diff --git a/doc/lispref/files.texi b/doc/lispref/files.texi
index 3b8b4fb3a9..2f15176e79 100644
--- a/doc/lispref/files.texi
+++ b/doc/lispref/files.texi
@@ -2917,7 +2917,7 @@ Contents of Directories
the latter case, it can optionally display information about each file,
depending on the options passed to the @code{ls} command.
-@defun directory-files directory &optional full-name match-regexp nosort
+@defun directory-files directory &optional full-name match-regexp nosort count
This function returns a list of the names of the files in the directory
@var{directory}. By default, the list is in alphabetical order.
@@ -2937,6 +2937,13 @@ Contents of Directories
are processed in. If the order of processing is visible to the user,
then the user will probably be happier if you do sort the names.
+If @var{count} is non-@code{nil}, the function will return first
+@var{count} number of files, or all files, whichever occurs
+first. @var{count} has to be a natural number (> 0). You can use this
+function to short circuit evaluation in case you are just interested to
+find if a directory is empty or not (request one file and tell it to
+ignore dot-files).
+
@example
@group
(directory-files "~lewis")
@@ -2946,6 +2953,14 @@ Contents of Directories
@end group
@end example
+@example
+@group
+ (null (directory-files directory-name nil
+ "^\\([^.]\\|\\.\\([^.]\\|\\..\\)\\).*" t 1))
+ @result{} nil
+@end group
+@end example
+
An error is signaled if @var{directory} is not the name of a directory
that can be read.
@end defun
@@ -2996,7 +3011,7 @@ Contents of Directories
non-@code{nil} if that directory is the one it is looking for.
@end defun
-@defun directory-files-and-attributes directory &optional full-name match-regexp nosort id-format
+@defun directory-files-and-attributes directory &optional full-name match-regexp nosort id-format count
This is similar to @code{directory-files} in deciding which files
to report on and how to report their names. However, instead
of returning a list of file names, it returns for each file a
diff --git a/etc/NEWS b/etc/NEWS
index 1838b6b38a..25c54d3dfe 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1550,6 +1550,13 @@ ledit.el, lmenu.el, lucid.el and old-whitespace.el.
* Lisp Changes in Emacs 28.1
++++
+** 'diirectory-files' function can now take an additional count parameter
+This option makes directory-files return COUNT first files in
+directory. If match is given, the function vill return first COUNT files
+that match the expression. The option is useful for checking if
+directory is empty since it will check at most 3 files when COUNT = 1.
+
+++
** 'truncate-string-ellipsis' now uses '…' by default.
Modes that use 'truncate-string-to-width' with non-nil, non-string
diff --git a/lisp/net/ange-ftp.el b/lisp/net/ange-ftp.el
index 0cb8d7cb83..335a07914c 100644
--- a/lisp/net/ange-ftp.el
+++ b/lisp/net/ange-ftp.el
@@ -3427,8 +3427,8 @@ ange-ftp-file-accessible-directory-p
(and (file-directory-p name)
(file-readable-p name)))
-(defun ange-ftp-directory-files (directory &optional full match
- &rest v19-args)
+(defun ange-ftp-directory-files (directory &optional full match nosort
+ count)
(setq directory (expand-file-name directory))
(if (ange-ftp-ftp-name directory)
(progn
@@ -3444,18 +3444,19 @@ ange-ftp-directory-files
(setq files
(cons (if full (concat directory f) f) files))))
(nreverse files)))
- (apply 'ange-ftp-real-directory-files directory full match v19-args)))
+ (apply 'ange-ftp-real-directory-files directory full match nosort count)))
(defun ange-ftp-directory-files-and-attributes
- (directory &optional full match nosort id-format)
+ (directory &optional full match nosort attrs id-format count)
(setq directory (expand-file-name directory))
(if (ange-ftp-ftp-name directory)
(mapcar
(lambda (file)
(cons file (file-attributes (expand-file-name file directory))))
- (ange-ftp-directory-files directory full match nosort))
+ (ange-ftp-directory-files directory full match nosort attrs
+ id_format count))
(ange-ftp-real-directory-files-and-attributes
- directory full match nosort id-format)))
+ directory full match nosort attrs id-format count)))
(defun ange-ftp-file-attributes (file &optional id-format)
(setq file (expand-file-name file))
diff --git a/lisp/net/tramp-adb.el b/lisp/net/tramp-adb.el
index 49ecaa58ee..26ec24a075 100644
--- a/lisp/net/tramp-adb.el
+++ b/lisp/net/tramp-adb.el
@@ -301,7 +301,7 @@ tramp-do-parse-file-attributes-with-ls
file-properties)))
(defun tramp-adb-handle-directory-files-and-attributes
- (directory &optional full match nosort id-format)
+ (directory &optional full match nosort id-format count)
"Like `directory-files-and-attributes' for Tramp files."
