xref: /netbsd-src/usr.bin/comm/comm.c (revision 4b30c543a0b21e3ba94f2c569e9a82b4fdb2075f)
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
38 char 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";*/
45 static 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 
56 char *tabs[] = { "", "\t", "\t\t" };
57 
58 FILE *file __P((const char *));
59 void  show __P((FILE *, char *, char *));
60 void  usage __P((void));
61 
62 int
63 main(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 
153 void
154 show(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 
163 FILE *
164 file(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 
178 void
179 usage()
180 {
181 	(void)fprintf(stderr, "usage: comm [-123] file1 file2\n");
182 	exit(1);
183 }
184