확장자 일괄 변환

특정 확장자 일괄 변환

ex) html, htm, csv -> txt

#!/bin/sh

for filename in *

do

    case "$filename" in

        *.htm | *.html | *.csv )

            headname=${filename%.*}

            echo $headname  

            #mv "$filename" "${headname}.txt"

            ;;

    esac

done