GiuseppeLota

usage() { echo "Usage: $0 [-s <45|90>] [-p <string>]" 1>&2; exit 1; }

while getopts ":s:p:" o "$@"; 
do
    case $o in
        s) s=${OPTARG}
            ((s == 45 || s == 90)) || usage;; 

        p)p=${OPTARG};;