.\" Copyright (c) 1983, 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. 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.
.\"
.\" $FreeBSD: head/share/man/man5/hosts.equiv.5 263142 2014-03-14 03:07:51Z eadler $
.\"
.Dd December 25, 2013
.Dt HOSTS.EQUIV 5
.Os
.Sh NAME
.Nm hosts.equiv ,
.Nm .rhosts
.Nd trusted remote host and user name data base
.Sh DESCRIPTION
The
.Nm
and
.Nm .rhosts
files contain information regarding
trusted hosts and users on the network.
For each host a single line should be present
with the following information:
.Pp
simple
.Bd -unfilled -offset indent
hostname [username]
.Ed
.Pp
or the more verbose
.Bd -unfilled -offset indent
[+-][hostname|@netgroup] [[+-][username|@netgroup]]
.Ed
.Pp
A
.Dq @
indicates a host by netgroup or user by netgroup.
A single
.Dq +
matches all hosts or users.
A host name with a leading
.Dq -
will reject
all matching hosts and all their users.
A user name with leading
.Dq -
will reject all matching users from matching hosts.
.Pp
Items are separated by any number of blanks and/or
tab characters.
A
.Dq #
indicates the beginning of
a comment; characters up to the end of the line are
not interpreted by routines which search the file.
.Pp
Host names are specified in the conventional Internet DNS
dotted-domains
.Dq .\&
(dot) notation using the
.Xr inet_addr 3
routine
from the Internet address manipulation library,
.Xr inet 3 .
Host names may contain any printable
character other than a field delimiter, newline,
or comment character.
.Pp
For security reasons, a user's
.Nm .rhosts
file will be ignored if it is not a regular file, or if it
is not owned by the user, or
if it is writable by anyone other than the user.
.Sh FILES
.Bl -tag -width /etc/hosts.equivxxx -compact
.It Pa /etc/hosts.equiv
The
.Nm
file resides in
.Pa /etc .
.It Pa $HOME/.rhosts
.Nm .rhosts
file resides in
.Pa $HOME .
.El
.Sh EXAMPLES
.Dl bar.com foo
.Pp
Trust user
.Dq foo
from host
.Dq bar.com .
.Pp
.Dl +@allclient
.Pp
Trust all hosts from netgroup
.Dq allclient .
.Pp
.Dl +@allclient -@dau
.Pp
Trust all hosts from netgroup
.Dq allclient
and their users
except users from netgroup
.Dq dau .
.Sh SEE ALSO
.Xr rcp 1 ,
.Xr rlogin 1 ,
.Xr rsh 1 ,
.Xr gethostbyname 3 ,
.Xr inet 3 ,
.Xr innetgr 3 ,
.Xr ruserok 3 ,
.Xr netgroup 5 ,
.Xr ifconfig 8 ,
.Xr yp 8
.Sh BUGS
This manual page is incomplete.
For more information read
the source in
.Pa src/lib/libc/net/rcmd.c
or the SunOS manual page.