Distributed Name Service (DNS) Management Programming Manual

GETVERSION Command
Using DNS in Programs: The DNS Commands
46958 Tandem Computers Incorporated 5–109
Operational Notes
The purpose of ZDNS-CMD-GETVERSION is to allow the management application to
identify the version of DNS that is currently running. Normally, this is the first
command the requester issues to the name manager.
The name manager responds to the command with the following:
ZSPI-TKN-SVRVERSION (header token)
This is the version of the SSPIDEFS for DNS that is current when the name
manager was compiled.
ZSPI-TKN-RETCODE = 0
Requesters that are at a later version than the name manager must exercise care to
ensure that they do not do any of the following:
Request unsupported operations. If a command is issued to the name manager
that the name manager doesn’t support, the command is rejected with ZSPI-TKN-
RETCODE = ZDNS-ERR-CMD-ERR.
Supply values to fields that are not defined in the manager’s version of structured
tokens. All fields that are not supported in the manager’s version of tokens should
be left null.
Supply parameters that are not valid at the manager’s version. If a request
contains a parameter that the manager does not believe is valid for the specified
command, the command is rejected with ZDNS-ERR-ILL-PARAM.
Supply field values that are not legal at the manager’s version.
Where the requester’s version is earlier than the name manager’s version, the name
manager does the following:
Does not return response tokens that were not defined at the requester’s version.
Supplies null values in structured token fields that were not defined at the
requester’s version.
Rejects all commands that were not defined at the requester’s version.
Returns errors where fields are supplied with values that were not valid at the
requester’s version.
DNS does not define new required fields in parameter structured tokens. All new
fields are optional and have a default value.
Requesters should be prepared for additional defined values of enumerated fields and
tokens such as those of type ZDNS-DDL-TYPE. Any variety of CASE statement that
uses the contents of such a field should provide an OTHERWISE escape (or
equivalent) to handle new field or token values.
Additional considerations for requester-server compatibility are discussed under the
INFO NAME command.