Group data area

The system creates a group data area when an interactive job becomes a group job (using the Change Group Attributes (CHGGRPA) command).

Only one group data area can exist for a group. The group data area is deleted when the last job in the group is ended (with the ENDJOB, SIGNOFF, or ENDGRPJOB command, or with an abnormal end), or when the job is no longer part of the group job (using the CHGGRPA command with GRPJOB(*NONE) specified).

A group data area, which is initially filled with blanks, has a length of 512 and type *CHAR. You can use a group data area from within a group job by specifying *GDA for the DTAARA parameter on the CHGDTAARA, RTVDTAARA, and DSPDTAARA commands. A group data area is accessible to all of the jobs in the group.

The following are true for a group data area:

• You cannot use the group data area as a substitute for a character variable on the substring built-in function (%SUBSTRING or %SST). (You can, however, move a 512-byte character variable used by the substring function into or out of the group data area.)
• A group data area cannot be referred to by jobs outside the group.
• You cannot create, delete, or allocate a group data area.
• No library is associated with a group data area.

The contents of a group data area are unchanged by the Transfer to Group Job (TFRGRPJOB) command.

In addition to using the group data area as you use other data areas, you can use the group data area to communicate information between group jobs in the same group. For example, after issuing the Change Group Job Attributes (CHGGRPA) command, the following command can be used to set the value of the group data area:

CHGDTAARA  DTAARA(*GDA)  VALUE('January1988')

This command can be run from a program or can be issued by the workstation user.

Any other CL procedure or program in the group can retrieve the value of the group data area with the following CL command:

RTVDTAARA  DTAARA(*GDA)  RTNVAR(&GRPARA)

This command places the value of the group data area (January1988) into CL variable &GRPARA.