On Unix-like operating systems, the xhost command is a server access control program for X. It adds and deletes hostnames or user names to the list allowed to make connections to the X server.

Description

In the case of hosts, xhosts provides a rudimentary form of privacy control and security. It is only sufficient for a workstation (single user) environment, although it does limit the worst abuses in other cases. Environments which require more sophisticated measures should implement the user-based mechanism or use the hooks in the protocol for passing other authentication data to the server.

  • Description
  • Syntax
  • Names
  • Examples
  • Related commands
  • Linux commands help

Syntax

xhost [[+-]name …]

Options

xhost accepts the following command line options described below. For security, the options that affect access control may only run from the “controlling host”. For workstations, this is the same machine as the server. For X terminals, it is the login host.

Names

A complete name has the syntax “family:name” where the families are as follows:

The family is case-insensitive. The format of the name varies with the family.

When Secure RPC is used, the network independent netname (e.g., “nis:unix.uid@domainname”) can be specified, or a local user can be specified with the username and a trailing at sign (e.g., “nis:pat@”). For backward compatibility with pre-R6 xhost, names that contain an at sign (@) are assumed to be in the nis family. Otherwise, they are assumed to be Internet addresses. If compiled to support IPv6, then all IPv4 and IPv6 addresses returned by getaddrinfo are added to the access list in the appropriate inet or inet6 family.

The local family specifies all the local connections at once. However, the server interpreted address “si:localuser:username” can specify a single local user.

Server interpreted addresses consist of a case-sensitive type tag and a string representing a given value, separated by a colon. For example, “si:hostname:almas” is a server interpreted address of type hostname, with a value of almas.

The initial access control list for display number n may be set by the file /etc/Xn.hosts, where n is the display number of the server.

Examples

xhost +

Allow users to connect to the X server.

X — Executable of the X Window System.startx — Start an X Window System session.xorg — The executable of the X Window System server.