nodejs Version Manager utilizing update-alternatives

node-version-manager.sh

#!/bin/bash

if [ "$EUID" != "0" ]; then
    sudo $0 $@;
    exit 1;
fi

BIN_DIR=/usr/bin
NODE_DIR=/usr/local/node;
NODE_VERSION=""
NODE_VERSION_DIR=""

_check_version() {
    local VERSION=$1

    if [[ "" = "$VERSION" ]] ; then
        select VERSION in $NODE_DIR/v[0-9]* ; do
            if [[ ! "" = "$VERSION" ]] ; then
                VERSION=$(basename $VERSION)
                break
            fi
        done
    fi
    if [[ ! -d "$NODE_DIR/$VERSION" ]] ; then
        echo "E: $NODE_DIR/$VERSION is not a directory"
        exit 1
    fi

    NODE_VERSION=$VERSION
    NODE_VERSION_DIR=$NODE_DIR/$NODE_VERSION;
}

_install(){
    local FILE
    local NAME
    local COMMANDS

    for FILE in $NODE_VERSION_DIR/bin/* ; do
        NAME=$(basename $FILE)
        if [[ "node" = "$NAME" ]] ; then
            COMMANDS="--install $BIN_DIR/node node $FILE 100 $COMMANDS"
        else
            COMMANDS="$COMMANDS --slave $BIN_DIR/$NAME $NAME $FILE"
        fi
    done

    update-alternatives $COMMANDS
    $NODE_VERSION_DIR/lib/node_modules/npm/configure --prefix=$NODE_VERSION_DIR
}

_switch(){
    update-alternatives --set node $NODE_VERSION_DIR/bin/node
}

_remove(){
    update-alternatives --remove node $NODE_VERSION_DIR/bin/node
}

case "$1" in
    install|switch|remove)
        _check_version $2 && _$1
        ;;
    *)
        echo "Usage: $0 (install|switch|remove)";
        ;;
esac