xref: /dragonfly/usr.bin/cmp/cmp.c (revision 984263bc)
1 /*
2  * Copyright (c) 1987, 1990, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * $FreeBSD: src/usr.bin/cmp/cmp.c,v 1.6.6.4 2001/11/21 10:47:54 dwmalone Exp $
34  *
35  */
36 
37 #ifndef lint
38 static const char copyright[] =
39 "@(#) Copyright (c) 1987, 1990, 1993, 1994\n\
40 	The Regents of the University of California.  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #ifndef lint
44 static const char sccsid[] = "@(#)cmp.c	8.3 (Berkeley) 4/2/94";
45 #endif /* not lint */
46 
47 #include <sys/types.h>
48 #include <sys/stat.h>
49 
50 #include <err.h>
51 #include <fcntl.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56 
57 #include "extern.h"
58 
59 int	lflag, sflag, xflag, zflag;
60 
61 static void usage __P((void));
62 
63 int
64 main(argc, argv)
65 	int argc;
66 	char *argv[];
67 {
68 	struct stat sb1, sb2;
69 	off_t skip1, skip2;
70 	int ch, fd1, fd2, special;
71 	const char *file1, *file2;
72 
73 	while ((ch = getopt(argc, argv, "-lsxz")) != -1)
74 		switch (ch) {
75 		case 'l':		/* print all differences */
76 			lflag = 1;
77 			break;
78 		case 's':		/* silent run */
79 			sflag = 1;
80 			zflag = 1;
81 			break;
82 		case 'x':		/* hex output */
83 			lflag = 1;
84 			xflag = 1;
85 			break;
86 		case 'z':		/* compare size first */
87 			zflag = 1;
88 			break;
89 		case '-':		/* stdin (must be after options) */
90 			--optind;
91 			goto endargs;
92 		case '?':
93 		default:
94 			usage();
95 		}
96 endargs:
97 	argv += optind;
98 	argc -= optind;
99 
100 	if (lflag && sflag)
101 		errx(ERR_EXIT, "specifying -s with -l or -x is not permitted");
102 
103 	if (argc < 2 || argc > 4)
104 		usage();
105 
106 	/* Backward compatibility -- handle "-" meaning stdin. */
107 	special = 0;
108 	if (strcmp(file1 = argv[0], "-") == 0) {
109 		special = 1;
110 		fd1 = 0;
111 		file1 = "stdin";
112 	}
113 	else if ((fd1 = open(file1, O_RDONLY, 0)) < 0) {
114 		if (!sflag)
115 			err(ERR_EXIT, "%s", file1);
116 		else
117 			exit(1);
118 	}
119 	if (strcmp(file2 = argv[1], "-") == 0) {
120 		if (special)
121 			errx(ERR_EXIT,
122 				"standard input may only be specified once");
123 		special = 1;
124 		fd2 = 0;
125 		file2 = "stdin";
126 	}
127 	else if ((fd2 = open(file2, O_RDONLY, 0)) < 0) {
128 		if (!sflag)
129 			err(ERR_EXIT, "%s", file2);
130 		else
131 			exit(1);
132 	}
133 
134 	skip1 = argc > 2 ? strtol(argv[2], NULL, 0) : 0;
135 	skip2 = argc == 4 ? strtol(argv[3], NULL, 0) : 0;
136 
137 	if (!special) {
138 		if (fstat(fd1, &sb1)) {
139 			if (!sflag)
140 				err(ERR_EXIT, "%s", file1);
141 			else
142 				exit(1);
143 		}
144 		if (!S_ISREG(sb1.st_mode))
145 			special = 1;
146 		else {
147 			if (fstat(fd2, &sb2)) {
148 				if (!sflag)
149 					err(ERR_EXIT, "%s", file2);
150 				else
151 					exit(1);
152 			}
153 			if (!S_ISREG(sb2.st_mode))
154 				special = 1;
155 		}
156 	}
157 
158 	if (special)
159 		c_special(fd1, file1, skip1, fd2, file2, skip2);
160 	else {
161 		if (zflag && sb1.st_size != sb2.st_size) {
162 			if (!sflag)
163 				(void) printf("%s %s differ: size\n",
164 				    file1, file2);
165 			exit(DIFF_EXIT);
166 		}
167 		c_regular(fd1, file1, skip1, sb1.st_size,
168 		    fd2, file2, skip2, sb2.st_size);
169 	}
170 	exit(0);
171 }
172 
173 static void
174 usage()
175 {
176 
177 	(void)fprintf(stderr,
178 	    "usage: cmp [-l | -s | -x] [-z] file1 file2 [skip1 [skip2]]\n");
179 	exit(ERR_EXIT);
180 }
181