cmp.c revision 1.14 
1/*	$NetBSD: cmp.c,v 1.14 2005/02/06 20:50:34 dsl 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\n\
35	The Regents of the University of California.  All rights reserved.\n");
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 1.14 2005/02/06 20:50:34 dsl 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 <fcntl.h>
51#include <stdio.h>
52#include <stdlib.h>
53#include <string.h>
54#include <unistd.h>
55#include <locale.h>
56
57#include "extern.h"
58
59int	lflag, sflag;
60
61static void usage(void);
62
63int
64main(int argc, char *argv[])
65{
66	struct stat sb1, sb2;
67	off_t skip1, skip2;
68	int ch, fd1, fd2, special;
69	char *file1, *file2;
70
71	setlocale(LC_ALL, "");
72
73	while ((ch = getopt(argc, argv, "ls")) != -1)
74		switch (ch) {
75		case 'l':		/* print all differences */
76			lflag = 1;
77			break;
78		case 's':		/* silent run */
79			sflag = 1;
80			break;
81		case '?':
82		default:
83			usage();
84		}
85	argv += optind;
86	argc -= optind;
87
88	if (lflag && sflag)
89		errx(ERR_EXIT, "only one of -l and -s may be specified");
90
91	if (argc < 2 || argc > 4)
92		usage();
93
94	/* Backward compatibility -- handle "-" meaning stdin. */
95	special = 0;
96	if (strcmp(file1 = argv[0], "-") == 0) {
97		special = 1;
98		fd1 = 0;
99		file1 = "stdin";
100	}
101	else if ((fd1 = open(file1, O_RDONLY, 0)) < 0) {
102		if (!sflag)
103			warn("%s", file1);
104		exit(ERR_EXIT);
105	}
106	if (strcmp(file2 = argv[1], "-") == 0) {
107		if (special)
108			errx(ERR_EXIT,
109				"standard input may only be specified once");
110		special = 1;
111		fd2 = 0;
112		file2 = "stdin";
113	}
114	else if ((fd2 = open(file2, O_RDONLY, 0)) < 0) {
115		if (!sflag)
116			warn("%s", file2);
117		exit(ERR_EXIT);
118	}
119
120	skip1 = argc > 2 ? strtoq(argv[2], NULL, 10) : 0;
121	skip2 = argc == 4 ? strtoq(argv[3], NULL, 10) : 0;
122
123	if (!special) {
124		if (fstat(fd1, &sb1))
125			err(ERR_EXIT, "%s", file1);
126		if (!S_ISREG(sb1.st_mode))
127			special = 1;
128		else {
129			if (fstat(fd2, &sb2))
130				err(ERR_EXIT, "%s", file2);
131			if (!S_ISREG(sb2.st_mode))
132				special = 1;
133		}
134	}
135
136	if (special)
137		c_special(fd1, file1, skip1, fd2, file2, skip2);
138	else
139		c_regular(fd1, file1, skip1, sb1.st_size,
140		    fd2, file2, skip2, sb2.st_size);
141	exit(0);
142}
143
144static void
145usage(void)
146{
147
148	(void)fprintf(stderr,
149	    "usage: cmp [-l | -s] file1 file2 [skip1 [skip2]]\n");
150	exit(ERR_EXIT);
151}
152