Snow Leopard "safe sleep" tweak

A quick bash script to dynamically adjust the sleep behavior under Snow Leopard - to avoid the expense of maintaining the sleepimage if the battery is above a certain level.

Thanks again to Joe Kissell for the original script from (TidBITS#893/20-Aug-07).

#!/bin/sh

#
# 20090902 mvgfr: rules have changed (ex: hibernatemode; there is no 7) so recode
#                 AND be more fault-tolerant...
#                 (setpoints raised, & cron freq increased, since lately been losing power before sleep)
# 20090901 mvgfr: Snow Leopard now defaults to "Secure Virtual Memory" so change safe mode to 7
#    (need programmatic way to check, anything better than system_profiler?)
# 20090728 mvgfr: reduce setpoints by 10 (%)
# 20070908 mvgfr: impl setpoints, tweak msgs, Trash vs rm, debug...
# original: Joe Kissell ,  (TidBITS#893/20-Aug-07)
#

debugMe="" # simple toggle; empty means NO & anything else means YES

setpointLow=20
setpointHigh=25

MODE=`/usr/bin/pmset -g | awk '/hibernatemode/ { print $2 }'`
LEFT=`/usr/bin/pmset -g batt | grep Internal | awk '{ print $2 }' | awk -F % '{ print $1 }'`

if [ $LEFT == "(removed)" ] ; then LEFT=0; fi # catch case in which no batt is seen

if [ $debugMe ] ; then /usr/bin/logger -t "hibernatemode" "current mode (on entry): $MODE; batt % remaining: $LEFT"; fi

if [ $LEFT -le $setpointLow ] && [ $MODE == 0 ] ; then
  {
  /usr/bin/logger -t "hibernatemode" "Battery level ${LEFT}%; setting hibernatemode ON"
  /usr/bin/pmset -a hibernatemode 3
  }
elif  [ $LEFT -ge $setpointHigh ] && [ $MODE != 0 ]; then
  {
  /usr/bin/logger -t "hibernatemode" "Battery level is ${LEFT}%; setting hibernatemode OFF"
  /usr/bin/pmset -a hibernatemode 0
  mv /var/vm/sleepimage /Users/mvgfr/.Trash
  }
fi

if [ $debugMe ] ; then
    MODE=`/usr/bin/pmset -g | awk '/hibernatemode/ { print $2 }'`;
    LEFT=`/usr/bin/pmset -g batt | grep Internal | awk '{ print $2 }' | awk -F % '{ print $1 }'`;
    /usr/bin/logger -t "hibernatemode" "current mode (on exit): $MODE; batt % remaining: $LEFT";
fi

#end