xref: /netbsd/usr.bin/cmp/cmp.c (revision bf9ec67e)
1 /*	$NetBSD: cmp.c,v 1.12 1998/01/12 08:11:19 mikel Exp $	*/
2 
3 /*
4  * Copyright (c) 1987, 1990, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT("@(#) Copyright (c) 1987, 1990, 1993, 1994\n\
39 	The Regents of the University of California.  All rights reserved.\n");
40 #endif /* not lint */
41 
42 #ifndef lint
43 #if 0
44 static char sccsid[] = "@(#)cmp.c	8.3 (Berkeley) 4/2/94";
45 #else
46 __RCSID("$NetBSD: cmp.c,v 1.12 1998/01/12 08:11:19 mikel Exp $");
47 #endif
48 #endif /* not lint */
49 
50 #include <sys/types.h>
51 #include <sys/stat.h>
52 
53 #include <err.h>
54 #include <fcntl.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <unistd.h>
59 #include <locale.h>
60 
61 #include "extern.h"
62 
63 int	lflag, sflag;
64 
65 int	main __P((int, char **));
66 static void usage __P((void));
67 
68 int
69 main(argc, argv)
70 	int argc;
71 	char *argv[];
72 {
73 	struct stat sb1, sb2;
74 	off_t skip1, skip2;
75 	int ch, fd1, fd2, special;
76 	char *file1, *file2;
77 
78 	setlocale(LC_ALL, "");
79 
80 	while ((ch = getopt(argc, argv, "ls")) != -1)
81 		switch (ch) {
82 		case 'l':		/* print all differences */
83 			lflag = 1;
84 			break;
85 		case 's':		/* silent run */
86 			sflag = 1;
87 			break;
88 		case '?':
89 		default:
90 			usage();
91 		}
92 	argv += optind;
93 	argc -= optind;
94 
95 	if (lflag && sflag)
96 		errx(ERR_EXIT, "only one of -l and -s may be specified");
97 
98 	if (argc < 2 || argc > 4)
99 		usage();
100 
101 	/* Backward compatibility -- handle "-" meaning stdin. */
102 	special = 0;
103 	if (strcmp(file1 = argv[0], "-") == 0) {
104 		special = 1;
105 		fd1 = 0;
106 		file1 = "stdin";
107 	}
108 	else if ((fd1 = open(file1, O_RDONLY, 0)) < 0) {
109 		if (!sflag)
110 			warn("%s", file1);
111 		exit(ERR_EXIT);
112 	}
113 	if (strcmp(file2 = argv[1], "-") == 0) {
114 		if (special)
115 			errx(ERR_EXIT,
116 				"standard input may only be specified once");
117 		special = 1;
118 		fd2 = 0;
119 		file2 = "stdin";
120 	}
121 	else if ((fd2 = open(file2, O_RDONLY, 0)) < 0) {
122 		if (!sflag)
123 			warn("%s", file2);
124 		exit(ERR_EXIT);
125 	}
126 
127 	skip1 = argc > 2 ? strtoq(argv[2], NULL, 10) : 0;
128 	skip2 = argc == 4 ? strtoq(argv[3], NULL, 10) : 0;
129 
130 	if (!special) {
131 		if (fstat(fd1, &sb1))
132 			err(ERR_EXIT, "%s", file1);
133 		if (!S_ISREG(sb1.st_mode))
134 			special = 1;
135 		else {
136 			if (fstat(fd2, &sb2))
137 				err(ERR_EXIT, "%s", file2);
138 			if (!S_ISREG(sb2.st_mode))
139 				special = 1;
140 		}
141 	}
142 
143 	if (special)
144 		c_special(fd1, file1, skip1, fd2, file2, skip2);
145 	else
146 		c_regular(fd1, file1, skip1, sb1.st_size,
147 		    fd2, file2, skip2, sb2.st_size);
148 	exit(0);
149 }
150 
151 static void
152 usage()
153 {
154 
155 	(void)fprintf(stderr,
156 	    "usage: cmp [-l | -s] file1 file2 [skip1 [skip2]]\n");
157 	exit(ERR_EXIT);
158 }
159