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/*
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FUSE: Filesystem in Userspace
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Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu>
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This program can be distributed under the terms of the GNU GPLv2.
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See the file COPYING.
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*/
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/** @file
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*
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* minimal example filesystem using high-level API
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*
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* Compile with:
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*
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* gcc -Wall hello.c `pkg-config fuse3 --cflags --libs` -o hello
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*
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* ## Source code ##
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* \include hello.c
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*/
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#define FUSE_USE_VERSION 31
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#include <fuse.h>
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#include <stdio.h>
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#include <string.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <stddef.h>
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#include <assert.h>
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/*
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* Command line options
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*
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* We can't set default values for the char* fields here because
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* fuse_opt_parse would attempt to free() them when the user specifies
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* different values on the command line.
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*/
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static struct options {
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const char *filename;
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const char *contents;
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int show_help;
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} options;
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#define OPTION(t, p) \
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{ t, offsetof(struct options, p), 1 }
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static const struct fuse_opt option_spec[] = {
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OPTION("--name=%s", filename),
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OPTION("--contents=%s", contents),
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OPTION("-h", show_help),
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OPTION("--help", show_help),
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FUSE_OPT_END
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};
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static void *hello_init(struct fuse_conn_info *conn,
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struct fuse_config *cfg)
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{
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(void) conn;
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cfg->kernel_cache = 1;
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return NULL;
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}
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static int hello_getattr(const char *path, struct stat *stbuf,
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struct fuse_file_info *fi)
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{
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fprintf(stderr, "hello_getattr sleeping...\n");
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sleep(2);
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fprintf(stderr, "hello_getattr woke up!\n");
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(void) fi;
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int res = 0;
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memset(stbuf, 0, sizeof(struct stat));
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if (strcmp(path, "/") == 0) {
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stbuf->st_mode = S_IFDIR | 0755;
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stbuf->st_nlink = 2;
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} else if (strcmp(path+1, options.filename) == 0) {
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stbuf->st_mode = S_IFREG | 0444;
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stbuf->st_nlink = 1;
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stbuf->st_size = strlen(options.contents);
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} else
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res = -ENOENT;
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return res;
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}
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static int hello_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
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off_t offset, struct fuse_file_info *fi,
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enum fuse_readdir_flags flags)
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{
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(void) offset;
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(void) fi;
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(void) flags;
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if (strcmp(path, "/") != 0)
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return -ENOENT;
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fprintf(stderr, "hello_readdir sleeping...\n");
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sleep(2);
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fprintf(stderr, "hello_readdir woke up!\n");
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filler(buf, ".", NULL, 0, FUSE_FILL_DIR_DEFAULTS);
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filler(buf, "..", NULL, 0, FUSE_FILL_DIR_DEFAULTS);
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filler(buf, options.filename, NULL, 0, FUSE_FILL_DIR_DEFAULTS);
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return 0;
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}
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static int hello_open(const char *path, struct fuse_file_info *fi)
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{
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if (strcmp(path+1, options.filename) != 0)
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return -ENOENT;
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if ((fi->flags & O_ACCMODE) != O_RDONLY)
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return -EACCES;
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return 0;
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}
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static int hello_read(const char *path, char *buf, size_t size, off_t offset,
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struct fuse_file_info *fi)
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{
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size_t len;
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(void) fi;
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if(strcmp(path+1, options.filename) != 0)
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return -ENOENT;
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len = strlen(options.contents);
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if (offset < len) {
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if (offset + size > len)
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size = len - offset;
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memcpy(buf, options.contents + offset, size);
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} else
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size = 0;
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return size;
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}
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static int hello_opendir(const char *path, struct fuse_file_info *fi) {
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fprintf(stderr, "hello_opendir sleeping...\n");
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sleep(2);
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fprintf(stderr, "hello_opendir woke up!\n");
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return 0;
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}
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static int hello_access(const char *, int) {
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fprintf(stderr, "hello_access sleeping...\n");
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sleep(2);
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fprintf(stderr, "hello_access woke up!\n");
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return 0;
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}
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static const struct fuse_operations hello_oper = {
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.init = hello_init,
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.getattr = hello_getattr,
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.readdir = hello_readdir,
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.open = hello_open,
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.read = hello_read,
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.opendir = hello_opendir,
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.access = hello_access,
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};
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static void show_help(const char *progname)
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{
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printf("usage: %s [options] <mountpoint>\n\n", progname);
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printf("File-system specific options:\n"
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" --name=<s> Name of the \"hello\" file\n"
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" (default: \"hello\")\n"
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" --contents=<s> Contents \"hello\" file\n"
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" (default \"Hello, World!\\n\")\n"
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"\n");
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}
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int main(int argc, char *argv[])
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{
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int ret;
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struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
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/* Set defaults -- we have to use strdup so that
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fuse_opt_parse can free the defaults if other
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values are specified */
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options.filename = strdup("hello");
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options.contents = strdup("Hello World!\n");
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/* Parse options */
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if (fuse_opt_parse(&args, &options, option_spec, NULL) == -1)
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return 1;
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/* When --help is specified, first print our own file-system
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specific help text, then signal fuse_main to show
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additional help (by adding `--help` to the options again)
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without usage: line (by setting argv[0] to the empty
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string) */
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if (options.show_help) {
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show_help(argv[0]);
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assert(fuse_opt_add_arg(&args, "--help") == 0);
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args.argv[0][0] = '\0';
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}
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ret = fuse_main(args.argc, args.argv, &hello_oper, NULL);
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fuse_opt_free_args(&args);
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return ret;
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}
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