File System API

Detailed Description

The FNET File System (FS) API provides standard interface for file and directory manipulations.
The FNET File System API is inspired by standard ANSI C and POSIX-based APIs.
The following table summarizes the supported File System API functions:

File System API

Functions	Description
fnet_fs_init(), fnet_fs_release()	FNET file system interface initialization/release.
fnet_fs_mount(), fnet_fs_unmount()	Mount/unmount a file system image.
fnet_fs_fopen(), fnet_fs_fopen_re(), fnet_fs_fclose()	Open/close a file.
fnet_fs_fread(), fnet_fs_fgetc()	Read a file.
fnet_fs_rewind(), fnet_fs_fseek(), fnet_fs_feof(), fnet_fs_ftell()	Move/get a file pointer.
fnet_fs_opendir(), fnet_fs_closedir()	Open/close a directory.
fnet_fs_readdir(), fnet_fs_rewinddir()	Read a directory.

The path name that points to a file or directory has the following format:

/[mount name][/directory name]..[/file name] 

After the FS is initialized by calling the fnet_fs_init() function, a user application should call a FS registration function (for example the fnet_fs_rom_register() for the FNET ROM FS registration), and finally mount a FS image by the fnet_fs_mount() function. Thereafter an application has access to files and directories on the mounted FS image.

For example:

...
// FNET FS initialization.
if( fnet_fs_init( ) == FNET_OK)
{
   // Register ROM FS.
   fnet_fs_rom_register( );

   // Mount ROM FS image.
   if( fnet_fs_mount( FNET_FS_ROM_NAME, "rom", (void *)&fnet_fs_image ) == FNET_ERR )
          fnet_println("ERROR: FS image mount is failed!");
   ...

   // Print directory content.
   {
      fnet_fs_dirent_t ep;
      fnet_fs_dir_t dir;
      fnet_uint8_t name[FNET_CFG_FS_MOUNT_NAME_MAX+1];

      // Open dir.
      dir = fnet_fs_opendir("\rom");

      if (dir)
      {
          fnet_memset(&ep, 0, sizeof(fnet_fs_dirent_t) );
          ep.d_name = name;
          ep.d_name_size = sizeof(name);

          // Print the dir content.
          while ((fnet_fs_readdir (dir, &ep))==FNET_OK)
              fnet_println ("%7s  -  %s", (ep.d_type == DT_DIR)?"<DIR>":"<FILE>",ep.d_name);

          // Close dir.
          fnet_fs_closedir(dir);
      }
      else
          fnet_println("ERROR: The directory is failed!");
   }
   ...
}
else
{
   fnet_println("ERROR: FNET FS initialization is failed!");
}
...

Configuration parameters:

• FNET_CFG_FS
• FNET_CFG_FS_MOUNT_MAX
• FNET_CFG_FS_MOUNT_NAME_MAX
• FNET_CFG_FS_DESC_MAX

Modules
	ROM File System API

Data Structures
struct	fnet_fs_dirent_t
	This structure is used by the fnet_fs_finfo() and the fnet_fs_readdir() function to get information about directory entries (files or directories). More...

Macros
#define	FNET_FS_SPLITTER
	File-path splitter. This symbol is used to delimit directories and files in a pathname string. More...
#define	FNET_FS_EOF
	End-of-file condition. This is a condition, where no data can be read from a data source. More...

Typedefs
typedef void *	fnet_fs_dir_t
	Directory descriptor. This is the abstract key for accessing a directory. More...
typedef void *	fnet_fs_file_t
	File descriptor. This is the abstract key for accessing a file. More...

Enumerations
enum	fnet_fs_seek_origin_t {   FNET_FS_SEEK_SET,   FNET_FS_SEEK_CUR,   FNET_FS_SEEK_END }
	Origin position. Used by fnet_fs_fseek() function. More...
enum	fnet_fs_d_type_t {   DT_UNKNOWN,   DT_REG,   DT_DIR }
	Directory entry type. More...

Functions
fnet_return_t	fnet_fs_init (void)
	Initializes the FNET File System Interface. More...
void	fnet_fs_release (void)
	Releases the FNET File System Interface. More...
fnet_return_t	fnet_fs_mount (fnet_char_t *fs_name, const fnet_char_t *mount_name, const void *arg)
	Mounts a file system. More...
fnet_return_t	fnet_fs_unmount (const fnet_char_t *mount_name)
	Unmounts a file system. More...
fnet_fs_dir_t	fnet_fs_opendir (const fnet_char_t *dirname)
	Opens a directory descriptor. More...
fnet_return_t	fnet_fs_closedir (fnet_fs_dir_t dir)
	Closes a directory descriptor. More...
fnet_return_t	fnet_fs_readdir (fnet_fs_dir_t dir, fnet_fs_dirent_t *dirent)
	Reads a directory entry. More...
void	fnet_fs_rewinddir (fnet_fs_dir_t dir)
	Resets a directory position. More...
fnet_fs_file_t	fnet_fs_fopen (const fnet_char_t *filename, const fnet_char_t *mode)
	Opens a file descriptor. More...
fnet_fs_file_t	fnet_fs_fopen_re (const fnet_char_t *filename, const fnet_char_t *mode, fnet_fs_dir_t dir)
	Opens a file relatively in an opened directory. More...
fnet_return_t	fnet_fs_fclose (fnet_fs_file_t file)
	Closes a file descriptor. More...
fnet_size_t	fnet_fs_fread (void *buf, fnet_size_t size, fnet_fs_file_t file)
	Reads data from a file. More...
void	fnet_fs_rewind (fnet_fs_file_t file)
	Resets a file position. More...
fnet_bool_t	fnet_fs_feof (fnet_fs_file_t file)
	Checks the End-of-File indicator. More...
fnet_int32_t	fnet_fs_fgetc (fnet_fs_file_t file)
	Gets a character from a file. More...
fnet_return_t	fnet_fs_fseek (fnet_fs_file_t file, fnet_int32_t offset, fnet_fs_seek_origin_t origin)
	Changes the file-position indicator for the specified file. More...
fnet_int32_t	fnet_fs_ftell (fnet_fs_file_t file)
	Gets the current position in a file. More...
fnet_return_t	fnet_fs_finfo (fnet_fs_file_t file, fnet_fs_dirent_t *dirent)
	Gets a file information. More...