same effect as renaming, aside from momentary intermediate states.
@end deffn
-@deffn Command copy-file oldname newname &optional ok-if-exists time mustbenew
+@deffn Command copy-file oldname newname &optional ok-if-exists time preserve-uid-gid
This command copies the file @var{oldname} to @var{newname}. An
error is signaled if @var{oldname} does not exist. If @var{newname}
names a directory, it copies @var{oldname} into that directory,
If @var{time} is non-@code{nil}, then this function gives the new file
the same last-modified time that the old one has. (This works on only
some operating systems.) If setting the time gets an error,
-@code{copy-file} signals a @code{file-date-error} error.
+@code{copy-file} signals a @code{file-date-error} error. In an
+interactive call, a prefix argument specifies a non-@code{nil} value
+for @var{time}.
This function copies the file modes, too.
-In an interactive call, a prefix argument specifies a non-@code{nil}
-value for @var{time}.
-
-The argument @var{mustbenew} controls whether an existing file can be
-overwritten. It works like the similarly-named argument of
-@code{write-region} (@pxref{Writing to Files, mustbenew}).
+If argument @var{preserve-uid-gid} is @code{nil}, we let the operating
+system decide the user and group ownership of the new file (this is
+usually set to the user running Emacs). If @var{preserve-uid-gid} is
+non-@code{nil}, we attempt to copy the user and group ownership of the
+file. This works only on some operating systems, and only if you have
+the correct permissions to do so.
@end deffn
@deffn Command make-symbolic-link filename newname &optional ok-if-exists