File API

Functions
int	dfs_file_open (struct dfs_fd *fd, const char *path, int flags)
int	dfs_file_close (struct dfs_fd *fd)
int	dfs_file_ioctl (struct dfs_fd *fd, int cmd, void *args)
int	dfs_file_read (struct dfs_fd *fd, void *buf, rt_size_t len)
int	dfs_file_getdents (struct dfs_fd *fd, struct dirent *dirp, rt_size_t nbytes)
int	dfs_file_unlink (const char *path)
int	dfs_file_write (struct dfs_fd *fd, const void *buf, rt_size_t len)
int	dfs_file_flush (struct dfs_fd *fd)
int	dfs_file_lseek (struct dfs_fd *fd, rt_off_t offset)
int	dfs_file_stat (const char *path, struct stat *buf)
int	dfs_file_rename (const char *oldpath, const char *newpath)

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Function Documentation

int dfs_file_open	(	struct dfs_fd *	fd,
		const char *	path,
		int	flags
	)

this function will open a file which specified by path with specified flags.

Parameters:

fd	the file descriptor pointer to return the corresponding result.
path	the specified file path.
flags	the flags for open operator.

Returns:

0 on successful, -1 on failed.

int dfs_file_close

(

struct dfs_fd *

fd

)

this function will close a file descriptor.

Parameters:

fd	the file descriptor to be closed.

Returns:

0 on successful, -1 on failed.

int dfs_file_ioctl	(	struct dfs_fd *	fd,
		int	cmd,
		void *	args
	)

this function will perform a io control on a file descriptor.

Parameters:

fd	the file descriptor.
cmd	the command to send to file descriptor.
args	the argument to send to file descriptor.

Returns:

0 on successful, -1 on failed.

int dfs_file_read	(	struct dfs_fd *	fd,
		void *	buf,
		rt_size_t	len
	)

this function will read specified length data from a file descriptor to a buffer.

Parameters:

fd	the file descriptor.
buf	the buffer to save the read data.
len	the length of data buffer to be read.

Returns:

the actual read data bytes or 0 on end of file or failed.

int dfs_file_getdents	(	struct dfs_fd *	fd,
		struct dirent *	dirp,
		rt_size_t	nbytes
	)

this function will fetch directory entries from a directory descriptor.

Parameters:

fd	the directory descriptor.
dirp	the dirent buffer to save result.
nbytes	the available room in the buffer.

Returns:

the read dirent, others on failed.

int dfs_file_unlink

(

const char *

path

)

this function will unlink (remove) a specified path file from file system.

Parameters:

path	the specified path file to be unlinked.

Returns:

0 on successful, -1 on failed.

int dfs_file_write	(	struct dfs_fd *	fd,
		const void *	buf,
		rt_size_t	len
	)

this function will write some specified length data to file system.

Parameters:

fd	the file descriptor.
buf	the data buffer to be written.
len	the data buffer length

Returns:

the actual written data length.

int dfs_file_flush

(

struct dfs_fd *

fd

)

this function will flush buffer on a file descriptor.

Parameters:

fd	the file descriptor.

Returns:

0 on successful, -1 on failed.

int dfs_file_lseek	(	struct dfs_fd *	fd,
		rt_off_t	offset
	)

this function will seek the offset for specified file descriptor.

Parameters:

fd	the file descriptor.
offset	the offset to be seeked.

Returns:

the current position after seek.

int dfs_file_stat	(	const char *	path,
		struct stat *	buf
	)

this function will get file information.

Parameters:

path	the file path.
buf	the data buffer to save stat description.

Returns:

0 on successful, -1 on failed.

int dfs_file_rename	(	const char *	oldpath,
		const char *	newpath
	)

this function will rename an old path name to a new path name.

Parameters:

oldpath	the old path name.
newpath	the new path name.

Returns:

0 on successful, -1 on failed.