The Contiki file system interface (CFS) defines an abstract API for reading directories and for reading and writing files.
The CFS API is intentionally simple. The CFS API is modeled after the POSIX file API, and slightly simplified.
|
| file | cfs.h |
| | CFS header file.
|
| |
Specify that cfs_open() should append written data to the file rather than overwriting it.
This constant indicates to cfs_open() that a file that should be opened for writing gets written data appended to the end of the file. The default behaviour (without CFS_APPEND) is that the file is overwritten with the new data.
- See Also
- cfs_open()
Specify that cfs_open() should open a file for reading.
This constant indicates to cfs_open() that a file should be opened for reading. CFS_WRITE should be used if the file is opened for writing, and CFS_READ + CFS_WRITE indicates that the file is opened for both reading and writing.
- See Also
- cfs_open()
Specify that cfs_seek() should compute the offset from the current position of the file pointer.
- See Also
- cfs_seek()
Specify that cfs_seek() should compute the offset from the beginning of the file.
- See Also
- cfs_seek()
Specify that cfs_open() should open a file for writing.
This constant indicates to cfs_open() that a file should be opened for writing. CFS_READ should be used if the file is opened for reading, and CFS_READ + CFS_WRITE indicates that the file is opened for both reading and writing.
- See Also
- cfs_open()
| CCIF void cfs_close |
( |
int |
fd | ) |
|
Close an open file.
- Parameters
-
| fd | The file descriptor of the open file. This function closes a file that has previously been
opened with cfs_open(). |
| CCIF void cfs_closedir |
( |
struct cfs_dir * |
dirp | ) |
|
| CCIF int cfs_open |
( |
const char * |
name, |
|
|
int |
flags |
|
) |
| |
Open a file.
- Parameters
-
| name | The name of the file. |
| flags | CFS_READ, or CFS_WRITE/CFS_APPEND, or both. |
- Returns
- A file descriptor, if the file could be opened, or -1 if the file could not be opened.
This function opens a file and returns a file descriptor for the opened file. If the file could not be opened, the function returns -1. The function can open a file for reading or writing, or both.
An opened file must be closed with cfs_close().
- See Also
- CFS_READ
-
CFS_WRITE
-
cfs_close()
| CCIF int cfs_opendir |
( |
struct cfs_dir * |
dirp, |
|
|
const char * |
name |
|
) |
| |
Open a directory for reading directory entries.
- Parameters
-
| dirp | A pointer to a struct cfs_dir that is filled in by the function. |
| name | The name of the directory. |
- Returns
- 0 or -1 if the directory could not be opened.
- See Also
- cfs_readdir()
-
cfs_closedir()
| CCIF int cfs_read |
( |
int |
fd, |
|
|
void * |
buf, |
|
|
unsigned int |
len |
|
) |
| |
Read data from an open file.
- Parameters
-
| fd | The file descriptor of the open file. |
| buf | The buffer in which data should be read from the file. |
| len | The number of bytes that should be read. |
- Returns
- The number of bytes that was actually read from the file.
This function reads data from an open file into a
buffer. The file must have first been opened with
cfs_open() and the CFS_READ flag.
Read a directory entry.
- Parameters
-
- Return values
-
| 0 | If a directory entry was read. |
| -1 | If no more directory entries can be read. |
- See Also
- cfs_opendir()
-
cfs_closedir()
| CCIF int cfs_remove |
( |
const char * |
name | ) |
|
Remove a file.
- Parameters
-
| name | The name of the file. |
- Return values
-
| 0 | If the file was removed. |
- Returns
- -1 If the file could not be removed or if it doesn't exist.
Seek to a specified position in an open file.
- Parameters
-
| fd | The file descriptor of the open file. |
| offset | A position, either relative or absolute, in the file. |
| whence | Determines how to interpret the offset parameter. |
- Returns
- The new position in the file, or (cfs_offset_t)-1 if the seek failed.
This function moves the file position to the specified
position in the file. The next byte that is read from
or written to the file will be at the position given
determined by the combination of the offset parameter
and the whence parameter.
- See Also
- CFS_SEEK_CUR
-
CFS_SEEK_END
-
CFS_SEEK_SET
| CCIF int cfs_write |
( |
int |
fd, |
|
|
const void * |
buf, |
|
|
unsigned int |
len |
|
) |
| |
Write data to an open file.
- Parameters
-
| fd | The file descriptor of the open file. |
| buf | The buffer from which data should be written to the file. |
| len | The number of bytes that should be written. |
- Returns
- The number of bytes that was actually written to the file.
This function reads writes data from a memory buffer to
an open file. The file must have been opened with
cfs_open() and the CFS_WRITE flag.
1.8.5