#!/usr/bin/env bash function usage() { echo if [ -n "$1" ];then echo -e "Error: $1\n" fi cat <" EOF exit 1 } while getopts h opt ; do case $opt in h) usage ;; *) usage ;; esac done [ $# -ne "1" ] && usage "Wrong number of arguments" cert_file=$1 openssl x509 -noout -text -in $cert_file exit $?