ediff-merge-directories

ediff-merge-directories is an interactive autoloaded compiled Lisp function in `ediff.el'.

It is bound to <menu-bar> <tools> <ediff-merge> <ediff-merge-directories>.

(ediff-merge-directories DIR1 DIR2 REGEXP &optional MERGE-AUTOSTORE-DIR)

Run Ediff on a pair of directories, DIR1 and DIR2, merging files that have
the same name in both. The third argument, REGEXP, is nil or a regular
expression; only file names that match the regexp are considered.