# Convert DATE type
sed -i -E 's,([0-9]{4})-([0-9]{2})-([0-9]{2}),\2/\3/\1,g' 20??.csv
# Remove ^M for 2021.csv only! ^M => Ctrl+v + Ctrl+m
sed -i 's/^M//' 2021.csv
# Delete the last ,
sed -i 's/,$//' 20??.csv
# Delete Empty Line
sed -i '/^$/d' 20??.csv
# Convert DATE type 2022-01-31 ==> 01/31/2022
#sed -i -E 's,([0-9]{4})-([0-9]{2})-([0-9]{2}),\2/\3/\1,g' 2015.csv
#sed -i -E 's,([0-9]{4})-([0-9]{2})-([0-9]{2}),\2/\3/\1,g' 2016.csv
#sed -i -E 's,([0-9]{4})-([0-9]{2})-([0-9]{2}),\2/\3/\1,g' 2017.csv
#sed -i -E 's,([0-9]{4})-([0-9]{2})-([0-9]{2}),\2/\3/\1,g' 2018.csv
#sed -i -E 's,([0-9]{4})-([0-9]{2})-([0-9]{2}),\2/\3/\1,g' 2019.csv
#sed -i -E 's,([0-9]{4})-([0-9]{2})-([0-9]{2}),\2/\3/\1,g' 2020.csv
#sed -i -E 's,([0-9]{4})-([0-9]{2})-([0-9]{2}),\2/\3/\1,g' 2021.csv
# Delete the last ,
#sed -i 's/[,]$//' 2015.csv
#sed -i 's/[,]$//' 2016.csv
#sed -i 's/[,]$//' 2017.csv
#sed -i 's/[,]$//' 2018.csv
#sed -i 's/[,]$//' 2019.csv
#sed -i 's/[,]$//' 2020.csv
#sed -i 's/[,]$//' 2021.csv
# Delete Empty Line
#sed -i '/^$/d' 2015.csv
#sed -i '/^$/d' 2016.csv
#sed -i '/^$/d' 2017.csv
#sed -i '/^$/d' 2018.csv
#sed -i '/^$/d' 2019.csv
#sed -i '/^$/d' 2020.csv
#sed -i '/^$/d' 2021.csv
# Delete lines containing keywords
#sed -i '/"OP_UNIQUE_CARRIER/d' flights.csv
# Remove ^M end of file
#sed -i 's/^M//' 2021.csv
# Remove ^Z end of file
#sed -i 's/^Z$//' 1
#tail -n 1 2016.csv | wc -c | xargs -I {} truncate "$file" -s -{}