tests are performed.
@end defun
-@defun file-in-directory-p file dir
-This function returns @code{t} if @var{file} is a file in directory
-@var{dir}, or in a subdirectory of @var{dir}. It also returns
-@code{t} if @var{file} and @var{dir} are the same directory. It
-compares the truenames of the two directories. If @var{dir} does not
-name an existing directory, the return value is @code{nil}.
-@end defun
-
@defun vc-responsible-backend file
This function determines the responsible VC backend of the given
@var{file}. For example, if @file{emacs.c} is a file tracked by Git,
non-@code{nil} if that directory is the one it is looking for.
@end defun
+@cindex parent directory of file
+@cindex ancestor directory of file
+@cindex file, ancestor directory of
+@defun file-in-directory-p file dir
+This function returns @code{t} if @var{file} is a file in directory
+@var{dir}, or in a subdirectory of @var{dir}. It also returns
+@code{t} if @var{file} and @var{dir} are the same directory. It
+compares the truenames of the two directories. If @var{dir} does not
+name an existing directory, the return value is @code{nil}.
+@end defun
+
@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
(equal f1-attr f2-attr))))))
(defun file-in-directory-p (file dir)
- "Return non-nil if FILE is in DIR or a subdirectory of DIR.
-A directory is considered to be \"in\" itself.
-Return nil if DIR is not an existing directory."
+ "Return non-nil if DIR is a parent directory of FILE.
+Value is non-nil if FILE is inside DIR or inside a subdirectory of DIR.
+A directory is considered to be a \"parent\" of itself.
+DIR must be an existing directory, otherwise the function returns nil."
(let ((handler (or (find-file-name-handler file 'file-in-directory-p)
(find-file-name-handler dir 'file-in-directory-p))))
(if handler