The get_uid_gid_supgrps service gets the real, effective, and saved z/OS UNIX user identifiers (UIDs) and z/OS UNIX group identifiers (GIDs), and the supplemental groups from the USP.

Because the size of the supplemental group list varies, IRRSGE00 checks the input group count before putting supplemental GIDs in the grouplist area. See Group_count under Parameters for more information.

The GIDs are not explicitly added to or deleted from the supplemental group list. A GID is in this list if the user was a member of the group when the user's ACEE was created through a RACROUTE REQUEST=VERIFY request and if the GID was assigned to the group before the initUSP service was performed for the process.