xref: /netbsd-src/usr.bin/comm/comm.c (revision ce0bb6e8d2e560ecacbe865a848624f94498063b)
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
40 static 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
47 static char sccsid[] = "@(#)comm.c	8.3 (Berkeley) 4/2/94";
48 #else
49 static 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 
63 char *tabs[] = { "", "\t", "\t\t" };
64 
65 FILE   *file __P((const 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 	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 
167 void
168 show(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 
176 FILE *
177 file(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 
189 void
190 usage()
191 {
192 
193 	(void)fprintf(stderr, "usage: comm [-123] file1 file2\n");
194 	exit(1);
195 }
196