How do I create the .Xauthority file?

I don't have a .Xauthority file in my home folder. I want to create it, please tell me the steps to do so in ubuntu 10.10.

Thank You!

In Ubuntu 10.10 there's no longer a ~/.Xauthority file. Instead you'll find the equivalent in

/var/run/gdm/auth-for-<USER>-<RANDOM_CHARACTERS>/database

which will be re-created with new random characters on every session start. You can get its name via the $XAUTHORITY environment variable.

If you need a ~/.Xauthority file to be present, I guess you can simply create a symbolic link to $AUTHORITY on every session start:

1. Open System > Preferences > Startup Applications

2. Click on Add :
   

   • Name: Xauthority
   • Command: /bin/bash -c 'ln -s -f "$XAUTHORITY" ~/.Xauthority'
   • Comment: Creates a symbolic link from ~/.Xauthority to $XAUTHORITY

   and add the entry by clicking on Add.

3. Now every time you log in, it should create the link to the current authority file.

(there indeed appears to be .Xauthority files in Ubuntu 14.10, so I don't know, per the accepted answer, if they went away and came back?)

Probably solved a long time ago but for completeness, when you ssh to a remote system, use:

ssh -X user@remote

You will get a complaint that the .Xauthority file did not exist and also find it was just created. This is dependent some settings in /etc/ssh/sshd_config:

X11Forwarding yes 
X11DisplayOffset 10 
X11UseLocalhost yes

Refer to http://ubuntuforums.org/showthread.php?t=1863739 where I was able to confirm my own experience with this errant error.

While you are checking / updating /etc/ssh/sshd_config make sure root login is disallowed, just a good practice:

PermitRootLogin no