USSSSR, a UPower/Systemd Screen Saving Sleep Reactor


Copyright (c) 2013, 2022 Vadim Vygonets <[email protected]>

Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
Licensed under ISC License.


Installation:

go get github.com/unixdj/ussssr
go install github.com/unixdj/ussssr


Usage:

ussssr [-b] COMMAND [ARGS...]

USSSSR listens to sleep (suspend, hibernate) events broadcast by
UPower or systemd on D-Bus and reacts to them by running a
command which presumably will activate a screen saver to lock the
screen.

Upon startup USSSSR tries to open the systemd backend; if it's
not available, UPower is tried; if that ain't there either, we
bail out.

In case the systemd backend is chosen, USSSSR inhibits sleep by
taking a delay lock.  Unless the flag -b was passed, USSSSR will
wait until the program finishes before releasing the lock, or
unil it times out (three seconds).  Thus, commands such as
"xset s activate" and "xscreensaver -lock", that activate the
screen saver and exit, should be run in the foreground (i.e.,
don't use -b).

Regardless of whether the commands are run in the foreground or
in the background, no more than one copy of the program will run
at any time.  If a sleep event arrives while the program is
running, the event will be swallowed.