summaryrefslogtreecommitdiff
path: root/doc/lispref/files.texi
diff options
context:
space:
mode:
Diffstat (limited to 'doc/lispref/files.texi')
-rw-r--r--doc/lispref/files.texi17
1 files changed, 17 insertions, 0 deletions
diff --git a/doc/lispref/files.texi b/doc/lispref/files.texi
index 1e05153f3c0..ddc1d05c1ca 100644
--- a/doc/lispref/files.texi
+++ b/doc/lispref/files.texi
@@ -1314,6 +1314,20 @@ on the 19th, @file{aug-20} was written on the 20th, and the file
@end example
@end defun
+@defun file-has-changed-p filename tag
+This function returns non-@code{nil} if the time stamp of
+@var{filename} has changed since the last call. When called for the
+first time for some @var{filename}, it records the last modification
+time and size of the file, and returns non-@code{nil} when
+@var{filename} exists. Thereafter, when called for the same
+@var{filename}, it compares the current time stamp and size with the
+recorded ones, and returns non-@code{nil} only if either the time
+stamp or the size (or both) are different. This is useful when a Lisp
+program wants to re-read a file whenever it changes. With an optional
+argument @var{tag}, which must be a symbol, the size and modification
+time comparisons are limited to calls with the same tag.
+@end defun
+
@defun file-attributes filename &optional id-format
@anchor{Definition of file-attributes}
This function returns a list of attributes of file @var{filename}. If
@@ -2083,6 +2097,9 @@ directory. Therefore, Emacs considers a file name as having two main
parts: the @dfn{directory name} part, and the @dfn{nondirectory} part
(or @dfn{file name within the directory}). Either part may be empty.
Concatenating these two parts reproduces the original file name.
+@footnote{Emacs follows the GNU convention to use the term @emph{file name}
+instead of the term @emph{pathname}. We use the term @emph{path} only for
+search paths, which are lists of directory names.}
On most systems, the directory part is everything up to and including
the last slash (backslash is also allowed in input on MS-DOS or