(unless (file-exists-p directory)
(tramp-error
@@ -312,7 +312,7 @@ tramp-adb-handle-directory-files-and-attributes
(copy-tree
(with-tramp-file-property
v localname (format "directory-files-and-attributes-%s-%s-%s-%s"
- full match id-format nosort)
+ full match id-format nosort count)
(with-current-buffer (tramp-get-buffer v)
(when (tramp-adb-send-command-and-check
v (format "%s -a -l %s"
diff --git a/lisp/net/tramp-crypt.el b/lisp/net/tramp-crypt.el
index 3e96daa7b1..bda3735db4 100644
--- a/lisp/net/tramp-crypt.el
+++ b/lisp/net/tramp-crypt.el
@@ -667,7 +667,10 @@ tramp-crypt-handle-delete-file
(let (tramp-crypt-enabled)
(delete-file (tramp-crypt-encrypt-file-name filename) trash))))
-(defun tramp-crypt-handle-directory-files (directory &optional full match nosort)
+;; This function does not seem to pass match and nosort into
+;; directory-files at all; is that intentional or bug?
+(defun tramp-crypt-handle-directory-files (directory &optional full
+ match nosort count)
"Like `directory-files' for Tramp files."
(unless (file-exists-p directory)
(tramp-error
diff --git a/lisp/net/tramp-rclone.el b/lisp/net/tramp-rclone.el
index 3701bfc22c..787eead807 100644
--- a/lisp/net/tramp-rclone.el
+++ b/lisp/net/tramp-rclone.el
@@ -300,8 +300,10 @@ tramp-rclone-handle-delete-file
(tramp-flush-file-properties v localname)
(tramp-rclone-flush-directory-cache v)))
+;; This function did not pass nosort arguemnt into directory-files
+;; not sure if intentional or bug
(defun tramp-rclone-handle-directory-files
- (directory &optional full match nosort)
+ (directory &optional full match nosort count)
"Like `directory-files' for Tramp files."
(unless (file-exists-p directory)
(tramp-error
@@ -312,7 +314,8 @@ tramp-rclone-handle-directory-files
(with-parsed-tramp-file-name directory nil
(let ((result
(directory-files
- (tramp-rclone-local-file-name directory) full match)))
+ (tramp-rclone-local-file-name directory) full match
+ nosort count)))
;; Massage the result.
(when full
(let ((local (concat "^" (regexp-quote (tramp-rclone-mount-point v))))
diff --git a/lisp/net/tramp-sh.el b/lisp/net/tramp-sh.el
index 15eab0a4de..7a969979ac 100644
--- a/lisp/net/tramp-sh.el
+++ b/lisp/net/tramp-sh.el
@@ -1701,9 +1701,9 @@ tramp-sh-handle-file-ownership-preserved-p
(tramp-get-remote-gid v 'integer)))))))))
;; Directory listings.
-
+;; what about perl & sta -> need to fix list to count?
(defun tramp-sh-handle-directory-files-and-attributes
- (directory &optional full match nosort id-format)
+ (directory &optional full match nosort id-format count)
"Like `directory-files-and-attributes' for Tramp files."
(unless id-format (setq id-format 'integer))
(unless (file-exists-p directory)
@@ -1743,7 +1743,7 @@ tramp-sh-handle-directory-files-and-attributes
(sort result (lambda (x y) (string< (car x) (car y)))))
;; The scripts could fail, for example with huge file size.
(tramp-handle-directory-files-and-attributes
- directory full match nosort id-format)))))
+ directory full match nosort id-format count)))))
(defun tramp-do-directory-files-and-attributes-with-perl
(vec localname &optional id-format)
diff --git a/lisp/net/tramp-smb.el b/lisp/net/tramp-smb.el
index 1b6af2a2e3..62135f514d 100644
--- a/lisp/net/tramp-smb.el
+++ b/lisp/net/tramp-smb.el
@@ -690,29 +690,36 @@ tramp-smb-handle-delete-file
v 'file-error "%s `%s'" (match-string 0) filename))))))
(defun tramp-smb-handle-directory-files
- (directory &optional full match nosort)
+ (directory &optional full match nosort count)
"Like `directory-files' for Tramp files."
