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








#include <tcl.h>

ClientData
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 command.

  
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 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 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_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 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







  

    7.5
    Tcl