SetTapePosition
The SetTapePosition
sets the tape position on the specified device.
DWORD SetTapePosition(
|
HANDLE hDevice, |
// handle of open
device |
|
DWORD dwPositionMethod, |
// type of
positioning to perform |
|
DWORD dwPartition, |
// new tape
partition |
|
DWORD dwOffsetLow, |
// low-order 32
bits of tape position |
|
DWORD dwOffsetHigh, |
// high-order 32
bits of tape position |
|
BOOL bImmediate |
// return after
operation begins |
|
); |
|
Parameters
hDevice
Identifies
the device on which to set the tape position. This handle is created by using
the CreateFile
function.
dwPositionMethod
Specifies the
type of positioning to perform. This parameter must be one of the following
values:
|
Value |
Meaning |
|
TAPE_ABSOLUTE_BLOCK |
Moves the
tape to the device-specific block address specified by the dwOffsetLow
and dwOffsetHigh parameters. The dwPartition parameter is
ignored. |
|
TAPE_LOGICAL_BLOCK |
Moves the
tape to the block address specified by dwOffsetLow and dwOffsetHigh
in the partition specified by dwPartition. |
|
TAPE_REWIND |
Moves the
tape to the beginning of the current partition. The dwPartition, dwOffsetLow,
and dwOffsetHigh parameters are ignored. |
|
TAPE_SPACE_END_OF_DATA |
Moves the
tape to the end of the data on the partition specified by dwPartition. |
|
TAPE_SPACE_FILEMARKS |
Moves the
tape forward (or backward) the number of filemarks specified by dwOffsetLow
and dwOffsetHigh in the current partition. The dwPartition
parameter is ignored. |
|
TAPE_SPACE_RELATIVE_BLOCKS |
Moves the
tape forward (or backward) the number of blocks specified by dwOffsetLow
and dwOffsetHigh in the current partition. The dwPartition
parameter is ignored. |
|
TAPE_SPACE_SEQUENTIAL_FMKS |
Moves the
tape forward (or backward) to the first occurrence of n filemarks in
the current partition, where n is the number specified by dwOffsetLow
and dwOffsetHigh. The dwPartition parameter is ignored. |
|
TAPE_SPACE_SEQUENTIAL_SMKS |
Moves the
tape forward (or backward) to the first occurrence of n setmarks in
the current partition, where n is the number specified by dwOffsetLow
and dwOffsetHigh. The dwPartition parameter is ignored. |
|
TAPE_SPACE_SETMARKS |
Moves the
tape forward (or backward) the number of setmarks specified by dwOffsetLow
and dwOffsetHigh in the current partition. The dwPartition
parameter is ignored. |
dwPartition
Specifies the
partition to position within. If dwPartition is zero, the current
partition is used. Partitions are numbered logically from 1 through n,
where 1 is the first partition on the tape and n is the last.
dwOffsetLow
Specifies the
low-order 32 bits of the block address or count for the position operation
specified by the dwPositionMethod parameter.
dwOffsetHigh
Specifies the
high-order 32 bits of the block address or count for the position operation
specified by the dwPositionMethod parameter. If the high-order 32 bits
are not required, this parameter should be zero.
bImmediate
Indicates
whether to return as soon as the move operation begins. If this parameter is
TRUE, the function returns immediately; if FALSE, the function does not return
until the move operation has been completed.
Return Values
If the
function succeeds, the return value is NO_ERROR.
If the function
fails, the return value is one of the following error codes:
|
Error |
Description |
|
ERROR_BEGINNING_OF_MEDIA |
An attempt
to access data before the beginning-of-medium marker failed. |
|
ERROR_BUS_RESET |
A reset
condition was detected on the bus. |
|
ERROR_END_OF_MEDIA |
The
end-of-tape marker was reached during an operation. |
|
ERROR_FILEMARK_DETECTED |
A filemark
was reached during an operation. |
|
ERROR_SETMARK_DETECTED |
A setmark
was reached during an operation. |
|
ERROR_NO_DATA_DETECTED |
The
end-of-data marker was reached during an operation. |
|
ERROR_PARTITION_FAILURE |
The tape
could not be partitioned. |
|
ERROR_INVALID_BLOCK_LENGTH |
The block
size is incorrect on a new tape in a multivolume partition. |
|
ERROR_DEVICE_NOT_PARTITIONED |
The
partition information could not be found when a tape was being loaded. |
|
ERROR_MEDIA_CHANGED |
The tape
that was in the drive has been replaced or removed. |
|
ERROR_NO_MEDIA_IN_DRIVE |
There is no
media in the drive. |
|
ERROR_NOT_SUPPORTED |
The tape
driver does not support a requested function. |
|
ERROR_UNABLE_TO_LOCK_MEDIA |
An attempt
to lock the ejection mechanism failed. |
|
ERROR_UNABLE_TO_UNLOAD_MEDIA |
An attempt
to unload the tape failed. |
|
ERROR_WRITE_PROTECT |
The media
is write protected. |
Remarks
If the offset
specified by dwOffsetLow and dwOffsetHigh specifies the number of
blocks, filemarks, or setmarks to move, a positive offset moves the tape
forward to the end of the last block, filemark, or setmark. A negative offset
moves the tape backward to the beginning of the last block, filemark, or
setmark. If the offset is zero, the tape does not move.
To obtain
information about the status, capabilities, and capacities of tape drives and
media, call the GetTapeParameters function.
See Also