"Fossies" - the Fresh Open Source Software Archive

Member "fuse-3.10.4/doc/html/fuse-3_810_83_2example_2hello_8c.html" (9 Jun 2021, 18012 Bytes) of package /linux/misc/fuse-3.10.4.tar.xz:

Caution: In this restricted "Fossies" environment the current HTML page may not be correctly presentated and may have some non-functional links. You can here alternatively try to browse the pure source code or just view or download the uninterpreted raw source code. If the rendering is insufficient you may try to find and view the page on the project site itself.

hello.c File Reference
#include <fuse.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <assert.h>

Go to the source code of this file.

Detailed Description

minimal example filesystem using high-level API

Compile with:

gcc -Wall hello.c `pkg-config fuse3 --cflags --libs` -o hello

Source code

FUSE: Filesystem in Userspace
Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu>
This program can be distributed under the terms of the GNU GPLv2.
See the file COPYING.
#include <fuse.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <assert.h>
* Command line options
* We can't set default values for the char* fields here because
* fuse_opt_parse would attempt to free() them when the user specifies
* different values on the command line.
static struct options {
const char *filename;
const char *contents;
int show_help;
} options;
#define OPTION(t, p) \
{ t, offsetof(struct options, p), 1 }
static const struct fuse_opt option_spec[] = {
OPTION("--name=%s", filename),
OPTION("--contents=%s", contents),
OPTION("-h", show_help),
OPTION("--help", show_help),
static void *hello_init(struct fuse_conn_info *conn,
struct fuse_config *cfg)
(void) conn;
cfg->kernel_cache = 1;
return NULL;
static int hello_getattr(const char *path, struct stat *stbuf,
struct fuse_file_info *fi)
(void) fi;
int res = 0;
memset(stbuf, 0, sizeof(struct stat));
if (strcmp(path, "/") == 0) {
stbuf->st_mode = S_IFDIR | 0755;
stbuf->st_nlink = 2;
} else if (strcmp(path+1, options.filename) == 0) {
stbuf->st_mode = S_IFREG | 0444;
stbuf->st_nlink = 1;
stbuf->st_size = strlen(options.contents);
} else
res = -ENOENT;
return res;
static int hello_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
off_t offset, struct fuse_file_info *fi,
enum fuse_readdir_flags flags)
(void) offset;
(void) fi;
(void) flags;
if (strcmp(path, "/") != 0)
return -ENOENT;
filler(buf, ".", NULL, 0, 0);
filler(buf, "..", NULL, 0, 0);
filler(buf, options.filename, NULL, 0, 0);
return 0;
static int hello_open(const char *path, struct fuse_file_info *fi)
if (strcmp(path+1, options.filename) != 0)
return -ENOENT;
if ((fi->flags & O_ACCMODE) != O_RDONLY)
return -EACCES;
return 0;
static int hello_read(const char *path, char *buf, size_t size, off_t offset,
struct fuse_file_info *fi)
size_t len;
(void) fi;
if(strcmp(path+1, options.filename) != 0)
return -ENOENT;
len = strlen(options.contents);
if (offset < len) {
if (offset + size > len)
size = len - offset;
memcpy(buf, options.contents + offset, size);
} else
size = 0;
return size;
static const struct fuse_operations hello_oper = {
.init = hello_init,
.getattr = hello_getattr,
.readdir = hello_readdir,
.open = hello_open,
.read = hello_read,
static void show_help(const char *progname)
printf("usage: %s [options] <mountpoint>\n\n", progname);
printf("File-system specific options:\n"
" --name=<s> Name of the \"hello\" file\n"
" (default: \"hello\")\n"
" --contents=<s> Contents \"hello\" file\n"
" (default \"Hello, World!\\n\")\n"
int main(int argc, char *argv[])
int ret;
struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
/* Set defaults -- we have to use strdup so that
fuse_opt_parse can free the defaults if other
values are specified */
options.filename = strdup("hello");
options.contents = strdup("Hello World!\n");
/* Parse options */
if (fuse_opt_parse(&args, &options, option_spec, NULL) == -1)
return 1;
/* When --help is specified, first print our own file-system
specific help text, then signal fuse_main to show
additional help (by adding `--help` to the options again)
without usage: line (by setting argv[0] to the empty
string) */
if (options.show_help) {
assert(fuse_opt_add_arg(&args, "--help") == 0);
args.argv[0][0] = '\0';
ret = fuse_main(args.argc, args.argv, &hello_oper, NULL);
return ret;

Definition in file hello.c.