- added README.md

- added systemd service descriptors
- new features in gpio_trigger.py:
  - support waiting for a hold period (-H)
  - added option to ignore command's result code (-i)
  - added variable subtitution in the arguments (%PIN% and %STATE%)

rpi_poweroff_button.service

@@ -0,0 +1,40 @@
+#
+# rpi_poweroff_button.service – Systemd service to implement a poweroff button
+#
+# Version 1.0, latest version, documentation and bugtracker available at:
+#		https://gitlab.lindenaar.net/scripts/raspberrypi
+#
+# Copyright (c) 2019 Frederik Lindenaar
+#
+# This script is free software: you can redistribute and/or modify it under the
+# terms of version 3 of the GNU General Public License as published by the Free
+# Software Foundation, or (at your option) any later version of the license.
+#
+# This script is distributed in the hope that it will be useful but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
+# A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program.  If not, visit <http://www.gnu.org/licenses/> to download it.
+#
+
+# Please note this requires gpio_trigger.py installed in /usr/local/sbin, see:
+# https://frederik.lindenaar.nl/2019/10/23/raspberry-pi-power-off-button.html
+
+# To install copy to /etc/systemd/system/rpi_poweroff_button.service
+# enable it to start during boot with:  systemctl enable rpi_poweroff_button
+# temporarily enable with:              service rpi_poweroff_button start
+# temporarily disable with:             service rpi_poweroff_button stop
+# disable starting during boot with:    systemctl disable rpi_poweroff_button
+
+[Unit]
+Description=Power-off button on GPIO
+
+[Service]
+Type=idle
+ExecStart=/usr/local/sbin/gpio_trigger.py --hold 5000 poweroff
+Restart=always
+RestartSec=30
+
+[Install]
+WantedBy=default.target