#!/bin/bash
echo Script name: $0
echo $# arguments

if [ "$#" -lt 1 ];
    then echo "Nenhum parâmetro informado!"
    exit 1
fi

input="${*:1}"
reverse=""

len=${#input}

for (( i=$len - 1; i >= 0 ; i-- ))
do
    reverse="$reverse${input:$i:1}"
done

echo "$reverse"