example/null.c

   1 /*
   2   FUSE: Filesystem in Userspace
   3   Copyright (C) 2001-2007  Miklos Szeredi <miklos@szeredi.hu>
   4
   5   This program can be distributed under the terms of the GNU GPL.
   6   See the file COPYING.
   7
   8   gcc -Wall null.c `pkg-config fuse --cflags --libs` -o null
   9 */
  10
  11 #define FUSE_USE_VERSION 26
  12
  13 #include <fuse.h>
  14 #include <string.h>
  15 #include <unistd.h>
  16 #include <time.h>
  17 #include <errno.h>
  18
  19 static int null_getattr(const char *path, struct stat *stbuf)
  20 {
  21         if(strcmp(path, "/") != 0)
  22                 return -ENOENT;
  23
  24         stbuf->st_mode = S_IFREG | 0644;
  25         stbuf->st_nlink = 1;
  26         stbuf->st_uid = getuid();
  27         stbuf->st_gid = getgid();
  28         stbuf->st_size = (1ULL << 32); /* 4G */
  29         stbuf->st_blocks = 0;
  30         stbuf->st_atime = stbuf->st_mtime = stbuf->st_ctime = time(NULL);
  31
  32         return 0;
  33 }
  34
  35 static int null_truncate(const char *path, off_t size)
  36 {
  37         (void) size;
  38
  39         if(strcmp(path, "/") != 0)
  40                 return -ENOENT;
  41
  42         return 0;
  43 }
  44
  45 static int null_open(const char *path, struct fuse_file_info *fi)
  46 {
  47         (void) fi;
  48
  49         if(strcmp(path, "/") != 0)
  50                 return -ENOENT;
  51
  52         return 0;
  53 }
  54
  55 static int null_read(const char *path, char *buf, size_t size,
  56                      off_t offset, struct fuse_file_info *fi)
  57 {
  58         (void) buf;
  59         (void) offset;
  60         (void) fi;
  61
  62         if(strcmp(path, "/") != 0)
  63                 return -ENOENT;
  64
  65         if (offset >= (1ULL << 32))
  66                 return 0;
  67
  68         return size;
  69 }
  70
  71 static int null_write(const char *path, const char *buf, size_t size,
  72                       off_t offset, struct fuse_file_info *fi)
  73 {
  74         (void) buf;
  75         (void) offset;
  76         (void) fi;
  77
  78         if(strcmp(path, "/") != 0)
  79                 return -ENOENT;
  80
  81         return size;
  82 }
  83
  84 static struct fuse_operations null_oper = {
  85         .getattr        = null_getattr,
  86         .truncate       = null_truncate,
  87         .open           = null_open,
  88         .read           = null_read,
  89         .write          = null_write,
  90 };
  91
  92 int main(int argc, char *argv[])
  93 {
  94         return fuse_main(argc, argv, &null_oper, NULL);
  95 }