map.c revision 75584 
1/* Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
2     Written by James Clark (jjc@jclark.com)
3
4This file is part of groff.
5
6groff is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 2, or (at your option) any later
9version.
10
11groff is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License along
17with groff; see the file COPYING.  If not, write to the Free Software
18Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
19
20#ifdef HAVE_MMAP
21
22#include <sys/types.h>
23#include <sys/mman.h>
24
25/* The Net-2 man pages says that a MAP_FILE flag is required. */
26#ifndef MAP_FILE
27#define MAP_FILE 0
28#endif
29
30char *mapread(fd, nbytes)
31     int fd;
32     int nbytes;
33{
34  char *p = (char *)mmap((caddr_t)0, (size_t)nbytes, PROT_READ,
35			 MAP_FILE|MAP_PRIVATE, fd, (off_t)0);
36  if (p == (char *)-1)
37    return 0;
38  /* mmap() shouldn't return 0 since MAP_FIXED wasn't specified. */
39  if (p == 0)
40    abort();
41  return p;
42}
43
44int unmap(p, len)
45     char *p;
46     int len;
47{
48  return munmap((caddr_t)p, len);
49}
50
51#else /* not HAVE_MMAP */
52
53#include <errno.h>
54
55char *mapread(fd, nbytes)
56     int fd;
57     int nbytes;
58{
59  errno = ENODEV;
60  return 0;
61}
62
63int unmap(p, len)
64     char *p;
65     int len;
66{
67  errno = EINVAL;
68  return -1;
69}
70
71#endif /* not HAVE_MMAP */
72