/contrib/groff/src/libs/libbib/map.c

 1/* Copyright (C) 1989, 1990, 1991, 1992, 2000, 2001, 2004
 2   Free Software Foundation, Inc.
 3     Written by James Clark (jjc@jclark.com)
 4
 5This file is part of groff.
 6
 7groff is free software; you can redistribute it and/or modify it under
 8the terms of the GNU General Public License as published by the Free
 9Software Foundation; either version 2, or (at your option) any later
10version.
11
12groff is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
15for more details.
16
17You should have received a copy of the GNU General Public License along
18with groff; see the file COPYING.  If not, write to the Free Software
19Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA. */
20
21#include <stdlib.h>
22
23#ifdef HAVE_CONFIG_H
24#include <config.h>
25#endif
26
27#ifdef HAVE_MMAP
28
29#include <sys/types.h>
30#include <sys/mman.h>
31
32/* The Net-2 man pages says that a MAP_FILE flag is required. */
33#ifndef MAP_FILE
34#define MAP_FILE 0
35#endif
36
37#ifdef __cplusplus
38extern "C" {
39#endif
40
41char *mapread(int fd, int nbytes)
42{
43  char *p = (char *)mmap((void *)0, (size_t)nbytes, PROT_READ,
44			 MAP_FILE|MAP_PRIVATE, fd, (off_t)0);
45  if (p == (char *)-1)
46    return 0;
47  /* mmap() shouldn't return 0 since MAP_FIXED wasn't specified. */
48  if (p == 0)
49    abort();
50  return p;
51}
52
53int unmap(char *p, int len)
54{
55  return munmap((void *)p, len);
56}
57
58#ifdef __cplusplus
59}
60#endif
61
62#else /* not HAVE_MMAP */
63
64#include <errno.h>
65
66#ifdef __cplusplus
67extern "C" {
68#endif
69
70char *mapread(int fd, int nbytes)
71{
72  errno = ENODEV;
73  return 0;
74}
75
76int unmap(char *p, int len)
77{
78  errno = EINVAL;
79  return -1;
80}
81
82#ifdef __cplusplus
83}
84#endif
85
86#endif /* not HAVE_MMAP */