xref: /openbsd-src/usr.bin/grep/binary.c (revision 75891f45ba202082e573a03f58a61c230bb10e38)
1 /*	$OpenBSD: binary.c,v 1.20 2021/12/15 19:22:44 tb 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 <unistd.h>
34 #include <zlib.h>
35 
36 #include "grep.h"
37 
38 static int
isbinary(const char * buf,size_t n)39 isbinary(const char *buf, size_t n)
40 {
41 	return (memchr(buf, '\0', n) != NULL);
42 }
43 
44 int
bin_file(FILE * f)45 bin_file(FILE *f)
46 {
47 	char		buf[BUFSIZ];
48 	size_t		m;
49 	int		ret = 0;
50 
51 	if (fseek(f, 0L, SEEK_SET) == -1)
52 		return 0;
53 
54 	if ((m = fread(buf, 1, BUFSIZ, f)) == 0)
55 		return 0;
56 
57 	if (isbinary(buf, m))
58 		ret = 1;
59 
60 	rewind(f);
61 	return ret;
62 }
63 
64 #ifndef NOZ
65 int
gzbin_file(gzFile f)66 gzbin_file(gzFile f)
67 {
68 	char		buf[BUFSIZ];
69 	int		m;
70 	int		ret = 0;
71 
72 	if (gzseek(f, (z_off_t)0, SEEK_SET) == -1)
73 		return 0;
74 
75 	if ((m = gzread(f, buf, BUFSIZ)) <= 0)
76 		return 0;
77 
78 	if (isbinary(buf, m))
79 		ret = 1;
80 
81 	if (gzrewind(f) != 0)
82 		err(1, "gzbin_file");
83 	return ret;
84 }
85 #endif
86 
87 #ifndef SMALL
88 int
mmbin_file(mmf_t * f)89 mmbin_file(mmf_t *f)
90 {
91 	/* XXX knows too much about mmf internals */
92 	return isbinary(f->base, f->len < BUFSIZ ? f->len : BUFSIZ);
93 }
94 #endif
95