Initializing Your Region Using the NETMASTR Program › NETMASTR Commands › DD Command—Allocate a Data Set Dynamically

DD Command—Allocate a Data Set Dynamically

The DD command allocates a data set dynamically.

This command has the following format:

DD=name | DD=*
[ ,DSN=datasetname ]
[ ,DISP=( { OLD | SHR | MOD | NEW } [ ,ndisp ] [ ,cdisp ] ] ) ]
[ ,VOL=volume ]
[ ,UNIT=unitname ]
[ ,{ CYL=( pri,sec ) | TRK=( pri,sec ) } ]
[ ,BLKSIZE=nnnnn ]

If the operands cannot fit on one line, you can use the plus sign (+) to indicate that the command is continued. For example:

DD=FRED,+
   DSN=FRED.DATASET,+
   DISP=OLD

DD=name | DD=*

Specifies the ddname being allocated. This operand must be first, and a valid ddname must be used. DD=* dynamically concatenates this data set to the previous data set allocation (which must be a data set, not a SYSOUT allocation).

DSN=datasetname

Specifies the data set to be allocated. A PDS member name or GDG relative generation number can be specified in parenthesis after the data set name.

DISP=( { OLD | SHR | MOD | NEW } [ ,ndisp [ ,cdisp ] ] )

Specifies the data set disposition. ndisp and cdisp are the standard UNCATLG, CATLG, DELETE, and KEEP options and default as in standard JCL. If only the first disposition is required, no parentheses are necessary. For example:

DISP=OLD

VOL=volume

Specifies the volume that the data set is (to be) on. For existing data sets, the operand bypasses a catalog search. Generally, also specify the UNIT operand.

UNIT=unitname

Specifies the unit type that the data set is (to be) on. This operand is required for existing data sets if the volume is specified.

CYL=( pri,sec ) | TRK=( pri,sec )

For new data sets, allows specification of a space allocation value.

Note: You cannot allocate a PDS because no directory amount can be specified.

BLKSIZE=nnnnn

Lets you specify a block size. This operand is also useful when concatenating data sets of unlike block size because it sets the DCB BUFLEN value.