question2.sh

#!/bin/bash

declare -A SEASON_COUNTER

for fn in `cat comptagevelo2009-20162.csv`; do

    RAW_BIKE_COUNTER=$(echo $fn | awk -F '/' '{print $3}' | cut -b 12-)

    MY_DATE_STR=$(cut --output-delimiter=" " -f 3,2,1 -d '/' <(echo $fn | head -c 10) )
    MY_DATE=($MY_DATE_STR)
    YEAR=${MY_DATE[2]}
    MONTH=${MY_DATE[1]}
    DAY=${MY_DATE[0]}
    _DAY_OF_YEAR=$(date --date="$YEAR-$MONTH-$DAY 00:00:00" "+%j")

    # Force base 10.
    #Date command return leading 0
    DAY_OF_YEAR=10#$_DAY_OF_YEAR

    SEASON=""
    if ((  80  <=  $DAY_OF_YEAR &&  $DAY_OF_YEAR <= 171  )); then
	SEASON="spring"
    elif ((  172  <=  $DAY_OF_YEAR &&  $DAY_OF_YEAR <= 265  )) ; then
	     SEASON="summer"
	 elif ((  266  <=  $DAY_OF_YEAR &&  $DAY_OF_YEAR <= 354  )) ; then
		  SEASON="autumn"
	      else
		  SEASON="winter"
	      fi

    LINE_BIKE_COUNT=$(echo $RAW_BIKE_COUNTER | awk -F',' '{s+=$1} END {print s}')
    # echo $SEASON
    SEASON_COUNTER[$SEASON]=$((${SEASON_COUNTER[$SEASON]} + ${LINE_BIKE_COUNT}))

done

echo spring : ${SEASON_COUNTER["spring"]}
echo summer : ${SEASON_COUNTER["summer"]}
echo autumn : ${SEASON_COUNTER["autumn"]}
echo winter : ${SEASON_COUNTER["winter"]}