Tcl_SetAssocData(3) Tcl Library Procedures Tcl_SetAssocData(3)
Tcl_GetAssocData, Tcl_SetAssocData, Tcl_DeleteAssocData - manage associations of string
keys and user specified data with Tcl interpreters
Tcl_GetAssocData(interp, key, delProcPtr)
Tcl_SetAssocData(interp, key, delProc, clientData)
Tcl_Interp *interp (in) Interpreter in which to execute the speci-
const char *key (in) Key for association with which to store
data or from which to delete or retrieve
data. Typically the module prefix for a
Tcl_InterpDeleteProc *delProc (in) Procedure to call when interp is deleted.
Tcl_InterpDeleteProc **delProcPtr (in) Pointer to location in which to store
address of current deletion procedure for
association. Ignored if NULL.
ClientData clientData (in) Arbitrary one-word value associated with
the given key in this interpreter. This
data is owned by the caller.
These procedures allow extensions to associate their own data with a Tcl interpreter. An
association consists of a string key, typically the name of the extension, and a one-word
value, which is typically a pointer to a data structure holding data specific to the
extension. Tcl makes no interpretation of either the key or the value for an association.
Storage management is facilitated by storing with each association a procedure to call
when the interpreter is deleted. This procedure can dispose of the storage occupied by the
client's data in any way it sees fit.
Tcl_SetAssocData creates an association between a string key and a user specified datum in
the given interpreter. If there is already an association with the given key, Tcl_SetAs-
socData overwrites it with the new information. It is up to callers to organize their use
of names to avoid conflicts, for example, by using package names as the keys. If the
deleteProc argument is non-NULL it specifies the address of a procedure to invoke if the
interpreter is deleted before the association is deleted. DeleteProc should have argu-
ments and result that match the type Tcl_InterpDeleteProc:
typedef void Tcl_InterpDeleteProc(
When deleteProc is invoked the clientData and interp arguments will be the same as the
corresponding arguments passed to Tcl_SetAssocData. The deletion procedure will not be
invoked if the association is deleted before the interpreter is deleted.
Tcl_GetAssocData returns the datum stored in the association with the specified key in the
given interpreter, and if the delProcPtr field is non-NULL, the address indicated by it
gets the address of the delete procedure stored with this association. If no association
with the specified key exists in the given interpreter Tcl_GetAssocData returns NULL.
Tcl_DeleteAssocData deletes an association with a specified key in the given interpreter.
Then it calls the deletion procedure.
association, data, deletion procedure, interpreter, key
Tcl 7.5 Tcl_SetAssocData(3)