#!/bin/sh

if [ "$1" == "-h" ]; then
    cat<<EOF
Usage: ${0##*/} PATH

Display PATH one entry per line. If PATH is not provided, use \$PATH by
default. PATH must be a ':' separated list.

EOF

    exit
fi

if [ $# -ne 0 ]; then
    ARG="$1"
else
    ARG="$PATH"
fi

echo "$ARG" | sed 's/:/\n/g'