Problem Statement

Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)

Note: This task is for non-recursive methods.   These tasks should read a single directory, not an entire directory tree.
Note: Please be careful when running any code presented here.

Let's start with the solution:

(defun walk-directory (directory pattern)
  (directory (merge-pathnames pattern directory)))