From fce156be903c57e2a370925fbc5995815d88e997 Mon Sep 17 00:00:00 2001
From: vg <vg@devys.org>
Date: Sun, 3 Jun 2018 11:09:27 +0200
Subject: add a battery monitoring script putting pc in hibernate

---
 scripts/critical_hibernate.py | 65 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 scripts/critical_hibernate.py

diff --git a/scripts/critical_hibernate.py b/scripts/critical_hibernate.py
new file mode 100644
index 0000000..7b19978
--- /dev/null
+++ b/scripts/critical_hibernate.py
@@ -0,0 +1,65 @@
+#!/usr/bin/python3
+import os
+import subprocess
+import sys
+import time
+
+# For use with systemd as a service:
+# copy this script to /usr/local/sbin/critical_hibernate.py with:
+# install -m 0755 -o root -g root critical_hibernate.py
+# /usr/local/sbin/critical_hibernate.py
+# and:
+# /etc/systemd/system/critical_hibernate.service
+#
+#   [Service]
+#   ExecStart=/usr/local/sbin/critical_hibernate.py
+#   Restart=on-failure
+#   KillMode=process
+#
+#   [Install]
+#   WantedBy=multi-user.target
+#
+# Then, do a systemctl enable --now critical_hibernate
+
+sysfs_path = '/sys/class/power_supply/BAT0/uevent'
+threshold = 9
+run_hibernate = True
+
+original_print = print
+def flush_print(*args, **kw):
+    original_print(*args, **kw)
+    filelike = kw.get('file', sys.stdout)
+    filelike.flush()
+print = flush_print
+
+try:
+    while True:
+        batfd = None
+        try:
+            batfd = os.open(sysfs_path, os.O_RDONLY)
+            print('monitoring %s' % sysfs_path)
+            while True:
+                uevent_dict = dict((e.split(b'=')
+                                    for e in os.pread(batfd, 1024, 0).split()))
+                capacity = int(uevent_dict[b'POWER_SUPPLY_CAPACITY'])
+                status   = uevent_dict[b'POWER_SUPPLY_STATUS']
+                if status == b'Discharging' and capacity <= threshold:
+                    print('low battery %d <= %d' % (capacity, threshold))
+                    if run_hibernate:
+                        print('running systemctl hibernate')
+                        subprocess.run(['/bin/systemctl', 'hibernate'])
+
+                time.sleep(60)
+        except OSError:
+            print('io error on %s, assume battery changement' % sysfs_path)
+        except FileNotFoundError:
+            print('file %s is missing' % sysfs_path)
+        finally:
+            if batfd is not None:
+                os.close(batfd)
+
+        print('retrying to open %s in 60 seconds' % sysfs_path)
+        time.sleep(60)
+
+except KeyboardInterrupt:
+    print('SIGINT, exiting')
-- 
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