add zzz suspend/hibernate utility

taken from https://github.com/voidlinux/void-runit which is under the
following license:
void-runit is in the public domain.

To the extent possible under law, the creator of this work has waived
all copyright and related or neighboring rights to this work.

http://creativecommons.org/publicdomain/zero/1.0/

KEEP/bin/zzz

@@ -0,0 +1,64 @@
+#!/bin/sh
+# zzz - really simple suspend script
+
+USAGE="Usage: ${0##*/} [-nSzZR]
+   -n   dry run (sleep for 5s instead of suspend/hibernate)
+   -S   Low-power idle (ACPI S0)
+   -z   suspend to RAM (ACPI S3) [DEFAULT for zzz(8)]
+   -Z   hibernate to disk & power off (ACPI S4) [DEFAULT for ZZZ(8)]
+   -R   hibernate to disk & reboot
+   -H   hibernate to disk & suspend (aka suspend-hybrid)"
+
+fail() { echo ${0##*/}: 1>&2 "$*"; exit 1; }
+
+export ZZZ_MODE=suspend
+export ZZZ_HIBERNATE_MODE=platform
+
+case "$0" in
+  *ZZZ) ZZZ_MODE=hibernate;;
+esac
+
+while getopts hnSzHRZ: opt; do
+  case "$opt" in
+    n) ZZZ_MODE=noop;;
+    S) ZZZ_MODE=standby;;
+    z) ZZZ_MODE=suspend;;
+    Z) ZZZ_MODE=hibernate;;
+    R) ZZZ_MODE=hibernate; ZZZ_HIBERNATE_MODE=reboot;;
+    H) ZZZ_MODE=hibernate; ZZZ_HIBERNATE_MODE=suspend;;
+    [h?]) fail "$USAGE";;
+  esac
+done
+shift $((OPTIND-1))
+
+case "$ZZZ_MODE" in
+  suspend) grep -q mem /sys/power/state || fail "suspend not supported";;
+  hibernate) grep -q disk /sys/power/state || fail "hibernate not supported";;
+esac
+
+test -w /sys/power/state || fail "sleep permission denied"
+
+(
+flock -n 9 || fail "another instance of zzz is running"
+
+printf "Zzzz... "
+
+for hook in /etc/zzz.d/suspend/*; do
+  [ -x "$hook" ] && "$hook"
+done
+
+case "$ZZZ_MODE" in
+  standby) printf freeze >/sys/power/state || fail "standby failed";;
+  suspend) printf mem >/sys/power/state || fail "suspend failed";;
+  hibernate)
+	echo $ZZZ_HIBERNATE_MODE >/sys/power/disk
+	printf disk >/sys/power/state || fail "hibernate failed";;
+  noop) sleep 5;;
+esac
+
+for hook in /etc/zzz.d/resume/*; do
+  [ -x "$hook" ] && "$hook"
+done
+
+echo "yawn."
+) 9</sys/power

KEEP/share/man/man8/zzz.8

@@ -0,0 +1,94 @@
+.Dd July 25, 2014
+.Dt ZZZ 8
+.Os Linux
+.Sh NAME
+.Nm zzz ,
+.Nm ZZZ
+.Nd suspend or hibernate your computer
+.Sh SYNOPSIS
+.Nm zzz
+.Op Fl nSzZRH
+.Nm ZZZ
+.Op Fl nSzZRH
+.Sh DESCRIPTION
+.Nm
+is a simple script to suspend or hibernate your computer.
+It supports hooks before and after suspending.
+.Bl -tag -width indent
+.It Fl n
+dry-run mode.
+Instead of performing an ACPI action,
+.Nm
+will just sleep for a few seconds.
+.It Fl S
+Enter low-power idle mode (ACPI S0, kernel name "freeze").
+.It Fl z
+Enter suspend to RAM mode (ACPI S3, kernel name "mem").
+This is the default for
+.Nm zzz .
+.It Fl Z
+Enter hibernate to disk mode (ACPI S4, kernel name "disk") and power off.
+This is the default for
+.Nm ZZZ .
+.It Fl R
+Enter hibernate to disk mode and reboot.
+This can be used to switch operating systems.
+.It Fl H
+Enter hibernate to disk mode and suspend.
+This is also know as suspend-hybrid.
+.El
+.Sh FILES
+Before suspending,
+.Nm zzz
+runs the executable files in
+.Pa /etc/zzz.d/suspend
+in alphanumeric order.
+After suspending,
+.Nm zzz
+runs the executable files in
+.Pa /etc/zzz.d/resume
+in alphanumeric order (not in reverse order!).
+.Pp
+The environment variable
+.Ev ZZZ_MODE
+can be used in these hooks to differentiate between
+.Ic standby ,
+.Ic suspend ,
+and
+.Ic resume .
+.Sh DIAGNOSTICS
+.Bl -tag -width indent
+.It suspend/hibernate not supported
+The hardware does not support ACPI S3/S4 with this kernel.
+.It sleep permission denied
+You lack sufficent privilege to write to
+.Pa /sys/power/state .
+.It another instance of zzz is running
+.Nm
+locks
+.Pa /sys/power
+during operation.
+Perhaps a hook is stuck?
+.It Zzzz... yawn.
+The system has woken up again.
+Everything is fine.
+You feel refreshed.
+.Sh SEE ALSO
+.Xr pm-action 8 ,
+.Xr s2disk 8 ,
+.Xr s2ram 8 ,
+OpenBSD's
+.Xr apm 8
+.Sh HISTORY
+A similar
+.Nm apm
+command appeared in
+.Nx 1.3
+and
+.Ox 1.2 .
+.Sh AUTHOR
+.An Christian Neukirchen ,
+.Mt chneukirchen@gmail.com .
+.Sh LICENSE
+.Nm
+is in the public domain.