcoll(line1, line2))) {
139 			read1 = read2 = 1;
140 			if (col3)
141 				if (printf("%s%s", col3, line1) < 0)
142 					break;
143 			continue;
144 		}
145 
146 		/* lines are different */
147 		if (comp < 0) {
148 			read1 = 1;
149 			read2 = 0;
150 			if (col1)
151 				if (printf("%s%s", col1, line1) < 0)
152 					break;
153 		} else {
154 			read1 = 0;
155 			read2 = 1;
156 			if (col2)
157 				if (printf("%s%s", col2, line2) < 0)
158 					break;
159 		}
160 	}
161 
162 	if (ferror (stdout) || fclose (stdout) == EOF)
163 		err(1, "stdout");
164 
165 	exit(0);
166 }
167 
168 void
169 show(fp, offset, buf)
170 	FILE *fp;
171 	char *offset, *buf;
172 {
173 	while (printf("%s%s", offset, buf) >= 0 && fgets(buf, MAXLINELEN, fp))
174 		;
175 }
176 
177 FILE *
178 file(name)
179 	const char *name;
180 {
181 	FILE *fp;
182 
183 	if (!strcmp(name, "-"))
184 		return (stdin);
185 	if ((fp = fopen(name, "r")) == NULL)
186 		err(1, "%s", name);
187 	return (fp);
188 }
189 
190 void
191 usage()
192 {
193 
194 	(void)fprintf(stderr, "usage: comm [-123] file1 file2\n");
195 	exit(1);
196 }
197