xref: /minix3/minix/usr.bin/grep/binary.c (revision d794ecc9efbcfa044947fd20468ba1f184b357e7)

/*	$OpenBSD: binary.c,v 1.18 2013/11/12 22:50:42 deraadt Exp $	*/

/*-
 * Copyright (c) 1999 James Howard and Dag-Erling Co�dan Sm�rgrav
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <ctype.h>
#include <err.h>
#include <stdio.h>
#include <string.h>
#include <zlib.h>

#include "grep.h"

static int
isbinary(const char *buf, size_t n)
{
	return (memchr(buf, '\0', n) != NULL);
}

int
bin_file(FILE *f)
{
	char		buf[BUFSIZ];
	size_t		m;
	int		ret = 0;

	if (fseek(f, 0L, SEEK_SET) == -1)
		return 0;

	if ((m = fread(buf, 1, BUFSIZ, f)) == 0)
		return 0;

	if (isbinary(buf, m))
		ret = 1;

	rewind(f);
	return ret;
}

#ifndef NOZ
int
gzbin_file(gzFile *f)
{
	char		buf[BUFSIZ];
	int		m;
	int		ret = 0;

	if (gzseek(f, (z_off_t)0, SEEK_SET) == -1)
		return 0;

	if ((m = gzread(f, buf, BUFSIZ)) <= 0)
		return 0;

	if (isbinary(buf, m))
		ret = 1;

	if (gzrewind(f) != 0)
		err(1, "gzbin_file");
	return ret;
}
#endif

#ifndef SMALL
int
mmbin_file(mmf_t *f)
{
	/* XXX knows too much about mmf internals */
	return isbinary(f->base, f->len < BUFSIZ ? f->len : BUFSIZ);
}
#endif