1/*	$NetBSD: cmp.c,v 1.17 2009/04/11 12:16:12 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. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#ifndef lint
34__COPYRIGHT("@(#) Copyright (c) 1987, 1990, 1993, 1994\
35 The Regents of the University of California.  All rights reserved.");
36#endif /* not lint */
37
38#ifndef lint
39#if 0
40static char sccsid[] = "@(#)cmp.c	8.3 (Berkeley) 4/2/94";
41#else
42__RCSID("$NetBSD: cmp.c,v 1.17 2009/04/11 12:16:12 lukem Exp $");
43#endif
44#endif /* not lint */
45
46#include <sys/types.h>
47#include <sys/stat.h>
48
49#include <err.h>
50#include <errno.h>
51#include <fcntl.h>
52#include <stdio.h>
53#include <stdlib.h>
54#include <string.h>
55#include <unistd.h>
56#include <locale.h>
57
58#include "extern.h"
59
60int	lflag, sflag;
61
62__dead static void usage(void);
63
64int
65main(int argc, char *argv[])
66{
67	struct stat sb1, sb2;
68	off_t skip1 = 0, skip2 = 0;
69	int ch, fd1, fd2, special;
70	const char *file1, *file2;
71
72	setlocale(LC_ALL, "");
73
74	while ((ch = getopt(argc, argv, "ls")) != -1)
75		switch (ch) {
76		case 'l':		/* print all differences */
77			lflag = 1;
78			break;
79		case 's':		/* silent run */
80			sflag = 1;
81			break;
82		case '?':
83		default:
84			usage();
85		}
86	argv += optind;
87	argc -= optind;
88
89	if (lflag && sflag)
90		errx(ERR_EXIT, "only one of -l and -s may be specified");
91
92	if (argc < 2 || argc > 4)
93		usage();
94
95	/* Backward compatibility -- handle "-" meaning stdin. */
96	special = 0;
97	if (strcmp(file1 = argv[0], "-") == 0) {
98		special = 1;
99		fd1 = 0;
100		file1 = "stdin";
101	}
102	else if ((fd1 = open(file1, O_RDONLY, 0)) < 0) {
103		if (!sflag)
104			warn("%s", file1);
105		exit(ERR_EXIT);
106	}
107	if (strcmp(file2 = argv[1], "-") == 0) {
108		if (special)
109			errx(ERR_EXIT,
110				"standard input may only be specified once");
111		special = 1;
112		fd2 = 0;
113		file2 = "stdin";
114	}
115	else if ((fd2 = open(file2, O_RDONLY, 0)) < 0) {
116		if (!sflag)
117			warn("%s", file2);
118		exit(ERR_EXIT);
119	}
120
121	if (argc > 2) {
122		char *ep;
123
124		errno = 0;
125		skip1 = strtoq(argv[2], &ep, 0);
126		if (errno || ep == argv[2])
127			usage();
128
129		if (argc == 4) {
130			skip2 = strtoq(argv[3], &ep, 0);
131			if (errno || ep == argv[3])
132				usage();
133		}
134	}
135
136	if (!special) {
137		if (fstat(fd1, &sb1))
138			err(ERR_EXIT, "%s", file1);
139		if (!S_ISREG(sb1.st_mode))
140			special = 1;
141		else {
142			if (fstat(fd2, &sb2))
143				err(ERR_EXIT, "%s", file2);
144			if (!S_ISREG(sb2.st_mode))
145				special = 1;
146		}
147	}
148
149	if (special)
150		c_special(fd1, file1, skip1, fd2, file2, skip2);
151	else
152		c_regular(fd1, file1, skip1, sb1.st_size,
153		    fd2, file2, skip2, sb2.st_size);
154	exit(0);
155}
156
157static void
158usage(void)
159{
160
161	(void)fprintf(stderr,
162	    "usage: cmp [-l | -s] file1 file2 [skip1 [skip2]]\n");
163	exit(ERR_EXIT);
164}
165