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:

(directory-files "/some/dir/name"
                 nil        ;; just the filenames, not full paths
                 "\\.c\\'"  ;; regexp
                 t)         ;; don't sort the filenames
;;=> ("foo.c" "bar.c" ...)