bug#24150: 25.1.50; New command: dired-create-empty-file

[Tino Calancha <tino.calancha@gmail.com>]

Hi all,

It might be useful having a Dired command creating
an empty file with a name provided by the user; something
like 'dired-create-directory' ('+') but for files.

Following patch propose a new command 'dired-create-empty-file'
bound to 'M-+'.

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From 96b5bfe9f33e7fea5296f83649dd4b6a48bafb06 Mon Sep 17 00:00:00 2001
From: Tino Calancha <tino.calancha@gmail.com>
Date: Thu, 4 Aug 2016 22:07:00 +0900
Subject: [PATCH] New command dired-create-empty-file

* lisp/dired-aux.el (dired--create-empty-file-or-directory):
New macro to create a new empty file or directory.
(dired-create-directory): Use it.
(dired-create-empty-file): New command; as 'dired-create-directory'
but it creates an empty file instead of a dir.
* lisp/dired.el (dired-mode-map): Bind 'dired-create-empty-file'
to 'M-+'.
* doc/emacs/dired.texi: Document the new command in the manual.
* etc/NEWS: Add entry for this new feature.
---
  doc/emacs/dired.texi |  6 ++++++
  etc/NEWS             |  5 +++++
  lisp/dired-aux.el    | 50 
++++++++++++++++++++++++++++++++++++--------------
  lisp/dired.el        |  1 +
  4 files changed, 48 insertions(+), 14 deletions(-)

diff --git a/doc/emacs/dired.texi b/doc/emacs/dired.texi
index 2cda51a..c2de114 100644
--- a/doc/emacs/dired.texi
+++ b/doc/emacs/dired.texi
@@ -1410,6 +1410,12 @@ Misc Dired Features
  directory name, and creates that directory.  It signals an error if
  the directory already exists.

+@kindex M-+ @r{(Dired)}
+@findex dired-create-empty-file
+  The command @kbd{M-+} (@code{dired-create-empty-file}) reads a
+file name, and creates an empty file with that name.  It signals
+an error if the file already exists.
+
  @cindex searching multiple files via Dired
  @kindex M-s a C-s @r{(Dired)}
  @kindex M-s a M-C-s @r{(Dired)}
diff --git a/etc/NEWS b/etc/NEWS
index fadf4c2..394b9f8 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -249,6 +249,11 @@ whose content matches a regexp; bound to '% g'.
  ** Dired

  +++
+*** A new command 'dired-create-empty-file' similar as
+'dired-create-directory' but it creates a new empty file;
+bound to 'M-+'.
+
++++
  *** A New option 'dired-always-read-filesystem' default to nil.
  If non-nil, buffers visiting files are reverted before search them;
  for instance, in 'dired-mark-files-containing-regexp' a non-nil value
diff --git a/lisp/dired-aux.el b/lisp/dired-aux.el
index 4732d9c..84b0c35 100644
--- a/lisp/dired-aux.el
+++ b/lisp/dired-aux.el
@@ -1888,24 +1888,46 @@ dired-dwim-target-defaults
        dired-dirs)))


+(defmacro dired--create-empty-file-or-directory (fname &optional 
create-file)
+  "Create an empty file or directory called FNAME.
+If FNAME already exists, signal an error.
+Optional arg CREATE-FILE if non-nil, then create a file.  Otherwise 
create
+a directory. "
+  `(let* ((expanded (directory-file-name (expand-file-name ,fname)))
+          (parent (directory-file-name (file-name-directory expanded)))
+          (try expanded) new)
+     (when ,create-file
+       (setq try parent
+             new expanded))
+     (when (file-exists-p expanded)
+       (error "Cannot create file %s: file exists" expanded))
+     ;; Find the topmost nonexistent parent dir (variable `new')
+     (while (and try (not (file-exists-p try)) (not (equal new try)))
+       (setq new try
+             try (directory-file-name (file-name-directory try))))
+     (cond (,create-file
+            (unless (file-exists-p parent)
+              (make-directory parent t))
+            (write-region "" nil expanded nil 0))
+           (t
+            (make-directory expanded t)))
+     (when new
+       (dired-add-file new)
+       (dired-move-to-filename))))
+
  ;;;###autoload
  (defun dired-create-directory (directory)
    "Create a directory called DIRECTORY.
  If DIRECTORY already exists, signal an error."
-  (interactive
-   (list (read-file-name "Create directory: " 
(dired-current-directory))))
-  (let* ((expanded (directory-file-name (expand-file-name directory)))
-	 (try expanded) new)
-    (if (file-exists-p expanded)
-	(error "Cannot create directory %s: file exists" expanded))
-    ;; Find the topmost nonexistent parent dir (variable `new')
-    (while (and try (not (file-exists-p try)) (not (equal new try)))
-      (setq new try
-	    try (directory-file-name (file-name-directory try))))
-    (make-directory expanded t)
-    (when new
-      (dired-add-file new)
-      (dired-move-to-filename))))
+  (interactive (list (read-file-name "Create directory: ")))
+  (dired--create-empty-file-or-directory directory))
+
+;;;###autoload
+(defun dired-create-empty-file (file)
+  "Create an empty file called FILE.
+If FILE already exists, signal an error."
+  (interactive (list (read-file-name "Create empty file: ")))
+  (dired--create-empty-file-or-directory file 'create-file))

  (defun dired-into-dir-with-symlinks (target)
    (and (file-directory-p target)
diff --git a/lisp/dired.el b/lisp/dired.el
index 7ead087..df5a61c 100644
--- a/lisp/dired.el
+++ b/lisp/dired.el
@@ -1554,6 +1554,7 @@ dired-mode-map
      (define-key map "x" 'dired-do-flagged-delete)
      (define-key map "y" 'dired-show-file-type)
      (define-key map "+" 'dired-create-directory)
+    (define-key map "\M-+" 'dired-create-empty-file)
      ;; moving
      (define-key map "<" 'dired-prev-dirline)
      (define-key map ">" 'dired-next-dirline)
-- 
2.8.1


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In GNU Emacs 25.1.50 (x86_64-pc-linux-gnu, GTK+ Version 3.20.6)
  of 2016-08-03 built
Repository revision: 7f9721d3990155bae83e4e4840f0ff4913868d50