f_write

The f_write writes data to a file.

FRESULT f_write (
  FIL* fp,          /* [IN] Pointer to the file object structure */
  const void* buff, /* [IN] Pointer to the data to be written */
  UINT btw,         /* [IN] Number of bytes to write */
  UINT* bw          /* [OUT] Pointer to the variable to return number of bytes written */
);

Parameters

fp
Pointer to the open file object structure.
buff
Pointer to the data to be written.
btw
Specifies number of bytes to write in range of UINT type.
bw
Pointer to the UINT variable to return the number of bytes written. The value is always valid after the function call regardless of the result.

Return Values

FR_OK, FR_DISK_ERR, FR_INT_ERR, FR_NOT_READY, FR_INVALID_OBJECT, FR_TIMEOUT

Description

The read/write pointer of the file object advances number of bytes written. After the function succeeded, *bw should be checked to detect the disk full. In case of *bw is less than btw, it means the volume got full during the write operation. The function can take a time when the volume is full or close to full.

QuickInfo

Available when _FS_READONLY == 0.

See Also

f_open, f_read, fputc, fputs, fprintf, f_close, FIL

Return