Linux中这个哪里错了，很不解，想快速解答

Question

#!/bin/bash
echo -e "Please input a filename,I will check the filename's type and\permission.\n\n"
read -p "Input a filename :"
test -z $filename && echo "You MUST input a filename: "&& exit 0
test !-e $filename && echo "The filename'$filename'Do NOT exist" && exit 0
test -f $filename && filetype="regular file"
test -d $filename && filetype="directory"
test -r $filename && perm="readable"
test -w $filename && perm="$perm writable"
test -x $filename && perm="$perm executable"
echo "The filename: $filename is a $filetype"
echo "And the permissions are: $perm"

Answer 1

read -p "Input a filename :" filename