Bash time tracker

time_tracker.sh

active_time() {
  # Query display logs
  logs=$(/usr/bin/pmset -g log | grep 'Display is turned')
  # By default Mac turn off monitor after 15 minutes
  timeout=900
  
  # Read logs line by line
  # Line format: 2016-07-12 07:50:02 +0300 Notification        	Display is turned on
  echo "$logs" | while IFS= read -r line; do 
    d=$(echo $line | cut -c 1-19); # extract full date
    ts=$(date -j -f "%Y-%m-%d %H:%M:%S" "$d" "+%s"); # get unix date
    h=$(echo "scale=1; ($ts-$p_ts-900)/3600" | bc -l); # calculate ~ hours
    sd=$(echo $line | cut -c 1-11); # extract day for pretty print
    
    if [ "$h" != "0" ] && [[ "$h" != *"-"* ]]
    then
      echo "$sd - $h hours";
    fi
    
    p_ts=$ts; # remember previous date
  done
}

active_time

# MacBook-Pro:~ buger$ active_time
# 2016-07-12  - .6 hours
# 2016-07-12  - 2.9 hours
# 2016-07-12  - 4.1 hours
# 2016-07-12  - 2.5 hours
# 2016-07-12  - .2 hours
# 2016-07-12  - 1.1 hours
# 2016-07-13  - 8.3 hours
# 2016-07-13  - .7 hours
# 2016-07-13  - .3 hours
# 2016-07-13  - .4 hours
# 2016-07-13  - 2.3 hours
# 2016-07-13  - .7 hours