Change the fileref for a file as often as you want. ' external-file ' is the physical name of an external file. The physical name is the name that is recognized by the operating environment. For details on specifying the physical names of external files, see the SAS documentation for your operating environment. DISK specifies that the device is a disk drive. PIPE specifies an unnamed pipe.
TAPE specifies a tape drive.
TEMP creates a temporary file that exists only as long as the filename is assigned. The temporary file can be accessed only through the logical name and is available only while the logical name exists. If you do, SAS returns an error. Files manipulated by the TEMP device can have the same attributes and behave identically to DISK files. Values in addition to the ones listed here may be available in some operating environments.