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The DDE client interface allows Prolog to talk to DDE server programs.
We will demonstrate the use of the DDE interface using the Windows
PROGMAN (Program Manager) application:
1 ?- open_dde_conversation(progman, progman, C).
C = 0
2 ?- dde_request(0, groups, X)
--> Unifies X with description of groups
3 ?- dde_execute(0, '[CreateGroup("DDE Demo")]').
Yes
4 ?- close_dde_conversation(0).
Yes
For details on interacting with PROGMAN, use the SDK online manual
section on the Shell DDE interface. See also the Prolog library
progman.pl, which may be used to write simple Windows setup scripts in
Prolog.
- open_dde_conversation( +Service, +Topic, -Handle)
Open a conversation with a server supporting the given service name and
topic (atoms). If successful, Handle may be used to send
transactions to the server. If no willing server is found this
predicate fails silently.
- close_dde_conversation( +Handle)
Close the conversation associated with Handle. All opened
conversations should be closed when they're no longer needed, although
the system will close any that remain open on process termination.
- dde_request( +Handle, +Item, -Value)
Request a value from the server. Item is an atom that identifies
the requested data, and Value will be an atom ( CF_TEXT data
in DDE parlance) representing that data, if the request is successful.
If unsuccessful, Value will be unified with a term of form
error(reason), identifying the problem.
It could be argued that the atoms above should be strings.
- dde_execute( +Handle, +Command)
Request the DDE server to execute the given command-string. Succeeds
if the command could be executed and fails with error message otherwise.
Passani Luca
Tue Nov 14 08:58:33 MET 1995