@defun set-default-file-modes mode
This function sets the default file protection for new files created by
Emacs and its subprocesses. Every file created with Emacs initially has
-this protection. On Unix and GNU/Linux, the default protection is the
-bitwise complement of the ``umask'' value.
+this protection, or a subset of it (@code{write-region} will not give a
+file execute permission even if the default file protection allows
+execute permission). On Unix and GNU/Linux, the default protection is
+the bitwise complement of the ``umask'' value.
The argument @var{mode} must be an integer. On most systems, only the
-low 9 bits of @var{mode} are meaningful.
+low 9 bits of @var{mode} are meaningful. You can use the Lisp construct
+for octal character codes to enter @var{mode}; for example,
+
+@example
+(set-default-file-modes ?\644)
+@end example
Saving a modified version of an existing file does not count as creating
-the file; it does not change the file's mode, and does not use the
-default file protection.
+the file; it preserves the existing file's mode, whatever that is. So
+the default file protection has no effect.
@end defun
@defun default-file-modes