How can I get function names defined in Lisp script?

If you want to know, which functions are defined in a certain package, you cane use with-package-iterator macro. Like this: (with-package-iterator (next (find-package 'test) :internal) (loop :for (more? sym) := (multiple-value-list (next)) :if (fboundp sym) :collect sym :into rez :else :unless more? :do (return rez))) If you want to just extract functions from a script(-file), the easiest way seems to be scanning it with a regex "\\(defun (.+)\\s" or something similar.

In very simple cases, you can use regular expressions. In slightly less simple cases, implementing an S-expression reader might be a reasonable approach (you might even get away with ignoring reader macros altogether). In the general case, though, especially if macrology is involved, consider embedding http://common-lisp.net/project/armedbear/, which is a Java implementation of Common Lisp, and using the with-package-iterator form Vsevolod mentioned.