The xauth command is used to display and edit authentication information used to connect to an X server. This command is used to manage cookies, which are used by the X server to authenticate connections from clients. The xauth command is used to add and remove cookies, as well as to list the cookies that are currently in use.
Overview
The xauth command can be used to perform a variety of tasks related to X server authentication. Here are some of the most common use cases:
Displaying Cookies
To display the cookies that are currently in use, you can use the following command:
xauth list
This will display a list of cookies in the following format:
<hostname>/unix:0 MIT-MAGIC-COOKIE-1 <cookie>
Adding Cookies
To add a new cookie, you can use the following command:
xauth add <hostname>/unix:0 MIT-MAGIC-COOKIE-1 <cookie>
Replace <hostname> with the name of the host where the X server is running, and <cookie> with the value of the cookie you want to add. You can generate a new cookie value using the mcookie command.
Removing Cookies
To remove a cookie, you can use the following command:
xauth remove <hostname>/unix:0
Replace <hostname> with the name of the host where the X server is running.
Options
Here are the available options for the xauth command:
| Option | Description |
|---|---|
-f filename |
Use the specified filename instead of the default .Xauthority. |
-v |
Verbose output. |
Troubleshooting Tips
Here are some common issues you may encounter when using the xauth command:
“Unable to open display”
If you see an error message that says “unable to open display”, it means that the X server is not running or is not accessible. Make sure the X server is running and that you have the correct permissions to access it.
“No protocol specified”
If you see an error message that says “no protocol specified”, it means that the DISPLAY environment variable is not set correctly. Make sure that the DISPLAY variable is set to the correct value, which should be in the format hostname:display_number.screen_number.
Notes
- The
xauthcommand is typically used by system administrators and advanced users who need to manage X server authentication. - Cookies are used to authenticate connections between X clients and the X server. Without authentication, any client could potentially connect to the X server and access sensitive information or perform malicious actions.