NOTE: Only in Tcl 8.6.
Cancels the script being evaluated in the interpreter identified by path. Without the -unwind switch the evaluation stack for the interpreter is unwound until an enclosing catch command is found or there are no further invocations of the interpreter left on the call stack. With the -unwind switch the evaluation stack for the interpreter is unwound without regard to any intervening catch command until there are no further invocations of the interpreter left on the call stack. The -- switch can be used to mark the end of switches; it may be needed if path is an unusual value such as -safe. If result is present, it will be used as the error message string; otherwise, a default error message string will be used.