Tcl_CreateCloseHandler, Tcl_DeleteCloseHandler - arrange for callbacks when channels are closed

       Tcl_Channel channel (in)               The channel for which to create or delete a close callback.

       Tcl_CloseProc *proc (in)               The procedure to call as the callback.

       void *clientData (in)                  Arbitrary one-word value to pass to proc.
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Tcl_CreateCloseHandler  arranges  for  proc  to  be  called  when  channel  is  closed  with Tcl_Close or
       Tcl_UnregisterChannel, or using the Tcl close command.  Proc should match the following prototype:

              typedef void Tcl_CloseProc(
                      void *clientData);

       The clientData is the same as the value provided in the call to Tcl_CreateCloseHandler.

       Tcl_DeleteCloseHandler removes a close callback for channel.  The  proc  and  clientData  identify  which
       close callback to remove; Tcl_DeleteCloseHandler does nothing if its proc and clientData arguments do not
       match the proc and clientData for a  close handler for channel.

       callback, channel closing

Tcl                                                    7.5                          Tcl_CreateCloseHandler(3tcl)

       Tcl_CreateCloseHandler, Tcl_DeleteCloseHandler - arrange for callbacks when channels are closed

close(3tcl), Tcl_Close(3tcl), Tcl_UnregisterChannel(3tcl)

#include<tcl.h>Tcl_CreateCloseHandler(channel,proc,clientData)

       Tcl_DeleteCloseHandler(channel,proc,clientData)