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

       #include <tcl.h>

       Tcl_GetAssocData(interp, key, delProcPtr)

       Tcl_SetAssocData(interp, key, delProc, clientData)

       Tcl_DeleteAssocData(interp, key)

       Tcl_Interp             *interp       (in)      Interpreter in which to
                                                      execute the specified

       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 package.

       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

       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

       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

       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_SetAssocData 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 arguments and result
       that match the type Tcl_InterpDeleteProc:
              typedef void Tcl_InterpDeleteProc(
                ClientData clientData,
                Tcl_Interp *interp);
       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

       Tcl_DeleteAssocData deletes an association with a specified key in the
       given interpreter.  It does not call the deletion procedure.

       association, data, deletion procedure, interpreter, key

Tcl                                   7.5                  Tcl_SetAssocData(3)