.\"	$OpenBSD: ns.3,v 1.7 2001/08/02 20:37:35 hugh Exp $
.\"
.\" Copyright (c) 1986, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.Dd June 4, 1993
.Dt NS 3
.Os
.Sh NAME
.Nm ns_addr ,
.Nm ns_ntoa
.Nd Xerox
.Tn NS Ns (tm)
address conversion routines
.Sh SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <netns/ns.h>
.Ft struct ns_addr
.Fn ns_addr "char *cp"
.Ft char *
.Fn ns_ntoa "struct ns_addr ns"
.Sh DESCRIPTION
The routine
.Fn ns_addr
interprets character strings representing
.Tn XNS
addresses, returning binary information suitable
for use in system calls.
The routine
.Fn ns_ntoa
takes
.Tn XNS
addresses and returns
.Tn ASCII
strings representing the address in a
notation in common use in the Xerox Development Environment:
.Bd -filled -offset indent
<network number>.<host number>.<port number>
.Ed
.Pp
Trailing zero fields are suppressed, and each number is printed in hexadecimal,
in a format suitable for input to
.Fn ns_addr .
Any fields lacking super-decimal digits will have a
trailing
.Sq H
appended.
.Pp
Unfortunately, no universal standard exists for representing
.Tn XNS
addresses.
An effort has been made to ensure that
.Fn ns_addr
be compatible with most formats in common use.
It will first separate an address into 1 to 3 fields using a single delimiter
chosen from
period
.Pq Ql \&. ,
colon
.Pq Ql \&: ,
or pound-sign
.Ql # .
Each field is then examined for byte separators (colon or period).
If there are byte separators, each subfield separated is taken to be
a small hexadecimal number, and the entirety is taken as a network-byte-ordered
quantity to be zero extended in the high-network-order bytes.
Next, the field is inspected for hyphens, in which case
the field is assumed to be a number in decimal notation
with hyphens separating the millenia.
Next, the field is assumed to be a number:
It is interpreted
as hexadecimal if there is a leading
.Ql 0x
(as in C),
a trailing
.Sq H
(as in Mesa), or there are any super-decimal digits present.
It is interpreted as octal is there is a leading
.Ql 0
and there are no super-octal digits.
Otherwise, it is converted as a decimal number.
.Sh RETURN VALUES
None.
(See
.Sx BUGS . )
.Sh SEE ALSO
.Xr hosts 5 ,
.Xr networks 5
.Sh HISTORY
The
.Fn ns_addr
and
.Fn ns_toa
functions appeared in
.Bx 4.3 .
.Sh BUGS
The string returned by
.Fn ns_ntoa
resides in a static memory area.
The function
.Fn ns_addr
should diagnose improperly formed input, and there should be an unambiguous
way to recognize this.