cmp.c revision 1.11 
1/*	$NetBSD: cmp.c,v 1.11 1997/10/18 12:55:49 lukem 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
44static char sccsid[] = "@(#)cmp.c	8.3 (Berkeley) 4/2/94";
45#else
46__RCSID("$NetBSD: cmp.c,v 1.11 1997/10/18 12:55:49 lukem 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
63int	lflag, sflag;
64
65int	main __P((int, char **));
66static void usage __P((void));
67
68int
69main(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
151static void
152usage()
153{
154
155	(void)fprintf(stderr,
156	    "usage: cmp [-l | s] file1 file2 [skip1 [skip2]]\n");
157	exit(ERR_EXIT);
158}
159