The TAPRD procedure reads the next record on the selected tape unit into the specified array. TAPRD is available only under VMS. No data or format conversion, with the exception of optional byte reversal, is performed. The array must be defined with the desired type and dimensions. If the read is successful, the system variable !ERR is set to the number of bytes read. See the description of the magnetic tape routines in VMS-Specific Information .

Calling Sequence

TAPRD, Array, Unit [, Byte_Reverse]



The magnetic tape unit to read. This argument must be a number between 0 and 9, and should not be confused with standard file Logical Unit Numbers (LUN's).


A named variable into which the data is read. If Array is larger than the tape record, the extra elements of the array are not changed. If the array is shorter than the tape record, a data overrun error occurs. The length of Array and the records on the tape can range from 14 bytes to 65,235 bytes.


If this parameter is present, the even and odd numbered bytes are swapped after reading, regardless of the type of data or variables. This enables reading tapes containing short integers that were written on machines with different byte ordering. You can also use the BYTORDER routine to re-order different data types.

See Also