#!/bin/ksh
# List items in colon-separated list on one line per item.
# With no arguments, lists contents of PATH variable.
# Alternative strings can be passed, e.g:
# path $CLASSPATH
# William Robertson, www.williamrobertson.net

usage="'${0##*/}' utility, William Robertson 2003, www.williamrobertson.net.
\nUsage: ${0##*/} [ -u ] [ pathstring ]
\nOptions: -u = Unique
\nOptional pathstring defaults to \$PATH"

while getopts ":u" opt; do
	case $opt in
		u ) unique=Y ;;
		* ) print -u2 ${usage}; exit 2;;
	esac
done
shift $(($OPTIND -1))

path=${1:-$PATH}
accumulated=""
standardIFS="${IFS}"
IFS=':'

for d in ${path} ; do
	if [[ :${accumulated}: = *:${d}:* ]]
	then
		[[ ${unique} = Y ]] || print ${d}
	else
		print $d
		accumulated=${accumulated}:${d}
	fi
done
IFS="${standardIFS}"