dist/nvi/clib/mmap.c

   1 /*      $NetBSD$ */
   2
   3 #include "config.h"
   4
   5 #include <sys/types.h>
   6
   7 #include <stdlib.h>
   8 #include <unistd.h>
   9
  10 /*
  11  * This function fakes mmap() by reading `len' bytes from the file descriptor
  12  * `fd' and returning a pointer to that memory.  The "mapped" region can later
  13  * be deallocated with munmap().
  14  *
  15  * Note: ONLY reading is supported and only reading of the exact size of the
  16  * file will work.
  17  *
  18  * PUBLIC: #ifndef HAVE_MMAP
  19  * PUBLIC: char *mmap __P((char *, size_t, int, int, int, off_t));
  20  * PUBLIC: #endif
  21  */
  22 char *
  23 mmap(char *addr, size_t len, int prot, int flags, int fd, off_t off)
  24 {
  25         char *ptr;
  26
  27         if ((ptr = (char *)malloc(len)) == 0)
  28                 return ((char *)-1);
  29         if (read(fd, ptr, len) < 0) {
  30                 free(ptr);
  31                 return ((char *)-1);
  32         }
  33         return (ptr);
  34 }
  35
  36 /*
  37  * PUBLIC: #ifndef HAVE_MMAP
  38  * PUBLIC: int munmap __P((char *, size_t));
  39  * PUBLIC: #endif
  40  */
  41 int
  42 munmap(char *addr, size_t len)
  43 {
  44         free(addr);
  45         return (0);
  46 }