(unless (file-exists-p directory)
(tramp-error
(tramp-dissect-file-name directory) tramp-file-missing
"No such file or directory" directory))
- (let ((result (mapcar #'directory-file-name
- (file-name-all-completions "" directory))))
- ;; Discriminate with regexp.
- (when match
- (setq result
- (delete nil
- (mapcar (lambda (x) (when (string-match-p match x) x))
- result))))
- ;; Prepend directory.
- (when full
- (setq result
- (mapcar
- (lambda (x) (format "%s/%s" (directory-file-name directory) x))
- result)))
- ;; Sort them if necessary.
- (unless nosort (setq result (sort result #'string-lessp)))
- result))
+ (let ((result nil)
+ (numres 0))
+ (when (or (not count) (> count 0))
+ (setq result (mapcar #'directory-file-name
+ (file-name-all-completions "" directory)))
+ ;; Discriminate with regexp.
+ (when match
+ (setq result
+ (delete nil
+ (mapcar (lambda (x) (when (string-match-p match x) x))
+ result))))
+
+ ;; return [0,count) number of results
+ (setq result (cl-subseq result 0 count))
+
+ ;; Prepend directory.
+ (when full
+ (setq result
+ (mapcar
+ (lambda (x) (format "%s/%s" (directory-file-name directory) x))
+ result)))
+ ;; Sort them if necessary.
+ (unless nosort (setq result (sort result #'string-lessp)))
+ result)))
(defun tramp-smb-handle-expand-file-name (name &optional dir)
"Like `expand-file-name' for Tramp files."
diff --git a/lisp/net/tramp.el b/lisp/net/tramp.el
index 6d44ad23ad..a99af70196 100644
--- a/lisp/net/tramp.el
+++ b/lisp/net/tramp.el
@@ -3114,7 +3114,8 @@ tramp-handle-directory-file-name
(setq directory (substring directory 0 -1)))
directory)
-(defun tramp-handle-directory-files (directory &optional full match nosort)
+(defun tramp-handle-directory-files (directory &optional full match
+ nosort count)
"Like `directory-files' for Tramp files."
(unless (file-exists-p directory)
(tramp-error
@@ -3133,13 +3134,13 @@ tramp-handle-directory-files
(if nosort result (sort result #'string<)))))
(defun tramp-handle-directory-files-and-attributes
- (directory &optional full match nosort id-format)
+ (directory &optional full match nosort id-format count)
"Like `directory-files-and-attributes' for Tramp files."
(mapcar
(lambda (x)
(cons x (file-attributes
(if full x (expand-file-name x directory)) id-format)))
- (directory-files directory full match nosort)))
+ (directory-files directory full match nosort count)))
(defun tramp-handle-dired-uncache (dir)
"Like `dired-uncache' for Tramp files."
diff --git a/src/dired.c b/src/dired.c
index 1584b6acf0..1fc8dd27fa 100644
--- a/src/dired.c
+++ b/src/dired.c
@@ -17,7 +17,6 @@
You should have received a copy of the GNU General Public License
along with GNU Emacs. If not, see . */
-
#include
#include
@@ -165,8 +164,26 @@ read_dirent (DIR *dir, Lisp_Object dirname)
Lisp_Object
directory_files_internal (Lisp_Object directory, Lisp_Object full,
Lisp_Object match, Lisp_Object nosort, bool attrs,
- Lisp_Object id_format)
+ Lisp_Object id_format, Lisp_Object return_count)
{
+ ptrdiff_t ind = 0, last = 0;
+
+ /* check count first for early exit */
+ if (FIXNUMP(return_count))
+ {
+ last = XFIXNUM (return_count);
+ if (last <= 0)
+ return Qnil;
+ }
+
+ if (FIXNATP(return_count))
+ {
+ last = XFIXNAT(return_count);
+
+ if (!last)
+ return Qnil;
+ }
+
if (!NILP (match))
CHECK_STRING (match);
@@ -267,6 +284,10 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full,
else
finalname = name;
+ if (last && ind == last)
+ break;
+ ind ++;
+
list = Fcons (attrs ? Fcons (finalname, fileattrs) : finalname, list);
}
@@ -287,8 +308,7 @@ directory_files_internal (Lisp_Object directory, Lisp_Object full,
return list;
}
-
-DEFUN ("directory-files", Fdirectory_files, Sdirectory_files, 1, 4, 0,
+DEFUN ("directory-files", Fdirectory_files, Sdirectory_files, 1, 5, 0,
doc: /* Return a list of names of files in DIRECTORY.
