FUSE

-bin
-bar
    -readme.txt
    -example
-baz
-foo
    -mv
    -test.txt

#define FUSE_USE_VERSION 26

#include <fuse.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>

static const char *bar_path ="/bar";//papka
static const char *foo_path ="/foo";//papka
static const char *bin_path ="/bin";//papka
static const char *baz_path ="/baz";//papka
static const char *example_path ="/bar/example";//file
static const char *example_str = "Hello World\n";
static const char *readmetxt_path ="/bar/readme.txt";//file
static const char *readmetxt_str = "status name surname number \n";
static const char *testtxt_path ="/foo/test.txt";
static const char *testtxt_str = "1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n11\n12\n13\n14\n15\n16\n17\n18\n19\n20\n";//file
static const char *mv_path ="/foo/mv";//file

size_t filesize(const char *filename){
     struct stat st;
     size_t retval=0;
     if(stat(filename,&st) ){
	     printf("cannot stat %s\n",filename);
     }else{
	   retval=st.st_size;
     }
     return retval;
}

static int lab5_getattr(const char *path, struct stat *stbuf)
{
	int res = 0;

	memset(stbuf, 0, sizeof(struct stat));
	if (strcmp(path, "/") == 0) {
		stbuf->st_mode = S_IFDIR | 0717;//755
		stbuf->st_nlink = 2;
	} else if (strcmp(path, bin_path) == 0) {//papka
		stbuf->st_mode = S_IFDIR | 0511;
		stbuf->st_nlink = 2;
	} else if (strcmp(path, foo_path) == 0) {//papka
		stbuf->st_mode = S_IFDIR | 0233;
		stbuf->st_nlink = 2;
	}else if (strcmp(path, bar_path) == 0) {//papka
		stbuf->st_mode = S_IFDIR | 0511;
		stbuf->st_nlink = 2;
	} else if (strcmp(path, baz_path) == 0) {//papka
		stbuf->st_mode = S_IFDIR | 0777;
		stbuf->st_nlink = 2;
	}  else if (strcmp(path, "/bin") == 0) {
		stbuf->st_mode = S_IFDIR | 0007;//144
		stbuf->st_nlink = 2;
	} else if (strcmp(path, "/baz") == 0) {//
		stbuf->st_mode = S_IFDIR | 0577;
		stbuf->st_nlink = 2;
	} else if (strcmp(path, "/foo") == 0) {//
		stbuf->st_mode = S_IFDIR | 0007;//144
		stbuf->st_nlink = 2;
	
	} else if (strcmp(path, "/bar") == 0) {
		stbuf->st_mode = S_IFDIR | 0007;//144
		stbuf->st_nlink = 2;
	} 
	else if (strcmp(path, example_path) == 0) {
		stbuf->st_mode = S_IFREG | 0222;
		stbuf->st_nlink = 1;
		stbuf->st_size = strlen(example_str);
	} else if (strcmp(path, readmetxt_path) == 0) {
		stbuf->st_mode = S_IFREG | 0444;//644
		stbuf->st_nlink = 1;
		stbuf->st_size = strlen(readmetxt_str);
	} else if (strcmp(path, testtxt_path) == 0) {
		stbuf->st_mode = S_IFREG | 0707;//0707
		stbuf->st_nlink = 1;
		stbuf->st_size = strlen(testtxt_str);
	} else if (strcmp(path, mv_path) == 0) {
		stbuf->st_mode = S_IFREG | 0777;//head
		stbuf->st_nlink = 1;
		stbuf->st_size = strlen(mv_path);
		/*size_t size = filesize("/usr/bin/mv");
		stbuf->st_size = size;*/
	} else
		res = -ENOENT;

	return res;
}

static int lab5_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
			 off_t offset, struct fuse_file_info *fi)
{
	(void) offset;
	(void) fi;

	if (strcmp(path, "/") == 0) {	
		filler(buf, ".", NULL, 0);
		filler(buf, "..", NULL, 0);
		filler(buf, bin_path + 1, NULL, 0);
        	filler(buf, bar_path + 1, NULL, 0);
		filler(buf, baz_path + 1, NULL, 0);
		filler(buf, foo_path + 1, NULL, 0);
		
	}else if (strcmp(path, bar_path) == 0) {
		filler(buf, ".", NULL, 0);
		filler(buf, "..", NULL, 0);
		filler(buf, "/readme.txt" + 1, NULL, 0);
		filler(buf, "/example" + 1, NULL, 0);
	}else if (strcmp(path, foo_path) == 0) {
		filler(buf, ".", NULL, 0);
		filler(buf, "..", NULL, 0);
		filler(buf, "/mv" + 1, NULL, 0);
		filler(buf, "/test.txt" + 1, NULL, 0);
	}
	else
		return -ENOENT;

	return 0;
}

static int lab5_open(const char *path, struct fuse_file_info *fi)
{
	if ((strcmp(path, example_path) != 0)&&(strcmp(path, readmetxt_path) != 0)&&(strcmp(path, testtxt_path) != 0)&&(strcmp(path, mv_path) != 0))
		return -ENOENT;

	if ((fi->flags & 3) != O_RDONLY)
		return -EACCES;

	return 0;
}

static int lab5_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, example_path) == 0)
	{	
		return -EACCES;
	}
	else if(strcmp(path, readmetxt_path) == 0)
	{	
		len = strlen(readmetxt_str);
		if (offset < len) {
			if (offset + size > len)
				size = len - offset;
			memcpy(buf, readmetxt_str + offset, size);
		} else
			size = 0;
		return size;
	}
	else if(strcmp(path, testtxt_path) == 0)
	{	
		len = strlen(testtxt_str);
		if (offset < len) {
			if (offset + size > len)
				size = len - offset;
			memcpy(buf, testtxt_str + offset, size);
		} else
			size = 0;
		return size;
	}
	else if(strcmp(path, mv_path) == 0)
	{
		len = filesize("/usr/bin/mv");
		FILE * f;
		f = fopen("/usr/bin/mv", "r");
		char* ptr = buf;
		while((fread(ptr, 1, 1, f)) > 0)
		{
			ptr++;
		}
		fclose(f);
		return len;
	}
	else
		return -ENOENT;
}

static struct fuse_operations hello_oper = {
	.getattr	= lab5_getattr,
	.readdir	= lab5_readdir,
	.open		= lab5_open,
	.read		= lab5_read,
};

int main(int argc, char *argv[])
{
	return fuse_main(argc, argv, &hello_oper, NULL);
}

-bar
    -readme.txt
    -example
-baz
-bin
-foo
    -mv
    -test.txt