error management

[Angelo2449]

Hello everyone,
during code execution, a file is always open waiting for record entries.
I would like to manage any error so that at its occurrence, the file is closed.
Thank you.

 

[x11start]

I use:

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
; error handler ( error management)
; --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
(defun b_err (st)
(setq *error* olderr) ; restore old *error* handler

;;; insert here other system variables or commands to run before the exit

(princ) ; comes out without nil
)