f_read

The f_read function reads data from a file.

FRESULT f_read (
  FIL* fp,     /* [IN] File object */
  void* buff,  /* [OUT] Buffer to store read data */
  UINT btr,    /* [IN] Number of bytes to read */
  UINT* br     /* [OUT] Number of bytes read */
);

Parameters

fp
Pointer to the open file object.
buff
Pointer to the buffer to store read data.
btr
Number of bytes to read in range of UINT type.
br
Pointer to the UINT variable to return number of bytes read. The value is always valid after the function call regardless of the result code.

Return Values

FR_OK, FR_DISK_ERR, FR_INT_ERR, FR_INVALID_OBJECT, FR_TIMEOUT

Description

The function starts to read data from the file at the position pointed by the read/write pointer. The read/write pointer advances as number of bytes read. After the function succeeded, *br should be checked to detect end of the file. In case of *br < btr, it means the read/write pointer reached end of the file during read operation.

QuickInfo

Always available.

See Also

f_open, fgets, f_write, f_close, FIL

Return