#!/bin/bash 
function numeric_to_string() 
{ 
    case "$1" in 
        1) 
            echo "Um" 
            ;; 
        2) 
            echo "Dois" 
            ;; 
        3) 
            echo "Três" 
            ;; 
        $1) 
            echo "Numero $1" 
    esac 
    return 0 
} 
numeric_to_string $1