Ep586, Emacs Lisp, Rename All Link of HTML Files

notes at
xahlee.info/tal...
note, there is an error.
in the function directory-files-recursively, to skip dir name starting with a dot,
the proper predicate is
(lambda (x) (not (string-match-p "/\\." x)))
because the function is passed a subdirectory full path, not just name.