Groups and Group Identifiers

Applications can maintain information about many independent groups simultaneously. The maximum number of simultaneously active groups is currently set to 500 and is given by the symbolic constant GRP__MAXG. There is no limit on the number of names that a single group can contain (other than those imposed by system quotas).

The GRP system distinguishes between different groups by use of an identifier system. When a new group is created, it is assigned a ``GRP identifier'' or ``group identifier''. This value is used to specify which group is to be acted upon by subsequent GRP calls. The symbolic constant GRP__NOID can be given in certain places where a GRP identifier would normally be given, in order to specify a ``null'' group. Note, identifiers in the GRP package cannot be ``cloned'' to produce alternative, independent channels for accessing the same group. If two integer variables contain identifiers for a single group, then the integer values stored in the two variables will always be equal.