(directory-free-space-program): Mention

file-system-info in the doc string.
(get-free-disk-space): New function; code moved from insert-directory.
(insert-directory): Call get-free-disk-space to get the amount of free space.

diff --git a/lisp/files.el b/lisp/files.el
index 8c89bc8595cffd5264346853cceed347bb843718..7e0f24268e7096352041e479d30a4a55a3e1bc82 100644 (file)
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -3561,7 +3561,10 @@ We assume the output has the format of `df'.
 The value of this variable must be just a command name or file name;
 if you want to specify options, use `directory-free-space-args'.
 
-A value of nil disables this feature."
+A value of nil disables this feature.
+
+If the function `file-system-info' is defined, it is always used in
+preference to the program given by this variable."
   :type '(choice (string :tag "Program") (const :tag "None" nil))
   :group 'dired)
 
@@ -3570,6 +3573,42 @@ A value of nil disables this feature."
   :type 'string
   :group 'dired)
 
+(defun get-free-disk-space (dir)
+  "Return the mount of free space on directory DIR's file system.
+The result is a string that gives the number of free 1KB blocks,
+or nil if the system call or the program which retrieve the infornmation
+fail.
+
+This function calls `file-system-info' if it is available, or invokes the
+program specified by `directory-free-space-program' if that is non-nil."
+  ;; Try to find the number of free blocks.  Non-Posix systems don't
+  ;; always have df, but might have an equivalent system call.
+  (if (fboundp 'file-system-info)
+      (let ((fsinfo (file-system-info dir)))
+       (if fsinfo
+           (format "%.0f" (/ (nth 2 fsinfo) 1024))))
+    (save-match-data
+      (with-temp-buffer
+       (when (and directory-free-space-program
+                  (zerop (call-process directory-free-space-program
+                                       nil t nil
+                                       directory-free-space-args
+                                       dir)))
+         ;; Usual format is a header line followed by a line of
+         ;; numbers.
+         (goto-char (point-min))
+         (forward-line 1)
+         (if (not (eobp))
+             (progn
+               ;; Move to the end of the "available blocks" number.
+               (skip-chars-forward "^ \t")
+               (forward-word 3)
+               ;; Copy it into AVAILABLE.
+               (let ((end (point)))
+                 (forward-word -1)
+                 (buffer-substring (point) end)))))))))
+
+
 ;; insert-directory
 ;; - must insert _exactly_one_line_ describing FILE if WILDCARD and
 ;;   FULL-DIRECTORY-P is nil.
@@ -3689,38 +3728,12 @@ If WILDCARD, it also runs the shell specified by `shell-file-name'."
            (goto-char (point-min))
            ;; First find the line to put it on.
            (when (re-search-forward "^total" nil t)
-             ;; Try to find the number of free blocks.
-             ;; Non-Posix systems don't always have df,
-             ;; but might have an equivalent system call.
-             (if (fboundp 'file-system-info)
-                 (let ((fsinfo (file-system-info ".")))
-                   (if fsinfo
-                       (setq available (format "%.0f" (/ (nth 2 fsinfo) 1024)))))
-               (save-match-data
-                 (with-temp-buffer
-                   (when (and directory-free-space-program
-                              (zerop (call-process directory-free-space-program
-                                                   nil t nil
-                                                   directory-free-space-args
-                                                   ".")))
-                     ;; Usual format is a header line
-                     ;; followed by a line of numbers.
-                     (goto-char (point-min))
-                     (forward-line 1)
-                     (if (not (eobp))
-                         (progn
-                           ;; Move to the end of the "available blocks" number.
-                           (skip-chars-forward "^ \t")
-                           (forward-word 3)
-                           ;; Copy it into AVAILABLE.
-                           (let ((end (point)))
-                             (forward-word -1)
-                             (setq available (buffer-substring (point) end)))))))))
-             (when available
-               ;; Replace "total" with "used", to avoid confusion.
-               (replace-match "used")
-               (end-of-line)
-               (insert " available " available)))))))))
+             (let ((available (get-free-disk-space ".")))
+               (when available
+                 ;; Replace "total" with "used", to avoid confusion.
+                 (replace-match "used")
+                 (end-of-line)
+                 (insert " available " available))))))))))
 
 (defun insert-directory-safely (file switches
                                     &optional wildcard full-directory-p)