Data Structures
struct	dirent
	Directory entry struct written by readdir(). More...

struct	input_stream_from_file
	Concrete struct for a file input stream. More...

struct	ltrx_statfs
	Contains file system statistics. More...

struct	output_stream_to_file
	Concrete struct for a file output stream. More...

Macros
#define	DT_CHR 2
	Directory entry type character device.

#define	DT_DIR 4
	Directory entry type directory.

#define	DT_REG 8
	Directory entry type regular file.

Typedefs
typedef void	DIR
	Directory stream type. More...

Enumerations
enum	ltrx_fs_bank { LTRX_FS_BANK__A = 1, LTRX_FS_BANK__B = 2 }
	Bank in the file system. More...

Functions
int	access (const char *path, int flags)
	Check permissions. More...

int	close (int fd)
	Close a file. More...

int	closedir (DIR *dir)
	Close a directory stream. More...

int	dirfd (DIR *dir)
	Extract the file descriptor used by a DIR stream. More...

int	fstat (int fd, struct stat *st)
	Get file status. More...

int	fstatat (int fd, const char path, struct stat st, int flag)
	Get file status relative to directory file descriptor. More...

int	fsync (int fd)
	Synchronize changes to a file. More...

off_t	lseek (int fd, off_t offset, int whence)
	Move the read/write file offset. More...

void	ltrx_fs_compact (void)
	Compact the file system. More...

void	ltrx_fs_format (bool all)
	Format the file system. More...

bool	ltrx_input_stream_init_from_file (struct input_stream_from_file inStream, const char fileName)
	Set up an input stream from a file. More...

bool	ltrx_output_stream_init_to_file (struct output_stream_to_file outStream, const char fileName)
	Set up an output stream to a file. More...

int	mkdir (const char *path, mode_t mode)
	Create directory. More...

int	mkdirat (int cwdfd, const char *path, mode_t mode)
	Create directory relative to directory descriptor. More...

int	open (const char *path, int flags,...)
	Open a file. More...

int	openat (int fd, const char *path, int flags,...)
	Open a file relative to directory file descriptor. More...

DIR *	opendir (const char *path)
	Open a directory stream. More...

int	read (int fd, void *buffer, size_t nbytes)
	Read from a file. More...

int	readdir (DIR dir, struct dirent dent)
	Read a directory. More...

int	rename (const char oldname, const char newname)
	Change a file's name. More...

int	renameat (int oldfd, const char oldname, int newfd, const char newname)
	Change a file's name. More...

int	rmdir (const char *path)
	Delete a directory. More...

int	stat (const char fname, struct stat st)
	Get file status. More...

int	unlink (const char *path)
	Delete a file. More...

int	unlinkat (int cwdfd, const char *path, int flags)
	Delete a file or directory. More...

int	write (int fd, const void *buffer, size_t nbytes)
	Write to a file. More...

Detailed Description

File System contains the definitions for accessing files.

NOTE: This file system does not maintain a "current working directory". If your path is or might be relative, open() will implicitly use the root directory as its base. Use openat() to select an explicit base directory.

Here are the implicit and explicit versions of functions in the SDK:

Implicit	Explicit
open()	openat()
stat()	fstatat()
mkdir()	mkdirat()
rename()	renameat()
unlink(), rmdir()	unlinkat()
opendir()	N/A

Typedef Documentation

typedef void DIR

Directory stream type.

Typedef DIR is a stream opened by opendir(), read by readdir(), and closed by closedir().

Enumeration Type Documentation

enum ltrx_fs_bank

Bank in the file system.

Enumerator
LTRX_FS_BANK__A	Bank A.
LTRX_FS_BANK__B	Bank B.

Function Documentation

int access	(	const char *	path,
		int	flags
	)

Check permissions.

Check the file or directory named by path.

Return values

0	Success.
-1	Denied.

Parameters

[in]	path	The pathname.
[in]	flags	Use `F_OK` to test for existence. Use `R_OK` to test for read permission. Use `W_OK` to test for write permission. Multiple flags can be bitwise or'ed.

int close ( int fd )

Close a file.

Closing a file frees up the file descriptor.

Return values

0	Success.
-1	Error, see `errno`.

Parameters

[in] fd File descriptor to close.

int closedir ( DIR * dir )

Close a directory stream.

Close a directory.

Closes a directory designated by dir. If a file descriptor has been extracted by dirfd(), it is also closed.

Return values

0	Success.
-1	Error, see `errno`.

Close the directory stream assocated with the dir argument. A successful to closedir() also closes the underlying file descriptor associated with dir.

Returns: 0 Success

Return values

-1	Error, see `errno`.

Parameters

[in,out] dir An object of type DIR to be closed.

int dirfd ( DIR * dir )

Extract the file descriptor used by a DIR stream.

Return a file descriptor referring to the same directory as the dir argument. This file descriptor shall be closed by a call to closedir().

Returns: File descriptor.

