CHANGE-INPUT-TAPEPOSITION

This statement is only permissible in conjunction with tape editing. It is used to position the input tape prior to editing output data. The input tape must have been assigned using the ASSIGN-INPUT-TAPE statement.

The CHANGE-INPUT-TAPEPOSITION statement can be specified only following the ASSIGN-INPUT-TAPE statement, but it can precede or follow the ASSIGN-OUTPUT-FILE statement.

CHANGE-INPUT-TAPEPOSITION

DIRECTION = *BACKWARD (...) / *FORWARD(...)
	*BACKWARD (...)
		|	DESTINATION = *BEGIN-OF-TAPE / *DOUBLE-TAPE-MARK / *BLOCKS(...) / *TAPE-MARKS(...)
		|		*BLOCKS(...)
		|			|	BLOCKS = <integer 1..2147483647>
		|		*TAPE-MARKS(...)
		|			|	TAPE-MARKS = <integer 1..2147483647>
	*FORWARD(...)
		|	DESTINATION = *DOUBLE-TAPE-MARK / *PAST-END-OF-TAPE / *END-OF-TAPE / *BLOCKS(...) / *TAPE-MARKS(...)
		|		*BLOCKS(...)
		|			|	BLOCKS = <integer 1..2147483647>
		|		*TAPE-MARKS(...)
		|			|	TAPE-MARKS = <integer 1..2147483647>

DIRECTION =
Specifies the direction in which the tape is to be positioned.

DIRECTION = *BACKWARD(...)
The input tape is to be positioned backward, i.e. towards the beginning of the tape.

DESTINATION =
Specifies the desired position of the tape.

DESTINATION = *BEGIN-OF-TAPE
The tape is positioned to the beginning of the tape.

DESTINATION = *DOUBLE-TAPE-MARK
The tape is positioned to the next double tape mark.

DESTINATION = *BLOCKS(...)

BLOCKS = <integer 1..2147483647>

Specifies the number of blocks by which the tape is to be repositioned.

DESTINATION = *TAPE-MARKS(...)

TAPE-MARKS = <integer 1..2147483647>

Number of tape marks by which the tape is to be repositioned.

When reading blocks after positioning the tape backward (i.e. towards the beginning of the tape), it is not always possible to determine the current block count correctly. If this occurs, the tape is positioned backward starting at 0.999.999.999.

DIRECTION = *FORWARD(...)
The tape is positioned forwards, i.e. towards the end of the tape.

DESTINATION =
Specifies the desired position of the tape.

DESTINATION = *DOUBLE-TAPE-MARK
The tape is positioned to the next double tape mark.

DESTINATION = *PAST-END-OF-TAPE
Use of this operand is restricted to the system administrator.
The tape is positioned behind the logical end-of-tape. If there is no double tape mark on the tape, the tape is spooled out. This operand cannot be used for tape cartridges.

DESTINATION = *END-OF-TAPE
The tape is positioned to the logical end-of-tape.

DESTINATION = *BLOCKS(...)

BLOCKS = <integer 1..2147483647>

Specifies the number of blocks by which the tape is to be positioned towards the end of the tape.

DESTINATION = *TAPE-MARKS(...)

TAPE-MARKS = <integer 1..2147483647>

Specifies the number of tape marks by which the tape is to be positioned towards the end of the tape.