Tcl extensions
Tcl extensions enable message manipulation within the engine.
For additional information, numerous web sites are devoted to Tcl, including the Tcl Developer Xchange. See www.tcl.tk.
Conventions
Command lines often contain special characters:
?
(optional)|
(or)...
(and so on)-
(options)- variable (required variable)
Engine information
The engprotostate command is only valid in a Tcl interpreter within a protocol thread. It returns the protocol state of the current thread as a readable string (initializing, opening, up, down, closing, error, or ineof).