The xhost program can disable or enable access control for all computers or certain computers. Owners of ``magic cookies'' always have access regardless of the setting for computers.
To check which computers have access to your display:
$xhost access control enabled, only authorized clients can connect $
To allow a certain computer to use your display:
$xhost +platon platon being added to access control list $xhost access control enabled, only authorized clients can connect INET:platon $
To allow all computers to use your display, i.e. disable all access control:
$xhost + access control disabled, clients can connect from any host $xhost access control disabled, clients can connect from any host INET:platon $
To cancel access control for all computers except explicitly named ones:
$xhost - access control enabled, only authorized clients can connect $xhost access control enabled, only authorized clients can connect INET:platon $
To cancel access control for named computers:
$xhost -platon platon being removed from access control list $xhost access control enabled, only authorized clients can connect $
As giving access control to whole computers leaves a security loophole, access control can be done by giving out ``magic cookies''.