Bash getopts example

gistfile1.bash

#!/bin/bash

#   Example of using bash-builtin getopts to parse script arguments
#   Copyright (C) 2011  Radek Pazdera

#   This program is free software: you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation, either version 3 of the License, or
#   (at your option) any later version.

#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.

#   You should have received a copy of the GNU General Public License
#   along with this program.  If not, see <http://www.gnu.org/licenses/>.

while getopts "123:" OPTION
do
  case $OPTION in
    1)  echo "Uno";;
    2)  echo "Dos";;
    3)  echo "Tres: $OPTARG";;
    \?) exit 1;;
  esac
done