:
# NAME:
#	ksh.cdhist - cd history for ksh
#
# DESCRIPTION:
#	This package provides a nice cd history mechanism for ksh.
#
#.nf
#
#	cd -l		lists history
#	cd -"n"		cd to "n"th directory in list
#.fi
#
#	It is pretty simple to use.
#
# BUGS:
#	It will not work with pd-ksh prior to v5.
#

# RCSid:
#	$Id: ksh.cdhist,v 1.1.1.1 2002/01/15 09:16:22 sjg Exp $


alias cd=_cd

# incase $HOME is not writeable...
if [ "$CDHISTFILE" ]; then
 	[ -w `dirname $CDHISTFILE` ] || CDHISTFILE=/tmp/.cd_hist$$
fi

_cd() {
	typeset -i cdlen i
	typeset t

	if [ $# -eq 0 ]
	then
		set -- $HOME
	fi

	if [ "$CDHISTFILE" -a -r "$CDHISTFILE" ] # if directory history exists
	then
		typeset CDHIST
		i=-1
		while read -r t			# read directory history file
		do
			CDHIST[i=i+1]="$t"
		done <$CDHISTFILE
	fi

	if [ "${CDHIST[0]}" != "$PWD" -a "$PWD" != "" ]
	then
		_cdins				# insert $PWD into cd history
	fi

	cdlen=${#CDHIST[*]}			# number of elements in history

	case "$@" in
	-)					# cd to new dir
		if [ "$OLDPWD" = "" ] && ((cdlen>1))
		then
			'print' ${CDHIST[1]}
			'cd' "${CDHIST[1]}"
			_pwd
		else
			'cd' "$@"
			_pwd
		fi
		;;
	-l)					# print directory list
		typeset -R3 num
		((i=cdlen))
		while (((i=i-1)>=0))
		do
			num=$i
			'print' "$num ${CDHIST[i]}"
		done
		return
		;;
	-[0-9]|-[0-9][0-9])			# cd to dir in list
		if (((i=${1#-})<cdlen))
		then
			'print' ${CDHIST[i]}
			'cd' "${CDHIST[i]}"
			_pwd
		else
			'cd' "$@"
			_pwd
		fi
		;;
	-*)					# cd to matched dir in list
		t=${1#-}
		i=1
		while ((i<cdlen))
		do
			case ${CDHIST[i]} in
			*$t*)
				'print' ${CDHIST[i]}
				'cd' "${CDHIST[i]}"
				_pwd
				break
				;;
			esac
			((i=i+1))
		done
		if ((i>=cdlen))
		then
			'cd' "$@"
			_pwd
		fi
		;;
	*)					# cd to new dir
		'cd' "$@"
		_pwd
		;;
	esac

	_cdins					# insert $PWD into cd history

	if [ "$CDHISTFILE" ]
	then
		cdlen=${#CDHIST[*]}		# number of elements in history

		i=0
		while ((i<cdlen))
		do
			'print' -r ${CDHIST[i]}	# update directory history
			((i=i+1))
		done >$CDHISTFILE
	fi
}

# insert $PWD into cd history - meant to be called only by _cd
_cdins() {

	typeset -i i

	((i=0))
	while ((i<${#CDHIST[*]}))		# see if dir is already in list
	do
		if [ "${CDHIST[$i]}" = "$PWD" ]
		then
			break
		fi
		((i=i+1))
	done

	if ((i>22))				# limit max size of list
	then
		i=22
	fi

	while (((i=i-1)>=0))			# bump old dirs in list
	do
		CDHIST[i+1]=${CDHIST[i]}
	done

	CDHIST[0]=$PWD				# insert new directory in list
}


_pwd() {
	if [ -n "$ECD" ]
	then
		pwd 1>&6
	fi
}