Emacs/docs/latest/emacs/Flagging-Many-Files

30.4 Flagging Many Files at Once

The #, ~, ., % &, and % d commands flag many files for deletion, based on their file names:

#: Flag all auto-save files (files whose names start and end with ‘#’) for deletion (see Auto Save).
~: Flag all backup files (files whose names end with ‘~’) for deletion (see Backup).
. (Period): Flag excess numeric backup files for deletion. The oldest and newest few backup files of any one file are exempt; the middle ones are flagged.
% &: Flag for deletion all files with certain kinds of names which suggest you could easily create those files again.
% d regexp RET: Flag for deletion all files whose names match the regular expression regexp.

# (dired-flag-auto-save-files) flags all files whose names look like auto-save files—that is, files whose names begin and end with ‘#’. See Auto Save.

~ (dired-flag-backup-files) flags all files whose names say they are backup files—that is, files whose names end in ‘~’. See Backup.

. (period, dired-clean-directory) flags just some of the backup files for deletion: all but the oldest few and newest few backups of any one file. Normally, the number of newest versions kept for each file is given by the variable dired-kept-versions (not kept-new-versions; that applies only when saving). The number of oldest versions to keep is given by the variable kept-old-versions.

Period with a positive numeric argument, as in C-u 3 ., specifies the number of newest versions to keep, overriding dired-kept-versions. A negative numeric argument overrides kept-old-versions, using minus the value of the argument to specify the number of oldest versions of each file to keep.

% & (dired-flag-garbage-files) flags files whose names match the regular expression specified by the variable dired-garbage-files-regexp. By default, this matches certain files produced by TeX, ‘.bak’ files, and the ‘.orig’ and ‘.rej’ files produced by patch.

% d flags all files whose names match a specified regular expression (dired-flag-files-regexp). Only the non-directory part of the file name is used in matching. You can use ‘^’ and ‘$’ to anchor matches. You can exclude certain subdirectories from marking by hiding them while you use % d. See Hiding Subdirectories.