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Tcl_SetAssocData(3tcl) Tcl Library Procedures Tcl_SetAssocData(3tcl)
 


NAME

Tcl_GetAssocData, Tcl_SetAssocData, Tcl_DeleteAssocData - manage associations of
  string keys and user specified data with Tcl interpreters

SYNOPSIS


#include <tcl.h>


ClientData
Tcl_GetAssocData(interp, key, delProcPtr)


Tcl_SetAssocData(interp, key, delProc, clientData)


Tcl_DeleteAssocData(interp, key)



ARGUMENTS



  
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.
    
    

    
 

    

  




DESCRIPTION

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.

KEYWORDS

association, data, deletion procedure, interpreter, key



  

    7.5
    Tcl