f_seek file system API reference

f_seek()

[FreeRTOS Embedded File System API]

unsigned char f_seek( F_FILE *pxFileHandle, long lOffset, unsigned char ucWhence );

Moves the current file read/write position in an open FAT file.

Parameters:

pxFileHandle

The handle of the file in which the current file read/write position is being moved. The handle is returned from the call to f_open() used to originally open the file.

lOffset

The byte position (relative to the ucWhence parameter) to which the current file position will be moved.

ucWhence

The absolute position from which the lOffset parameter is relative. Valid values are:

Value	Description
F_SEEK_CUR	The current file position.
F_SEEK_END	The end of the file.
F_SEEK_SET	The beginning of the file.

Returns:

F_NO_ERROR

The current file read/write position was successfully moved.

Any other value

The current file read/write position was not successfully moved. The returned value holds the error code.

See also

Example usage:


void vSampleFunction( char *pcFileName, char *pcBuffer )
{
F_FILE *pxFile;

    /* Open the file specified by the pcFileName parameter. */
    pxFile = f_open( pcFileName, "r" );

    if( pxFile != NULL )
    {
        /* Read one byte from the opened file. */
        f_read( pcBuffer, 1, 1, pxFile );

        /* Move the current file position back to the very start of the file. */
        f_seek( pxFile, 0, F_SEEK_SET );

        /* Read a byte again.  As the file position was moved back to the start
        of the file the byte that is read is the same byte read by the first
        f_read() call. */
        f_read( pcBuffer, 1, 1, pxFile );

        /* This time move the current position to the very end of the file. */
        f_seek( pxFile, -1, F_SEEK_END );

        /* Now the byte read is the last byte in the file. */
        f_read( pcBuffer, 1, 1, pxFile );

        /* Finished with the file, close it. */
        f_close( pxFile );
    }
}

Example use of the f_seek() API function

The FreeRTOS Ecosystem Showcase . . . A Selection of Add-on and Complementary Products

f_seek() [FreeRTOS Embedded File System API]

The FreeRTOS Ecosystem Showcase . . .
A Selection of Add-on and Complementary Products

f_seek()

[FreeRTOS Embedded File System API]