Tcl_SetAssocData(3) Tcl Library Procedures Tcl_SetAssocData(3)______________________________________________________________________________NAME
Tcl_GetAssocData, Tcl_SetAssocData, Tcl_DeleteAssocData - manage asso‐
ciations 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 associa‐
tion. 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 asso‐
ciation.
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 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
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
Tcl 7.5 Tcl_SetAssocData(3)
