#!/bin/ksh

_count=0
_temp=0

sysctl hw.sensors | { while read _sensor _rest; do

    case ${_sensor} in 

      *temp*)

      _t=${_sensor##*=}
      _t=${_t%%.*}

      (( _count += 1 ))
      (( _temp += ${_t} ))
      ;;
    esac

  done
  [[ ${_count} -ne 0 ]] && printf "%2.2s" $(( _temp /= ${_count} ))
}