xref: /minix3/minix/usr.bin/grep/binary.c (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1 /*	$OpenBSD: binary.c,v 1.18 2013/11/12 22:50:42 deraadt Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999 James Howard and Dag-Erling Co�dan Sm�rgrav
5  * 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  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <ctype.h>
30 #include <err.h>
31 #include <stdio.h>
32 #include <string.h>
33 #include <zlib.h>
34 
35 #include "grep.h"
36 
37 static int
38 isbinary(const char *buf, size_t n)
39 {
40 	return (memchr(buf, '\0', n) != NULL);
41 }
42 
43 int
44 bin_file(FILE *f)
45 {
46 	char		buf[BUFSIZ];
47 	size_t		m;
48 	int		ret = 0;
49 
50 	if (fseek(f, 0L, SEEK_SET) == -1)
51 		return 0;
52 
53 	if ((m = fread(buf, 1, BUFSIZ, f)) == 0)
54 		return 0;
55 
56 	if (isbinary(buf, m))
57 		ret = 1;
58 
59 	rewind(f);
60 	return ret;
61 }
62 
63 #ifndef NOZ
64 int
65 gzbin_file(gzFile *f)
66 {
67 	char		buf[BUFSIZ];
68 	int		m;
69 	int		ret = 0;
70 
71 	if (gzseek(f, (z_off_t)0, SEEK_SET) == -1)
72 		return 0;
73 
74 	if ((m = gzread(f, buf, BUFSIZ)) <= 0)
75 		return 0;
76 
77 	if (isbinary(buf, m))
78 		ret = 1;
79 
80 	if (gzrewind(f) != 0)
81 		err(1, "gzbin_file");
82 	return ret;
83 }
84 #endif
85 
86 #ifndef SMALL
87 int
88 mmbin_file(mmf_t *f)
89 {
90 	/* XXX knows too much about mmf internals */
91 	return isbinary(f->base, f->len < BUFSIZ ? f->len : BUFSIZ);
92 }
93 #endif
94