tcl_saveresult(3)
NAME
Tcl_SaveResult, Tcl_RestoreResult, Tcl_DiscardResult save and restore an interpreter's result
SYNOPSIS
#include <tcl.h> Tcl_SaveResult(interp, statePtr) Tcl_RestoreResult(interp, statePtr) Tcl_DiscardResult(statePtr)
ARGUMENTS
- Tcl_Interp *interp (in) Interpreter for
- which state should
be saved. - Tcl_SavedResult *statePtr (in) Pointer to location
- where interpreter
result should be
saved or restored.
DESCRIPTION
These routines allows a C procedure to take a snapshot of
the current interpreter result so that it can be restored
after a call to Tcl_Eval or some other routine that modi
fies the interpreter result. These routines are passed a
pointer to a structure that is used to store enough infor
mation to restore the interpreter result state. This
structure can be allocated on the stack of the calling
procedure. These routines do not save the state of any
error information in the interpreter (e.g. the errorCode
or errorInfo variables).
Tcl_SaveResult moves the string and object results of
interp into the location specified by statePtr.
Tcl_SaveResult clears the result for interp and leaves the
result in its normal empty initialized state.
Tcl_RestoreResult moves the string and object results from
statePtr back into interp. Any result or error that was
already in the interpreter will be cleared. The statePtr
is left in an uninitialized state and cannot be used until
another call to Tcl_SaveResult.
Tcl_DiscardResult releases the saved interpreter state
stored at statePtr. The state structure is left in an
uninitialized state and cannot be used until another call
to Tcl_SaveResult.
Once Tcl_SaveResult is called to save the interpreter
result, either Tcl_RestoreResult or Tcl_DiscardResult must
be called to properly clean up the memory associated with
the saved state.
KEYWORDS
- result, state, interp