dired-after-readin-hook

dired-after-readin-hook is a variable defined in `dired.el'.
Its value is

(dired-omit-expunge)

Original value was

• This variable may be risky if used as a file-local variable.

Documentation:
Hook run after each time a file or directory is read by Dired.
After each listing of a file or directory, this hook is run
with the buffer narrowed to the listing.

You can customize this variable.