Obtain an identifier for an existing catalogue via the parameter system LPG_CATASSOC
On the first invocation of the application, a group of names of existing catalogues will be obtained from the environment using the specified parameter, and a CAT identifier for the first one will be returned. If more than one catalogue was supplied for the parameter then the application may be invoked again (see LPG_AGAIN), in which case this routine will return an identifier for the next catalogue in the group supplied on the first invocation.
If an application attempts to get a new catalogue by cancelling the parameter (PAR_CANCL), the
returned catalogue is NOT the next one in the group, but is obtained by prompting the user for a single
catalogue.
The monolith routine should arrange to invoke the application repeatedly until one or more of its catalogue parameters have been exhausted (i.e. all its values used). See LPG_AGAIN.
’READ’, or ’WRITE’.