gnu/dist/groff/src/libs/libbib/map.c

   1 /*      $NetBSD$        */
   2
   3 /* Copyright (C) 1989, 1990, 1991, 1992, 2000, 2001, 2004
   4    Free Software Foundation, Inc.
   5      Written by James Clark (jjc@jclark.com)
   6
   7 This file is part of groff.
   8
   9 groff is free software; you can redistribute it and/or modify it under
  10 the terms of the GNU General Public License as published by the Free
  11 Software Foundation; either version 2, or (at your option) any later
  12 version.
  13
  14 groff is distributed in the hope that it will be useful, but WITHOUT ANY
  15 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  16 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  17 for more details.
  18
  19 You should have received a copy of the GNU General Public License along
  20 with groff; see the file COPYING.  If not, write to the Free Software
  21 Foundation, 51 Franklin St - Fifth Floor, Boston, MA 02110-1301, USA. */
  22
  23 #include <stdlib.h>
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include <config.h>
  27 #endif
  28
  29 #ifdef HAVE_MMAP
  30
  31 #include <sys/types.h>
  32 #include <sys/mman.h>
  33
  34 /* The Net-2 man pages says that a MAP_FILE flag is required. */
  35 #ifndef MAP_FILE
  36 #define MAP_FILE 0
  37 #endif
  38
  39 #ifdef __cplusplus
  40 extern "C" {
  41 #endif
  42
  43 char *mapread(int fd, int nbytes)
  44 {
  45   char *p = (char *)mmap((void *)0, (size_t)nbytes, PROT_READ,
  46                          MAP_FILE|MAP_PRIVATE, fd, (off_t)0);
  47   if (p == (char *)-1)
  48     return 0;
  49   /* mmap() shouldn't return 0 since MAP_FIXED wasn't specified. */
  50   if (p == 0)
  51     abort();
  52   return p;
  53 }
  54
  55 int unmap(char *p, int len)
  56 {
  57   return munmap((void *)p, len);
  58 }
  59
  60 #ifdef __cplusplus
  61 }
  62 #endif
  63
  64 #else /* not HAVE_MMAP */
  65
  66 #include <errno.h>
  67
  68 #ifdef __cplusplus
  69 extern "C" {
  70 #endif
  71
  72 char *mapread(int fd, int nbytes)
  73 {
  74   errno = ENODEV;
  75   return 0;
  76 }
  77
  78 int unmap(char *p, int len)
  79 {
  80   errno = EINVAL;
  81   return -1;
  82 }
  83
  84 #ifdef __cplusplus
  85 }
  86 #endif
  87
  88 #endif /* not HAVE_MMAP */