From a3b193516f991ceaf79d33c6158dd7ef060c7bce Mon Sep 17 00:00:00 2001 From: Michael Albinus Date: Sat, 9 Mar 2019 09:47:07 +0100 Subject: [PATCH] Mention empty strings in file name expansion, emacs lisp reference * doc/lispref/files.texi (Files, File Name Expansion): Mention also empty strings. --- doc/lispref/files.texi | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/doc/lispref/files.texi b/doc/lispref/files.texi index 403a21b3365..380e0543ddd 100644 --- a/doc/lispref/files.texi +++ b/doc/lispref/files.texi @@ -16,7 +16,7 @@ described in @ref{Backups and Auto-Saving}. names. A file name is a string. Most of these functions expand file name arguments using the function @code{expand-file-name}, so that @file{~} is handled correctly, as are relative file names (including -@file{../}). @xref{File Name Expansion}. +@file{../} and the empty string). @xref{File Name Expansion}. In addition, certain @dfn{magic} file names are handled specially. For example, when a remote file name is specified, Emacs accesses the @@ -2409,6 +2409,17 @@ This is for the sake of filesystems that have the concept of a superroot above the root directory @file{/}. On other filesystems, @file{/../} is interpreted exactly the same as @file{/}. +Expanding @file{.} or the empty string returns the default directory: + +@example +@group +(expand-file-name "." "/usr/spool/") + @result{} "/usr/spool" +(expand-file-name "" "/usr/spool/") + @result{} "/usr/spool" +@end group +@end example + Note that @code{expand-file-name} does @emph{not} expand environment variables; only @code{substitute-in-file-name} does that: -- 2.39.2