xhost display

[pkoukoulis-r]

great, many thanks,

so the above suggestion by steeldriver did the trick:

$ xhost +local:
$ su oracle
$ xclock

[steeldriver]

man 7 Xsecurity doesn't really say a whole lot more, just:

       Server Interpreted
              The  Server  Interpreted  method  provides  two strings to the X
              server for entry in the access control list.  The  first  string
              represents the type of entry, and the second string contains the
              value of the entry.  These strings are interpreted by the server
              and  different  implementations and builds may support different
              types of entries.  The types supported in the sample implementa‐
              tion  are defined in the SERVER INTERPRETED ACCESS TYPES section
              below.   Entries of this type can be manipulated via xhost.  For
              example to add a Server Interpreted entry of type localuser with
              a value of root, the command is xhost +si:localuser:root.

Not sure why it's on my 14.04 system not yours - the manpage is provided by package `xorg-docs-core` - perhaps that got pulled in because I have some X11 dev packages installed

[TheFu]

Checked a few other systems here ... none of the 14.04 systems have it, but my only 16.04 desktop does. Interesting. I install "server" and add the X stuff I want, to it isn't pulled in by the minimal X dependencies, I suppose.

Never noticed anything unexpected missing before. Should probably update my ansible desktop-built playbook for this, just in time for X11 to be replaced.

It has been a few years since I did any X programming, even manually building something with X dependencies.

Main thing is that the OP got a working solution AND I learned a little more.