#!/bin/bash
   # This script checks the existence of a file
   if [[ $# -ne 1 ]] ; then
       echo "Usage: $0 filename"
       exit 1
   fi
   echo "Checking..."
   if [[ -f $1 ]] ; then
       echo "$1 existe."
   else
       echo "$1 não existe"
   fi
   echo "...done."