date_ls.sh

#! /bin/bash
# @idyoung 2020.07.20
# Use this script in place of `ls` to list directories in a format 06Jun2020 in chronological order

export matches=`ls | grep "^[0-9][0-9][[:alpha:]][[:alpha:]][[:alpha:]][0-9][0-9][0-9][0-9]"`
export prefixed_matches=""
for match in $matches; do
     export day=${match:0:2}
     export month_alpha=${match:2:3}
     case $month_alpha in
        "Jan")
            export month="01"
            ;;
        "Feb")
            export month="02"
            ;;
        "Mar")
            export month="03"
            ;;
        "Apr")
            export month="04"
            ;;
        "May")
            export month="05"
            ;;
        "Jun")
            export month="06"
            ;;
        "Jul")
            export month="07"
            ;;
        "Aug")
            export month="08"
            ;;
        "Sep")
            export month="09"
            ;;
        "Oct")
            export month="10"
            ;;
        "Nov")
            export month="11"
            ;;
        "Dec")
            export month="12"
            ;;
        *)
            echo "cannot interpret argument $match"
            export month="13"
            ;;
    esac
    export year=${match:5:4}
    if [ $month != "13" ]; then
        export prefixed_matches="${prefixed_matches} ${year}${month}${day}_${match}"
    fi
done
echo $prefixed_matches | sed "s: :\n:g" | sort | sed "s:.*_::"