@c This is part of the Emacs manual.
@c Copyright (C) 2004--2022 Free Software Foundation, Inc.
@c See file emacs.texi for copying conditions.
@c
@c This file is included either in emacs-xtra.texi (when producing the
@c printed version) or in the main Emacs manual (for the on-line version).
@node Subdir Switches
@section Subdirectory Switches in Dired

You can insert subdirectories with specified @command{ls} switches in
Dired buffers using @kbd{C-u i}.  You can change the @command{ls}
switches of an already inserted subdirectory at point using @kbd{C-u l}.

Dired preserves the switches if you revert the buffer.  Deleting a
subdirectory forgets about its switches.

Using @code{dired-undo}
@iftex
(@pxref{Marks vs Flags,,, emacs, the Emacs Manual})
@end iftex
@ifnottex
(@pxref{Marks vs Flags})
@end ifnottex
to reinsert or delete
subdirectories that were inserted with explicit switches can bypass
Dired's machinery for remembering (or forgetting) switches.  Deleting
a subdirectory using @code{dired-undo} does not forget its switches.
When later reinserted using @kbd{i}, it will be reinserted using its
old switches.  Using @code{dired-undo} to reinsert a subdirectory that
was deleted using the regular Dired commands (not @code{dired-undo})
will originally insert it with its old switches.  Reverting the
buffer, however, will relist it using the buffer's default switches.
If any of this yields problems, you can easily correct the situation
using @kbd{C-u i} or @kbd{C-u l}.

Dired does not remember the @code{R} switch.  Inserting a subdirectory
with switches that include the @code{R} switch is equivalent to
inserting each of its subdirectories using all remaining switches.
For instance, updating or killing a subdirectory that was inserted
with the @code{R} switch will not update or kill its subdirectories.

The buffer's default switches do not affect subdirectories that were
inserted using explicitly specified switches.  In particular,
commands such as @kbd{s} that change the buffer's switches do not
affect such subdirectories.  (They do, however, affect subdirectories
without explicitly assigned switches.)

You can make Dired forget about all subdirectory switches and relist
all subdirectories with the buffer's default switches using
@kbd{M-x dired-reset-subdir-switches}.  This also reverts the Dired buffer.
