Add a readability check to that file

check_file_age

@@ -150,6 +150,9 @@ main() {
 	if [ -z "${_args[0]}" ]; then
 		error "Must specify a file" 50
 	fi
+	if ! [ -r "${_args[0]}" ]; then
+		error "File is unreadable: ${_args[0]}" 50
+	fi
 	if ! (( _optcritthresh > 0 )) 2>/dev/null; then
 		error "Critical threshold must be an integer greater than 0" 50
 	fi