Return values

-1	Error, see `errno`.

Parameters

[in] dir Pointer from opendir().

int fstat	(	int	fd,
		struct stat *	st
	)

Get file status.

Obtain information about file fd, writing it to the structure st.

Return values

0	Success.
-1	Error, see `errno`.

Parameters

[in]	fd	File descriptor to obtain information for.
[out]	st	Structure to receive the information.

int fstatat	(	int	fd,
		const char *	path,
		struct stat *	st,
		int	flag
	)

Get file status relative to directory file descriptor.

Obtain information about file fd, writing it to the structure st.

Return values

0	Success.
-1	Error, see `errno`.

Parameters

[in]	fd	File descriptor whose associated directory is to be used if the path is relative.
[in]	path	Directory and file pathname.
[out]	st	Structure to receive the information.
[in]	flag	flag – UNUSED.

int fsync ( int fd )

Synchronize changes to a file.

Requests that all data for fd is to be transferred to Flash. It will not return until the transfer is complete or an error is detected.

Return values

0	Success.
-1	Error, see `errno`.

Parameters

[in] fd File descriptor to synchronize.

off_t lseek	(	int	fd,
		off_t	offset,
		int	whence
	)

Move the read/write file offset.

Sets the file offset for the designated file according to the value of whence:

SEEK_SET: The file offset shall be set to offset bytes.
SEEK_CUR: The file offset shall be set to its current location plus offset.
SEEK_END: The file offset shall be set to the size of the file plus offset.

Returns: The resulting offset.

Return values

-1	Error, see `errno`.

Parameters

[in]	fd	File descriptor to seek.
[in]	offset	Offset value in bytes. Can be positive or negative.
[in]	whence	How to apply offset, as described above.

void ltrx_fs_compact ( void )

Compact the file system.

Preserves all files in the file system. Erases the unused bank of the file system and copies only the "clean" data into that bank. This frees up "dirty" space in the file system.

"Dirty" space results when a file or directory is deleted.

void ltrx_fs_format ( bool all )

Format the file system.

Removes directories and files from both banks of the file system.

Parameters

[in] all If true, absolutely everything is removed. if false, system files are preserved; "/.hidden.*".

bool ltrx_input_stream_init_from_file	(	struct input_stream_from_file *	inStream,
		const char *	fileName
	)

Set up an input stream from a file.

Return values

true	Success.
false	Failed.

Parameters

[out]	inStream	Your file input stream struct to initialize.
[in]	fileName	The full path name of the desired file.

bool ltrx_output_stream_init_to_file	(	struct output_stream_to_file *	outStream,
		const char *	fileName
	)

Set up an output stream to a file.

Return values

true	Success.
false	Failed.

Parameters

[out]	outStream	Your file output stream struct to initialize.
[in]	fileName	The full path name of the desired file.

int mkdir	(	const char *	path,
		mode_t	mode
	)

Create directory.

Creates a directory at the designated path.

Return values

0	Success.
-1	Error, see `errno`.

Parameters

[in]	path	Directory pathname.
[in]	mode	Mode, unused, present for compatibility (set to 0).

int mkdirat	(	int	cwdfd,
		const char *	path,
		mode_t	mode
	)

Create directory relative to directory descriptor.

Creates a directory at the designated path.

Return values

0	Success.
-1	Error, see `errno`.

Parameters

[in]	cwdfd	Directory descriptor is to be used if the path is relative.
[in]	path	Directory pathname.
[in]	mode	Mode, unused, present for compatibility (set to 0).

int open	(	const char *	path,
		int	flags,
			...
	)

Open a file.

When opening a file, the flags govern the mode of operation:

O_APPEND: If set, the file offset shall be set to the end of the file prior to each write.
O_CREAT: If the file exists, this flag has no effect except as noted under O_EXCL below. Otherwise, the file shall be created.
O_DIRECTORY: If path resolves to a non-directory file, fail and set errno to ENOTDIR.
O_EXCL: If O_CREAT and O_EXCL are set, open() shall fail if the file exists. The check for the existence of the file and the creation of the file if it does not exist shall be atomic with respect to other threads executing open() naming the same filename in the same directory with O_EXCL and O_CREAT set. If O_EXCL is set and O_CREAT is not set, the result is undefined.
O_RDONLY: Open for reading only.
O_RDWR: Open for reading and writing.
O_TRUNC: If the file exists and is a regular file, and the file is successfully opened O_RDWR or O_WRONLY, its length shall be truncated to 0.
O_WRONLY: Open for writing only.

Returns: File descriptor.

Return values

-1	Error, see `errno`.

Parameters

[in]	path	Directory and file pathname.
[in]	flags	One or more flags combined with bitwise-inclusive OR.

int openat	(	int	fd,
		const char *	path,
		int	flags,
			...
	)

Open a file relative to directory file descriptor.