There are three optional arguments:
If FULL is non-nil, return absolute file names. Otherwise return names
@@ -296,9 +316,12 @@ DEFUN ("directory-files", Fdirectory_files, Sdirectory_files, 1, 4, 0,
If MATCH is non-nil, mention only file names that match the regexp MATCH.
If NOSORT is non-nil, the list is not sorted--its order is unpredictable.
Otherwise, the list returned is sorted with `string-lessp'.
- NOSORT is useful if you plan to sort the result yourself. */)
+ NOSORT is useful if you plan to sort the result yourself.
+If COUNT is non-nil, the function will return max of COUNT and length
+ files, where length is number of files in the directory. COUNT has to
+ be a natural number > 0. */)
(Lisp_Object directory, Lisp_Object full, Lisp_Object match,
- Lisp_Object nosort)
+ Lisp_Object nosort, Lisp_Object count)
{
directory = Fexpand_file_name (directory, Qnil);
@@ -306,34 +329,38 @@ DEFUN ("directory-files", Fdirectory_files, Sdirectory_files, 1, 4, 0,
call the corresponding file name handler. */
Lisp_Object handler = Ffind_file_name_handler (directory, Qdirectory_files);
if (!NILP (handler))
- return call5 (handler, Qdirectory_files, directory,
- full, match, nosort);
+ return call6 (handler, Qdirectory_files, directory,
+ full, match, nosort, count);
- return directory_files_internal (directory, full, match, nosort, false, Qnil);
+ return directory_files_internal (directory, full, match, nosort,
+ false, Qnil, count);
}
DEFUN ("directory-files-and-attributes", Fdirectory_files_and_attributes,
- Sdirectory_files_and_attributes, 1, 5, 0,
- doc: /* Return a list of names of files and their attributes in DIRECTORY.
+ Sdirectory_files_and_attributes, 1, 6, 0, doc
+ : /* Return a list of names of files and their attributes in DIRECTORY.
Value is a list of the form:
- ((FILE1 . FILE1-ATTRS) (FILE2 . FILE2-ATTRS) ...)
+((FILE1 . FILE1-ATTRS) (FILE2 . FILE2-ATTRS) ...)
where each FILEn-ATTRS is the attributes of FILEn as returned
by `file-attributes'.
This function accepts four optional arguments:
If FULL is non-nil, return absolute file names. Otherwise return names
- that are relative to the specified directory.
+that are relative to the specified directory.
If MATCH is non-nil, mention only file names that match the regexp MATCH.
If NOSORT is non-nil, the list is not sorted--its order is unpredictable.
- NOSORT is useful if you plan to sort the result yourself.
+NOSORT is useful if you plan to sort the result yourself.
ID-FORMAT specifies the preferred format of attributes uid and gid, see
`file-attributes' for further documentation.
On MS-Windows, performance depends on `w32-get-true-file-attributes',
-which see. */)
- (Lisp_Object directory, Lisp_Object full, Lisp_Object match,
- Lisp_Object nosort, Lisp_Object id_format)
+which see.
