(file-name-invalid-regexp): New variable, moved here from arc-mode.el

1 files changed, 12 insertions, 0 deletions

diff --git a/lisp/files.el b/lisp/files.el
index d0ecd6c2922..7d1ffa81235 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -170,6 +170,18 @@ If the buffer is visiting a new file, the value is nil.")
 (defvar buffer-file-numbers-unique (not (memq system-type '(windows-nt)))
   "Non-nil means that buffer-file-number uniquely identifies files.")
 
+(defvar file-name-invalid-regexp
+  (cond ((and (eq system-type 'ms-dos) (not (msdos-long-file-names)))
+         (concat "\\(^\\([A-z]:\\)?/?.*:\\)\\|"   ; colon except after drive
+                 "[+, ;=|<>\"?*]\\|\\[\\|\\]\\|"  ; invalid characters
+                 "\\(/\\.\\.?[^/]\\)\\|"          ; leading dots
+                 "\\(/[^/.]+\\.[^/.]*\\.\\)"))    ; more than a single dot
+        ((memq system-type '(ms-dos windows-nt))
+         (concat "\\(^\\([A-z]:\\)?/?.*:\\)\\|"   ; colon except after drive
+                 "[|<>\"?*]"))                    ; invalid characters
+        (t "[\000]"))
+  "Regexp recognizing file names which aren't allowed by the filesystem.")
+
 (defcustom file-precious-flag nil
   "*Non-nil means protect against I/O errors while saving files.
 Some modes set this non-nil in particular buffers.