4.3BSD-UWisc/man/mann/xhost.n

.TH XHOST 1 "25 January 1986" "X Version 10"
.SH NAME
xhost - X window system access control program
.SH SYNOPSIS
.B xhost
[+-]host ...
.SH DESCRIPTION
.I Xhost
is used to add and delete hosts to the list of machines X will accept
connections from.
This is an elementary form of privacy control, since otherwise X would
be willing to create windows for anyone on the internet.
It is only sufficient for a workstation (single user) environment,
though it does limit the worst abuses.
.PP
If you want to set up hosts that you always trust, you can
specify them in your login file, or you can specify the hosts
in the file \fI/etc/X*.hosts\fP,
where * is the number of the display on the machine.
.PP
Specifying a host name (with an optional leading plus sign)
adds that host to the list; use a leading minus sign to delete
a host.
.PP
DECnet nodes should be specified as names with trailing ``::''.
.PP
This program can only be executed on the machine the display is
connected to.
.PP
It is possible to remove the current host from the access list. 
Be warned that you can't undo this without logging out.
.PP
.I Xhost
with no arguments will print the current hosts allowed to access your
display.
.SH FILES
/etc/X*.hosts
.SH "SEE ALSO"
X(8C), xterm(1)
.SH ENVIRONMENT
DISPLAY	-	To find out which X you are using.
.SH AUTHOR
Copyright 1985 by Massachusetts Institute of Technology.
.br
See \fIX(1)\fP for a complete copyright notice.
.br
Bob Scheifler, MIT Laboratory for Computer Science,
Jim Gettys, MIT Project Athena (DEC).