In Common Lisp implementations these conditions are usually reported by default in some way. CL-USER > (with-open-file (s "~/foo.lisp") (read s

In Common Lisp implementations these conditions are usually reported by default in some way. CL-USER > (with-open-file (s "~/foo.lisp") (read s)) Error: The file #P"/Users/joswig/foo.lisp" does not exist. 1 (continue) Try opening "~/foo.lisp" again. 2 (abort) Return to top loop level 0. Type :b for backtrace or :c <option number> to proceed. Type :bug-form "<subject>" for a bug report template or :? for other options. A non-interactive program might bring up such a dialog automatically. When one would do actually application specific error handling, this could (depending on how much comfort is wanted) be much more complex, since Common Lisp has more features to handle and repair errors.