ENH allow screenlocker to also suspend

dot_bin/executable_screenlock

@@ -1,6 +1,8 @@
 #! /bin/bash
 
-## lock the screen using i3lock
+## lock the screen using i3lock (and maybe suspend)
+
+## usage: screenlock [SUSPEND]
 
 # WORKAROUND make the date show up in the right place on 2+ monitor setups
 # I want it to only show up on the primary screen, so use xrandr to get the
@@ -12,6 +14,7 @@ xpos=$(echo "$geometry" | cut -f2 -d" ")
 xoffset=$(("$xpos" + "$width" / 2))
 datepos="$xoffset:600"
 
+# lock and fork so we can suspend with the screen locked
 i3lock --color=000000 \
        --pass-media-keys \
        --nofork \
@@ -42,4 +45,17 @@ i3lock --color=000000 \
        --wrong-size=72 \
        --verif-size=72 \
        --radius=300 \
-       --ring-width=25
+       --ring-width=25 &
+
+# suspend if we want, and if this machine is currently using a battery
+batpath=/sys/class/power_supply/BAT0/status
+
+if [ -f "$batpath" ] && \
+       [ "$(cat $batpath)" == "Discharging" ] && \
+       [ "$1" == "true" ]; then
+    systemctl suspend
+fi
+
+# block until the screen is unlocked (since xss-lock expects the locker to exit
+# only when unlocked)
+wait