minix/usr.bin/grep/binary.c

   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 Coïdan Smørgrav
   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