Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!seismo!lll-lcc!mordor!sri-spam!sri-unix!hplabs!hpcea!hpfcdc!hpfcdt!ajs
From: ajs@hpfcdt.UUCP
Newsgroups: net.sources
Subject: Re: Korn Shell LRU Directory History
Message-ID: <7930001@hpfcdt.HP.COM>
Date: Mon, 30-Mar-87 18:51:31 EST
Article-I.D.: hpfcdt.7930001
Posted: Mon Mar 30 18:51:31 1987
Date-Received: Sat, 4-Apr-87 06:22:44 EST
References: <337@nud.UUCP>
Organization: HP Fort Collins, CO
Lines: 141

# Here's yet another way to remember and re-use old directories.  This one
# remembers everywhere you've been during a login session, and lets you
# pick from a sorted menu ("mcd") or list a Pareto-style summary ("lcd").
# I've found it only occasionally useful, but fast and painless.  If
# nothing else you might find these functions educational.

# This is a shell archive.  Remove anything before this line,
# then unpack it by saving it in a file and typing "sh file".
#
# Wrapped by ajs at hpfcdt on Mon Mar 30 16:49:13 1987
#
# This archive contains:
#	ksh.cd	
#
# Error checking via wc(1) will be performed.

echo x - ksh.cd
cat >ksh.cd <<'@EOF'

# ksh functions to remember directory changes and let you pick (from a menu)
# directories to which to cd.

# Usage:
# Read this file with ". file", or put it in your .profile or .kshrc.  Then
# cd as usual.  Say "mcd" to get a menu of places you've been, to pick from.
# Say "lcd" to list your cd history, most-visited first.

# Warning:  Some things don't work right due to ksh deficiencies:
#
# - The typeset -x below is intended to cause DIRHIST[] to be exported to
#   subshells.  But ksh only exports the first element of any array (and
#   that's clobbered when mycd() is declared).  Too bad.
#
# - For some reason, the quotes around "$@" in the select in mcd() cause menu
#   item 1 to be munged sometimes, reason unknown.  Remove the quotes if this
#   is a problem and you never visit a directory with a blank or tab in its
#   name.


# INITIALIZE:
#
# Note that during .profile, $PWD is not set yet.

	if [ -z "${DIRHIST:-}" ]		# not already set.
	then
	    DIRHIST="${PWD:-$HOME}"
	fi

	typeset -x DIRHIST
	typeset -x DIRCOUNT=1		# just for fun, how often before.


# FUNCTION mycd():  DO A CD AND REMEMBER ALL DIRS VISITED:

	alias cd=mycd			# alias > built-in > function.

	mycd()
	{
	    typeset -i dirat=0		# current saved dir index; local var.
	    typeset -i dirs=${#DIRHIST[*]}
					# number of entries in "global" array.

	# Do the change:

	    if 'cd' "${@-$HOME}"	# call shell built-in.
	    then			# only if it succeeded.

	# See if new directory name (note, full name) is already known:

		while [ $dirat -lt $dirs ]
		do
		    if [ "${DIRHIST[$dirat]}" = "$PWD" ]
		    then
			break
		    fi

		    (( dirat=dirat + 1 ))
		done

	# Save new, or tell count for old:

		if [ $dirat -ge $dirs ]
		then
		    DIRHIST[$dirat]="$PWD"
		    DIRCOUNT[$dirat]=1
		    echo "(first time here)"
		else
		    echo "(previous: ${DIRCOUNT[$dirat]})"
		    (( DIRCOUNT[$dirat]=${DIRCOUNT[$dirat]} + 1 ))
		fi
	    fi

	} # mycd().


# FUNCTION mcd():  DO A CD CHOOSING FROM A MENU:

	mcd()
	{
	    set -- "${DIRHIST[@]}"	# copy to positional parameters.
	    set -s			# sort them.  (remove if not desired)

	    select dir in "$@"		# choose one.
	    do
		if [ "${dir-}" ]	# valid response.
		then
		    echo "+ cd $dir"
		    mycd "$dir"		# use function for side-effects.
		else
		    echo "cd: no change"
		fi

		break
	    done

	} # mcd().


# FUNCTION lcd():  LIST CD HISTORY:

	lcd()
	{
	    typeset -i dirat=0		# current saved dir index; local var.
	    typeset -i dirs=${#DIRHIST[*]}	# entries in "global" array.

	    while [ $dirat -lt $dirs ]
	    do
		echo "${DIRCOUNT[$dirat]}\t${DIRHIST[$dirat]}"
		(( dirat=dirat + 1 ))
	    done | sort +0nr -1

	} # lcd().
@EOF
if test "`wc -lwc <ksh.cd`" != '    114    444   2687'
then
	echo ERROR: wc results of ksh.cd are `wc -lwc <ksh.cd` should be     114    444   2687
fi

chmod 444 ksh.cd

exit 0