On Tue, 27 Jun 2017, Tom H wrote:

> On Tue, Jun 20, 2017 at 4:38 PM, ToddAndMargo <[log in to unmask]> wrote:
>>
>> I have been using UNIX and Linux for over 25 years and did not realize
>> X11 has four clipboards. I recently discovered the Secondary Selection
>> keyboard.
>>
>> It really saves a bunch of time when I am programming as I don't lose
>> my cursor's hot spot.
>>
>> Here is a great 8 minute video demonstrating all four clipboards. It
>> is must learn for anyone using Linux.
>>
>> http://www.cs.man.ac.uk/~chl/Secondary-Selection.mp4
>>
>> To support this clipboard, your program has to use the GTK Toolkit.
>
> Thanks. I didn't know about this secondary clipboard. I've just tried
> it on my laptop running Ubuntu 17.10 but it didn't work. I suspect
> that it's been deep-sixed in Gnome Shell and Unity.

I was interested in the secondary clipboard too, and looked at
   http://www.cs.man.ac.uk/~chl/secondary-selection.html
which makes clear that this is not a standard gtk feature;
there are experimental modified gtk3 libraries which support
secondary selection (no source yet).

gtk3 means it doesn't run on SL6, so I haven't been able to explore 
further.

-- 
Andrew C Aitchison			Cambridge, UK