+If COUNT is non-nil, the function will return max of COUNT and length
+ files, where length is number of files in the directory. COUNT has to
+ be a natural number > 0. */)
+(Lisp_Object directory, Lisp_Object full, Lisp_Object match,
+ Lisp_Object nosort, Lisp_Object id_format, Lisp_Object count)
{
directory = Fexpand_file_name (directory, Qnil);
@@ -342,11 +369,11 @@ DEFUN ("directory-files-and-attributes", Fdirectory_files_and_attributes,
Lisp_Object handler
= Ffind_file_name_handler (directory, Qdirectory_files_and_attributes);
if (!NILP (handler))
- return call6 (handler, Qdirectory_files_and_attributes,
- directory, full, match, nosort, id_format);
+ return call7 (handler, Qdirectory_files_and_attributes,
+ directory, full, match, nosort, id_format, count);
return directory_files_internal (directory, full, match, nosort,
- true, id_format);
+ true, id_format, count);
}
diff --git a/src/lisp.h b/src/lisp.h
index 45353fbef3..a3cfb5044d 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -4612,7 +4612,7 @@ maybe_disable_address_randomization (int argc, char **argv)
extern void syms_of_dired (void);
extern Lisp_Object directory_files_internal (Lisp_Object, Lisp_Object,
Lisp_Object, Lisp_Object,
- bool, Lisp_Object);
+ bool, Lisp_Object, Lisp_Object);
/* Defined in term.c. */
extern int *char_ins_del_vector;
diff --git a/src/sysdep.c b/src/sysdep.c
index f6c0ddee01..9111f1863e 100644
--- a/src/sysdep.c
+++ b/src/sysdep.c
@@ -2892,7 +2892,7 @@ list_system_processes (void)
process. */
procdir = build_string ("/proc");
match = build_string ("[0-9]+");
- proclist = directory_files_internal (procdir, Qnil, match, Qt, false, Qnil);
+ proclist = directory_files_internal (procdir, Qnil, match, Qt, false, Qnil, Qnil);
/* `proclist' gives process IDs as strings. Destructively convert
each string into a number. */
diff --git a/test/src/dired-tests.el b/test/src/dired-tests.el
new file mode 100644
index 0000000000..3b739e59cc
--- /dev/null
+++ b/test/src/dired-tests.el
@@ -0,0 +1,92 @@
+;;; dired-tests.el --- Tests for directory-files in dired.c -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2015-2020 Free Software Foundation, Inc.
+
+;; Author: Arthur Miller
+;; Keywords:
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program. If not, see .
+
+;;; Commentary:
+
+;;
+
+;;; Code:
+(require 'ert)
+
+(ert-deftest directory-files-tests ()
+ (let ((name (expand-file-name "directory-files-test"
+ (temporary-file-directory)))
+ ;; nodots expression from dired+ by Drew A.
+ (nodots "^\\([^.]\\|\\.\\([^.]\\|\\..\\)\\).*"))
+
+ (message name)
+ (when (file-directory-p name)
+ (delete-directory name t))
+ (make-directory name)
+ (when (file-directory-p name)
+ (should (= 2 (length (directory-files name))))
+ (should-not (directory-files name nil nodots t 1))
+ (dolist (file '(a b c d))
+ (make-empty-file (expand-file-name (symbol-name file) name)))
+ (should (= 6 (length (directory-files name))))
+ (should (equal "abcd" (string-join (directory-files name nil
+ nodots) "")))
+ (should (= 2 (length (directory-files name nil "[bc]"))))
+ (should (= 3 (length (directory-files name nil nodots nil 3))))
+ (dolist (file '(5 4 3 2 1))
+ (make-empty-file (expand-file-name (number-to-string file) name)))
+ (should (= 0 (length (directory-files name nil "[0-9]" t -1))))
+ (should (= 5 (length (directory-files name nil "[0-9]" t))))
+ (should (= 5 (length (directory-files name nil "[0-9]" t 50))))
+ )))
+
+(ert-deftest directory-files-and-attributes-tests ()
+ (let ((name (expand-file-name "directory-files-test"
+ (temporary-file-directory)))
+ ;; nodots expression from dired+ by Drew A.
+ (nodots "^\\([^.]\\|\\.\\([^.]\\|\\..\\)\\).*"))
+
+ (message name)
+ (when (file-directory-p name)
+ (delete-directory name t))
+ (make-directory name)
+ (when (file-directory-p name)
+ (should (= 2 (length (directory-files name))))
+ (should-not (directory-files-and-attributes name t nodots t 1))
+ (dolist (file '(a b c d))
+ (make-directory (expand-file-name (symbol-name file) name)))
+ (should (= 6 (length (directory-files-and-attributes name))))
+ (dolist (dir (directory-files-and-attributes name t nodots))
+ (should (file-directory-p (car dir)))
+ (should-not (file-regular-p (car dir))))
+ (should (= 2 (length
+ (directory-files-and-attributes name nil "[bc]"))))
+ (should (= 3 (length
+ (directory-files-and-attributes name nil nodots
+ nil nil 3))))
+ (dolist (file '(5 4 3 2 1))
+ (make-empty-file (expand-file-name (number-to-string file) name)))
+ (should (= 0 (length
+ (directory-files-and-attributes name nil
+ "[0-9]" t 1 -1))))
+ (should (= 5 (length
+ (directory-files-and-attributes name nil "[0-9]" t))))
+ (should (= 5 (length
+ (directory-files-and-attributes name nil
+ "[0-9]" t nil 50))))
+ )))
+
+(provide 'dired-tests)
+;;; dired-tests.el ends here