Source Code 1992 March/Source_Code_CD-ROM_Walnut_Creek_March_1992.iso/usenet/altsrcs/1/1874

Internet Message Format | 1990-12-28 | 4.0 KB

From: [e-mail] (David Barto)
Newsgroups: comp.unix.shell,alt.sources
Subject: Re: Pushd, popd, dirs for stock SysV.3 Bourne shell
Message-ID: <[e-mail]>
Date: 27 Sep 90 16:19:05 GMT

In article <[e-mail]> [e-mail] (Piercarlo Grandi) writes:
>
>You will find appended a small shell script that defines under a stock
>System V Bourne shell the pushd, popd, dirs commands of csh(1). They are
>trivially adapted to the Korn shell. I have taken care to make them as
>robust as possible.
>

pushd, popd, and dirs --- written by Chris Bertin
Pixel Computer Inc. ...!wjh12!pixel!pixutl!chris
as modified by Patrick Elam of GTRI
modified by david barto to allow 'pushd +n'

cd is a function, which uses the 'builtin' keyword, available for
those who have the BRL mods to the shell.  (I think this can be changed
to 'eval'.)  It will look for PCDPATH and do chdirs down that path if
the directory can be found on it.

PCDPATH=". $HOME /burt/prj/common /burt/prj/sparc /archive2"
export PCDPATH
-----

cd () {
    PREVDIR="$CWD"
    result=1
    if [ $# -lt 1 ] ; then
        builtin cd
        result=0
    elif [ -d $1 ] ; then
        builtin cd "$1"
        result=0
    else
        for i in $PCDPATH
        do
        nxtdir=$i/$1
        # echo "try $nxtdir"
        if [ $result != 0 -a -d $nxtdir ] ; then
            builtin cd "$nxtdir"
            result=0
        fi
        done
        unset nxtdir
    fi
    if [ $result != 0 ] ; then
        echo "$1: directory not found"
    else
        CWD=`pwd` export CWD
        set +u
        if [ "$CWD" = "$HOME" ]
        then
        PFX="$HOST"
        PS1=:~
        else
        PS1=`echo "$CWD" | sed -e "s!^$HOME!~!"` PFX="$HOST":
        fi
        umask 022
        echo "$CWD" | egrep -s "/burt/prj/common|/x"
        [ $? = 0 ] && umask 002
        if [ "$TERM" = "wy75" ]
        then
        wy75-title $PS1
        PS1="$PFX %e_ "
        elif [ "$TWM_RUNNING" = 1 ]
        then
        if [ "$TTY" != "" ]
        then
            twm-title "$TTY:$PFX$PS1"
        else
            twm-title "XX:$PFX$PS1"
        fi
        PS1="%e_ "
        else
        PS1="$PFX$PS1 %t%n%e_ "
        fi
        unset PFX
        set -u
    fi
    return $result
}

# pushd, popd, and dirs --- written by Chris Bertin
# Pixel Computer Inc. ...!wjh12!pixel!pixutl!chris
# as modified by Patrick Elam of GTRI
# modified by david barto to allow 'pushd +n'

pushd () {
    SAVE=`pwd`
    _DSTACK="$SAVE $_DSTACK"
    if [ "$1" = "" ]
    then
        if [ "$_DSTACK" = "$SAVE " ]
        then
            echo "pushd: directory stack empty."
            _DSTACK=""
            return 1
        fi
        set $_DSTACK
        cd $2
        set $_DSTACK
        shift 2
        _DSTACK="$SAVE $*"
    else
        case "$1" in
        +*)
            count=`echo $1 | sed 's/+//'`
            set $_DSTACK
            if [ $count -ge $# ] ; then
                echo "pushd: directory stack not that deep"
                shift
                _DSTACK=$*
                return 1
            fi
            TMP=
            while [ $count -gt 0 ]
            do
                TMP="$TMP $1"
                shift
                count=`expr $count - 1`
            done
            TD=$1
            shift
            _DSTACK="$TMP $*"
            unset TMP
            if [ -d $TD ]
            then
                cd $TD >&-
                unset TD
            else
                popd > /dev/null
                return 1
            fi
            ;;
        *)
            cd $1
            if [ $? -eq 1 ] ; then
                popd > /dev/null
                return 1
            fi
            ;;
        esac
    fi
    dirs
    return 0
}

popd () {
    if [ "$_DSTACK" = "" ]; then
        echo "popd: Directory stack empty"
        return 1
    fi
    case "$1" in
    +*)
        count=`echo $1 | sed 's/+//'`
        case "$count" in
        0)
            echo "popd: Must have positive count"
            return 1
            ;;
        1)
            popd
            return 0
            ;;
        *)
            _TMPSTK="`pwd` $_DSTACK"
            set $_TMPSTK
            if [ $count -gt $# ]; then
                echo "pushd: directory stack not that deep"
                return 1
            fi
            TMP=
            while [ $count -ge 1 ]
            do
                TMP="$TMP $1"
                shift
                count=`expr $count - 1`
            done
            shift        # trash dir requested
            _DSTACK="$* $TMP"
            set $_DSTACK
            shift        # trash 'pwd' from the top of the stack
            _DSTACK="$*"
            ;;
        esac
        ;;
    *)
        set $_DSTACK
        cd $1
        set $_DSTACK
        shift
        _DSTACK=$*
        ;;
    esac
    dirs
    return 0
}

dirs () {
    echo "`pwd` $_DSTACK"
    return 0
}

xchng () {    # exchanged top two entries on the stack
    if [ "$_DSTACK" = "" ]
    then
        echo exchange directory stack empty
        return 1
    else
        pushd
        return 0
    fi
}
--
David Barto    uunet!megatek!barto    [e-mail]