Add xpra sessions to `w`

[stdedos]

I don't know how much sense would it make: Could we add the expra sessions to the w output?

$ w
 11:06:39 up 6 days, 19:02, 17 users,  load average: 1,18, 1,61, 1,60
USER     TTY      FROM             LOGIN@   IDLE   JCPU   PCPU WHAT
user_li tty7     :0               05Μάρ20  6days 12:34m  7.20s /sbin/upstart --user
user_li pts/19   tmux(5311).%2    05Μάρ20  5days 14.03s 13.97s /usr/bin/ssh
user_li pts/20   tmux(5311).%7    05Μάρ20  6days 15:09  15:08  python3 /home/user_li/Documents/WorkBulk/Ubuntu/vlc_write_played_song.py
user_li pts/21   tmux(5311).%3    05Μάρ20  6days 19.30s 19.22s /usr/bin/ssh
user_li pts/22   tmux(5311).%4    05Μάρ20  6days 14.01s 13.95s /usr/bin/ssh
user_li pts/23   tmux(5311).%5    05Μάρ20  6days 14.05s 13.98s /usr/bin/ssh
user_li pts/26   tmux(5311).%8    05Μάρ20  5days  6:47   6:47  /snap/libreoffice/173/lib/libreoffice/program/soffice.bin --calc 
user_li pts/33   tmux(5311).%9    05Μάρ20  6days  0.86s  0.81s /home/user_li/.installs/jupyter/.venv/bin/python3.7 /home/user_li/.installs/jupyter/.venv/bin/jupyter-notebook
user_li pts/40   tmux(5311).%10   06Μάρ20 22:07m  2.21s  2.07s /usr/bin/ssh
user_li pts/41   tmux(5311).%11   06Μάρ20 23:44m  2.60s  2.41s /usr/bin/ssh
user_li pts/42   tmux(5311).%12   06Μάρ20 23:45m  2.15s  2.04s /usr/bin/ssh
user_li pts/43   tmux(5311).%13   06Μάρ20 22:27m  0.12s  0.12s bash
user_li pts/44   tmux(5311).%15   06Μάρ20  2days 12.90s 12.85s /usr/bin/ssh
user_li pts/45   tmux(5311).%16   06Μάρ20  6days 17.52s 17.47s /usr/bin/ssh
user_li pts/46   tmux(5311).%17   06Μάρ20  6days 12.86s 12.81s /usr/bin/ssh
user_li pts/47   tmux(5311).%18   06Μάρ20  5days  0.67s  0.67s bash
user_li pts/51   tmux(5311).%30   Παρ16    2days  0.41s  0.41s /bin/bash

tmux already has its pane (and sessions?) there, so the parent of each xpra screen could be added too

[Antoine Martin]

For now, use start-via-proxy=yes with your server start commands, the pam session will create one for you.
(make sure the proxy server is running)

We could add a call to pututline when starting a server session, but ​python-utmp is not cooperating:

from utmp import UtmpRecord
r = UtmpRecord()
r.pututline(dict(ut_type=utmp.USER_PROCESS, ut_pid=9999, ut_line="",  ut_id=":10", ut_user="antoine", ut_host="desktop", ut_exit=(0, 0), ut_session=8888, ut_tv=(1583937777, 444444), ut_addr_v6=(0, 0, 0, 0)))
r.endutent()

So unless someone can figure it out, it won't happen anytime soon.

[migration script]

this ticket has been moved to: ​https://github.com/Xpra-org/xpra/issues/2637