hxtools/suser/rot13

#!/bin/sh
# SPDX-License-Identifier: MIT
#
#	do ROT13 substituion cipher

if [ "$#" -gt 1 ]; then
	cat "$@" | tr 'A-Za-z' 'N-ZA-Mn-za-m';
elif [ "$#" -eq 1 ]; then
	exec tr 'A-Za-z' 'N-ZA-Mn-za-m' <"$1";
else
	exec tr 'A-Za-z' 'N-ZA-Mn-za-m';
fi;