arch-wiki-md-repo/wiki/_content/english/Xhost.md

All arch-wiki articles in markdown format, updated every two days.

From Xhost man page:

	The xhost program is used to add and delete host names or user names to the list allowed to make connections to the X server. In the case of hosts, this 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. 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.

See [xhost(1)](https://jlk.fjfi.cvut.cz/arch/manpages/man/xhost.1) for the full info.

## Installation

[Install](/index.php/Install "Install") the [xorg-xhost](https://www.archlinux.org/packages/?name=xorg-xhost) package.

## Usage

To provide access to an application running as sudo or su to the graphical server (aka your X session aka your computer screen), open a terminal and type as your normal user (don't *su -*):

```
$ xhost +local:

```

To get things back to normal, with controlled access to the X screen:

```
$ xhost -

```

## The 'cannot connect to X server :0.0' output

**Warning:** This command disables access control, meaning that any user on the system, or on your network if X is listening on the network, has access to your $DISPLAY without any authentication. This opens a security hole on your system that allows other users to launch applications (including key loggers) on your X server.

The above command **xhost +** will get you rid of that output, albeit momentarily; one way of getting permanently rid of this issue, among many, is to add

```
xhost + >/dev/null

```

to your `~/.bashrc` file. This way, each time you fire up the terminal, the command gets executed. If you do not yet have a .bashrc file in your home directory, it's OK to create one with just this line in it. If you do not add *>/dev/null* then each time you fire a terminal, you will see a non-disruptive message saying: *access control disabled, clients can connect from any host*, which is your confirmation that you can now *sudo <your soft>* without issue.