When opening a file, the flags govern the mode of operation:

O_APPEND: If set, the file offset shall be set to the end of the file prior to each write.
O_CREAT: If the file exists, this flag has no effect except as noted under O_EXCL below. Otherwise, the file shall be created.
O_DIRECTORY: If path resolves to a non-directory file, fail and set errno to ENOTDIR.
O_EXCL: If O_CREAT and O_EXCL are set, open() shall fail if the file exists. The check for the existence of the file and the creation of the file if it does not exist shall be atomic with respect to other threads executing open() naming the same filename in the same directory with O_EXCL and O_CREAT set. If O_EXCL is set and O_CREAT is not set, the result is undefined.
O_RDONLY: Open for reading only.
O_RDWR: Open for reading and writing.
O_TRUNC: If the file exists and is a regular file, and the file is successfully opened O_RDWR or O_WRONLY, its length shall be truncated to 0.
O_WRONLY: Open for writing only.

Returns: File descriptor.

Return values

-1	Error, see `errno`.

Parameters

[in]	fd	File descriptor whose associated directory is to be used if the path is relative.
[in]	path	Directory and file pathname.
[in]	flags	One or more flags combined with bitwise-inclusive OR.

DIR * opendir ( const char * path )

Open a directory stream.

Open a directory.

Opens a directory stream corresponding to the directory named by path. The directory stream is positioned at the first entry.

Returns: Pointer to an object of type DIR.

Return values

NULL	Error, see `errno`.

Open a directory stream corresponding to the directory path, and return a pointer to the directory stream. The stream is positioned at the first entry in the directory.

Returns: Pointer to the directory stream.

Return values

NULL	Error, see `errno`.

Parameters

[in] path Directory pathname.

int read	(	int	fd,
		void *	buffer,
		size_t	nbytes
	)

Read from a file.

Reads data from the designated file.

Returns: Number of bytes actually read.

Return values

-1	Error, see `errno`.

Parameters

[in]	fd	File descriptor to read.
[out]	buffer	Buffer to be written with data.
[in]	nbytes	Maximum number of bytes to read into buffer.

int readdir	(	DIR *	dir,
		struct dirent *	dent
	)

Read a directory.

Reads a directory stream dir at its current position. The directory stream is positioned at the next entry.

Return values

0	Success.
-1	Error, see `errno`.

Return a pointer to a dirent structure representing the next directory entry in the directory stream pointed to by dirp. Return NULL on reaching the end of the directory stream or if an error occurs.

Returns: Pointer to the directory stream.

Return values

NULL	Error, see `errno`.

Parameters

[in,out]	dir	An object of type `DIR` to be read.
[out]	dent	Structure to receive the information.

int rename	(	const char *	oldname,
		const char *	newname
	)

Change a file's name.

Finds the file with oldname, then renames it to newname.

Return values

0	Success.
-1	Error, see `errno`.

Parameters

[in]	oldname	The original name.
[in]	newname	The new name.

int renameat	(	int	oldfd,
		const char *	oldname,
		int	newfd,
		const char *	newname
	)

Change a file's name.

Finds the file with oldname, then renames it to newname.

Return values

0	Success.
-1	Error, see `errno`.

Parameters

[in]	oldfd	File descriptor whose associated directory is to be used if the oldname is relative.
[in]	oldname	File to look for.
[in]	newfd	File descriptor whose associated directory is to be used if the newname is relative.
[in]	newname	New name for the file.

int rmdir ( const char * path )

Delete a directory.

Deletes the directory named by path.

Return values

0	Success.
-1	Error, see `errno`.

Parameters

[in] path Directory pathname.

int stat	(	const char *	fname,
		struct stat *	st
	)

Get file status.

Obtain information about the named file, writing it to the structure st.

Return values

0	Success.
-1	Error, see `errno`.

Parameters

[in]	fname	Directory and file pathname.
[out]	st	Structure to receive the information.

int unlink ( const char * path )

Delete a file.

Deletes the file named by path.

Return values

0	Success.
-1	Error, see `errno`.

Parameters

[in] path Directory and file pathname.

int unlinkat	(	int	cwdfd,
		const char *	path,
		int	flags
	)

Delete a file or directory.

Deletes the file or directory named by path.

Return values

0	Success.
-1	Error, see `errno`.

Parameters

[in]	cwdfd	File descriptor whose associated directory is to be used if the path is relative.
[in]	path	The pathname.
[in]	flags	Use `AT_REMOVEDIR` to remove a directory, or `0` to remove a file.

int write	(	int	fd,
		const void *	buffer,
		size_t	nbytes
	)

Write to a file.

Writes data to the designated file.

Returns: Number of bytes actually written.

Return values

-1	Error, see `errno`.

Parameters

[in]	fd	File descriptor to write.
[in]	buffer	Buffer supplying data to be written.
[in]	nbytes	Maximum number of bytes to write into the file.

Data Structures

Macros

Typedefs

Enumerations

Functions

Detailed Description

Typedef Documentation

Enumeration Type Documentation

Function Documentation