#!/bin/bash
OPTIONS="-twb -y --width=200"
OPTIONS="-twb"
left="$1"
and="$2"
right="$3"
differ="$4"
if [ "$and" = "and" -a "$differ" = "differ" ] ; then
    diff  $OPTIONS "$left" "$right"
else
    echo "Usage:"
    echo "   File ${left-file} and ${right-file} differ"
    exit 1
fi