Document isduid(3).

Tweaks from jmc@
ok jmc@ krw@

src/lib/libutil/Makefile

@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.32 2010/11/15 15:07:40 jsing Exp $
+#	$OpenBSD: Makefile,v 1.33 2010/11/17 10:10:31 jsing Exp $
 #	$NetBSD: Makefile,v 1.8 1996/05/16 07:03:28 thorpej Exp $
 
 LIB=	util
@@ -10,8 +10,8 @@ SRCS=	check_expire.c duid.c getmaxpartitions.c getrawpartition.c login.c \
 	login_fbtab.c uucplock.c fparseln.c opendisk.c pidfile.c \
 	fmt_scaled.c imsg.c imsg-buffer.c
 
-MAN=	check_expire.3 getmaxpartitions.3 getrawpartition.3 login.3 opendev.3 \
-	openpty.3 pw_init.3 pw_lock.3 readlabelfs.3 uucplock.3 \
+MAN=	check_expire.3 getmaxpartitions.3 getrawpartition.3 isduid.3 login.3 \
+	opendev.3 openpty.3 pw_init.3 pw_lock.3 readlabelfs.3 uucplock.3 \
 	fparseln.3 opendisk.3 login_fbtab.3 pidfile.3 fmt_scaled.3 imsg_init.3
 
 MLINKS+=imsg_init.3 imsg_read.3

src/lib/libutil/isduid.3

@@ -0,0 +1,61 @@
+.\" 	$OpenBSD: isduid.3,v 1.1 2010/11/17 10:10:31 jsing Exp $
+.\"
+.\" * Copyright (c) Joel Sing <jsing@openbsd.org>
+.\"
+.\" Permission to use, copy, modify, and distribute this software for any
+.\" purpose with or without fee is hereby granted, provided that the above
+.\" copyright notice and this permission notice appear in all copies.
+.\"
+.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+.\"
+.Dd $Mdocdate: November 17 2010 $
+.Dt ISDUID 3
+.Os
+.Sh NAME
+.Nm isduid
+.Nd disklabel UID test
+.Sh SYNOPSIS
+.Fd #include <util.h>
+.Ft int
+.Fn isduid "char *duid" "int dflags"
+.Sh DESCRIPTION
+The
+.Fn isduid
+function tests the string
+.Fa duid
+to see if it is a valid
+.Xr disklabel 8
+UID.
+The
+.Fa dflags
+are specified using the same flags as used by
+.Xr opendev 3 .
+.Pp
+If the OPENDEV_PART flag is included in
+.Fa dflags
+the disklabel UID must consist of a 16-character hexadecimal string.
+Otherwise the disklabel UID must consist of a 16-character hexidecimal string
+followed by a
+.Sq \&.
+and a partition letter.
+.Sh RETURN VALUES
+The
+.Fn isduid
+function returns non-zero if
+.Fa duid
+is a valid DUID, otherwise zero is returned.
+.Sh SEE ALSO
+.Xr opendev 3 ,
+.Xr disklabel 5 ,
+.Xr disklabel 8
+.Sh HISTORY
+The
+.Fn isduid
+function first appeared in
+.Ox 4.9 .