message: compute the disk capacity based on block sizes and counts so ha terabyte capacity drives do not break the script
diff: CPU_SPEED=`bc <<< "scale=2; ($(sysctl -in hw.cpufrequency) / 100000000) / 10"`
  CPU_CORE=$( sysctl -in machdep.cpu.core_count )
  - DISK_TOTAL=`df -H $PWD | grep /dev | tr -s ' ' | cut -d\ -f2 | sed 's/[^0-9]//'`
  - DISK_AVAIL=`df -H $PWD | grep /dev | tr -s ' ' | cut -d\ -f4 | sed 's/[^0-9]//'`
  + blksize=`df . | head -1 | awk '{print $2}' | cut -d- -f1`
  + gbfactor=$(( 1073741824 / $blksize ))
  + total_blks=`df . | tail -1 | awk '{print $2}'`
  + avail_blks=`df . | tail -1 | awk '{print $4}'`
  + DISK_TOTAL=$(($total_blks / $gbfactor ))
  + DISK_AVAIL=$(($avail_blks / $gbfactor ))
  printf "\n\tOS name: $ARCH\n"
  printf "\tOS Version: ${OS_VER}\n"
  