How Does this Code Work: Error Handling

Hi,

(defun c:90elbow (/ inspoint px py part1 part2 *Error*)
(setq *Error* Error)
;My really long code;
)

(defun Error (Msg)
(cond
((member (strcase Msg T) '("console break" "function cancelled" "quit /
exit abort")))
((princ (strcat "\nERROR: " Msg))))
(princ)
)

I was wondering, if there is somebody that would be kind enough to explain
to me how this error code works? Specifically I am at a loss to describe
the origins of Msg, as the 3 instances of it above are the only ones in my
code. I also can not figure out how *Error* is related to the Error
function?

Thank you

 

*Error* - is the "command" cad calls up when there is a problem.. so by
changing were it is directed (the setq *error* bit) you are telling cad
to call up your error lisp when there is a problem

msg - is the message that cad supplies (the description of what
happened). it's not somthing you want to set.

HTH

 

Cool, thank you for clearing that up for me.

 

Jim,

That process was relevant for R14 and earlier, but unneeded in A2k and
above. Localizing *error* before redefining it is all you need to do now.

--
R. Robert Bell


Check-out the attached LSP file. It contains a command that show the proper
use of the *error* function and most importantly how to set it back. You
most likely don't want to "permanently" change this function, although I see
you have localized the *error* function.