shell script 按照文件命名方式移動最新文件

#---------------------------------------------------
#-----move the newest file '*.txt'
#---- in current directory to 'new' folder
#----------------------------------------------
new_folder='./new'
file_partten='*.txt'
#if dir exists?
if [ ! -d $new_folder ]; then
	mkdir $new_folder
fi

files=`ls $new_folder`
#if dir is null?
if [ ! -z "$files" ]; then
	rm -rf $new_folder
	mkdir $new_folder
fi
#find newest file
new_file=`ls -t $file_partten|sed -n '1p'`
#copy
cp $new_file $new_folder
#truncate dir
rm $file_partten