Shell Programming and Scripting

#!/bin/sh

case $# in
0)echo Usage: dosRename file >&2
	   ;;
*)for file
		do
				case $file in

				[A-Za-z0-9]*\.\*) type=main
					   ;;
				\*\.[A-Za-z0-9]* )type=extension
					   ;;
				esac
		#echo $type
		done

		endFile=$file

		while [ $# -ne 1  ]
		do
				case $type in
				'extension')	extension=`echo $endFile |sed -e 's/\*\./\./'`
								newfile=`echo $1 |sed -e "s/\.[A-Za-z0-9]*/$extension/"`
								echo  "if $1 had been renamed it would now be $newfile"
							 #   mv $1 $newfile
					   ;;
				'main')		 fileName=`echo $endFile | sed -e 's/\.\*//'`
								newFile=`echo $1 | sed -e "s/[A-Za-z0-9]*\.\(.*[A-Za-z0-9]*\)/$fileName\.\1/"`
								echo "if $1 had been renamed it would now be $newFile"
							#	mv $1 $newFile
					   ;;
				esac
				shift 1
		done
	   ;;

esac