directory(3): caveats for seekdir.

- If the directory being read is altered, past telldir results are
  (potentially) invalidated. Don't promise that they'll work.

- There is no way to detect failure. (It returns void, and while it
  may set errno, the main failure path in the actual implementation
  does not, so even setting errno to 0 beforehand doesn't work.)

Fix a typo elsewhere while passing through. Bump date.

Author: sauclovian

lib/libc/gen/directory.3

@@ -1,4 +1,4 @@
-.\"	$NetBSD: directory.3,v 1.43 2021/02/17 23:51:04 dholland Exp $
+.\"	$NetBSD: directory.3,v 1.44 2026/01/22 04:01:14 dholland Exp $
 .\"
 .\" Copyright (c) 1983, 1991, 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -29,7 +29,7 @@
 .\"
 .\"     @(#)directory.3	8.1 (Berkeley) 6/4/93
 .\"
-.Dd February 17, 2021
+.Dd January 21, 2026
 .Dt DIRECTORY 3
 .Os
 .Sh NAME
@@ -216,6 +216,13 @@ from which they are derived.
 If the directory is closed and then reopened, the
 .Fn telldir
 value cannot be re-used.
+If the directory is altered from the same or another process, the
+.Fn telldir
+value becomes invalid.
+.Pp
+.Fn seekdir
+returns no value.
+There is no supported way to detect if the operation succeeded.
 .It Fn rewinddir "dirp"
 The
 .Fn rewinddir
@@ -321,7 +328,7 @@ When a file descriptor is used to implement the directory stream, the
 .Fn closedir
 function behaves as if the
 .Dv FD_CLOEXEC
-had been set for the file descriptor.
+flag had been set for the file descriptor.
 In other words, it is mandatory that
 .Fn closedir
 deallocates the file descriptor.