Tcl_SetAssocData(3)         Tcl Library Procedures         Tcl_SetAssocData(3)


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

       #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.    Typi-
                                                      cally  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 pro-
                                                      cedure for  association.
                                                      Ignored if NULL.

       ClientData             clientData    (in)      Arbitrary one-word value
                                                      associated   with    the
                                                      given key in this inter-
                                                      preter.   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 asso-

       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 asso-
       ciation 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  pro-
       cedure  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.  Then it calls the deletion procedure.

       association, data, deletion procedure, interpreter, key

Tcl                                   7.5                  Tcl_SetAssocData(3)