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Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!ucla-cs!sdcrdcf!trwrb!simpson
From: simpson@trwrb.UUCP
Newsgroups: net.sources
Subject: Re: Prompt wars, revisited.
Message-ID: <1744@trwrb.UUCP>
Date: Thu, 2-Apr-87 08:25:56 EST
Article-I.D.: trwrb.1744
Posted: Thu Apr  2 08:25:56 1987
Date-Received: Sun, 5-Apr-87 01:03:52 EST
References: <300@cpro.UUCP> <1500@umd5.umd.edu> <65@esquire.UUCP>
Reply-To: simpson@trwrb.UUCP (Scott Simpson)
Distribution: world
Organization: TRW EDS, Redondo Beach, CA
Lines: 87

Here are an implementation of pushd and popd in the Korn shell that I put
in a file .kshrc.  I also use sysline(1) and put the prompt in the bottom
of the terminal screen by writing to the .who file.

dirstack=
function chdir
{
    integer cutoff

    \cd $@ || return 1
    let cutoff="${#HOME} + 1"
    if [ "`pwd | colrm $cutoff`" = ~ ]; then
	echo \~`pwd | colrm 1 ${#HOME}` > ~/.who # .who is read by sysline(1)
    else
	pwd > ~/.who
    fi
}
alias cd=chdir
alias back='chdir -'
function pushd
{
    integer cutoff 

    if [ $# -ne 1 ];	then
	return 1
    fi
    chdir $1 || return 1
    let cutoff="${#HOME} + 1"
    dirstack="$OLDPWD $dirstack"
    for i in `pwd` $dirstack; do
        if [ "`echo $i | colrm $cutoff`" = ~ ]; then
	    echo -n "~`echo $i | colrm 1 ${#HOME}` "
	else
	    echo  -n "$i "
	fi
    done
    echo
}
function popd
{
    integer cutoff

    if [ $# -ne 0 ];	then
	return 1
    fi
    set -- $dirstack
    if [ $# -le 0 ];	then
	echo Directory stack empty
	return 1
    fi
    chdir $1 || return 1
    let cutoff="${#HOME} + 1"
    shift
    dirstack=$*
    if [ "`pwd | colrm $cutoff`" = ~ ]; then
	echo \~`pwd | colrm 1 ${#HOME}`
    else
	pwd
    fi
}
function dirs
{
    integer cutoff
    
    let cutoff="${#HOME} + 1"
    for i in `pwd` $dirstack; do
	if [ "`echo $i | colrm $cutoff`" = ~ ]; then
	    echo -n "~`echo $i | colrm 1 ${#HOME}` "
	else
	    echo -n "$i "
	fi
    done
    echo
}

This file gets read on Korn shell invocation by putting the lines
    ENV=~/.kshrc
    export ENV
    . $ENV
in my .profile. I also add the lines
    echo \~ > .who
    sysline -Dqj
to invoke sysline in my .profile.
-- 
		Scott Simpson
		TRW Electronics and Defense Sector
		...{decvax,ihnp4,ucbvax}!trwrb!simpson